smack_lsm.c 116.6 KB
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/*
 *  Simplified MAC Kernel (smack) security module
 *
 *  This file contains the smack hook function implementations.
 *
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 *  Authors:
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 *	Casey Schaufler <casey@schaufler-ca.com>
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 *	Jarkko Sakkinen <jarkko.sakkinen@intel.com>
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 *
 *  Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com>
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 *  Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
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 *                Paul Moore <paul@paul-moore.com>
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 *  Copyright (C) 2010 Nokia Corporation
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 *  Copyright (C) 2011 Intel Corporation.
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 *
 *	This program is free software; you can redistribute it and/or modify
 *	it under the terms of the GNU General Public License version 2,
 *      as published by the Free Software Foundation.
 */

#include <linux/xattr.h>
#include <linux/pagemap.h>
#include <linux/mount.h>
#include <linux/stat.h>
#include <linux/kd.h>
#include <asm/ioctls.h>
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#include <linux/ip.h>
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#include <linux/tcp.h>
#include <linux/udp.h>
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#include <linux/dccp.h>
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#include <linux/icmpv6.h>
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#include <linux/slab.h>
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#include <linux/mutex.h>
#include <linux/pipe_fs_i.h>
#include <net/cipso_ipv4.h>
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#include <net/ip.h>
#include <net/ipv6.h>
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#include <linux/audit.h>
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#include <linux/magic.h>
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#include <linux/dcache.h>
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#include <linux/personality.h>
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#include <linux/msg.h>
#include <linux/shm.h>
#include <linux/binfmts.h>
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#include <linux/parser.h>
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#include <linux/fs_context.h>
#include <linux/fs_parser.h>
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#include "smack.h"

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#define TRANS_TRUE	"TRUE"
#define TRANS_TRUE_SIZE	4

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#define SMK_CONNECTING	0
#define SMK_RECEIVING	1
#define SMK_SENDING	2

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#ifdef SMACK_IPV6_PORT_LABELING
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DEFINE_MUTEX(smack_ipv6_lock);
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static LIST_HEAD(smk_ipv6_port_list);
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#endif
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static struct kmem_cache *smack_inode_cache;
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struct kmem_cache *smack_rule_cache;
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int smack_enabled;
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#define A(s) {"smack"#s, sizeof("smack"#s) - 1, Opt_##s}
static struct {
	const char *name;
	int len;
	int opt;
} smk_mount_opts[] = {
	A(fsdefault), A(fsfloor), A(fshat), A(fsroot), A(fstransmute)
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};
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#undef A

static int match_opt_prefix(char *s, int l, char **arg)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(smk_mount_opts); i++) {
		size_t len = smk_mount_opts[i].len;
		if (len > l || memcmp(s, smk_mount_opts[i].name, len))
			continue;
		if (len == l || s[len] != '=')
			continue;
		*arg = s + len + 1;
		return smk_mount_opts[i].opt;
	}
	return Opt_error;
}
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#ifdef CONFIG_SECURITY_SMACK_BRINGUP
static char *smk_bu_mess[] = {
	"Bringup Error",	/* Unused */
	"Bringup",		/* SMACK_BRINGUP_ALLOW */
	"Unconfined Subject",	/* SMACK_UNCONFINED_SUBJECT */
	"Unconfined Object",	/* SMACK_UNCONFINED_OBJECT */
};

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static void smk_bu_mode(int mode, char *s)
{
	int i = 0;

	if (mode & MAY_READ)
		s[i++] = 'r';
	if (mode & MAY_WRITE)
		s[i++] = 'w';
	if (mode & MAY_EXEC)
		s[i++] = 'x';
	if (mode & MAY_APPEND)
		s[i++] = 'a';
	if (mode & MAY_TRANSMUTE)
		s[i++] = 't';
	if (mode & MAY_LOCK)
		s[i++] = 'l';
	if (i == 0)
		s[i++] = '-';
	s[i] = '\0';
}
#endif

#ifdef CONFIG_SECURITY_SMACK_BRINGUP
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static int smk_bu_note(char *note, struct smack_known *sskp,
		       struct smack_known *oskp, int mode, int rc)
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{
	char acc[SMK_NUM_ACCESS_TYPE + 1];

	if (rc <= 0)
		return rc;
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	if (rc > SMACK_UNCONFINED_OBJECT)
		rc = 0;
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	smk_bu_mode(mode, acc);
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	pr_info("Smack %s: (%s %s %s) %s\n", smk_bu_mess[rc],
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		sskp->smk_known, oskp->smk_known, acc, note);
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	return 0;
}
#else
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#define smk_bu_note(note, sskp, oskp, mode, RC) (RC)
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#endif

#ifdef CONFIG_SECURITY_SMACK_BRINGUP
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static int smk_bu_current(char *note, struct smack_known *oskp,
			  int mode, int rc)
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{
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	struct task_smack *tsp = smack_cred(current_cred());
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	char acc[SMK_NUM_ACCESS_TYPE + 1];

	if (rc <= 0)
		return rc;
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	if (rc > SMACK_UNCONFINED_OBJECT)
		rc = 0;
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	smk_bu_mode(mode, acc);
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	pr_info("Smack %s: (%s %s %s) %s %s\n", smk_bu_mess[rc],
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		tsp->smk_task->smk_known, oskp->smk_known,
		acc, current->comm, note);
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	return 0;
}
#else
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#define smk_bu_current(note, oskp, mode, RC) (RC)
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#endif

#ifdef CONFIG_SECURITY_SMACK_BRINGUP
static int smk_bu_task(struct task_struct *otp, int mode, int rc)
{
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	struct task_smack *tsp = smack_cred(current_cred());
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	struct smack_known *smk_task = smk_of_task_struct(otp);
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	char acc[SMK_NUM_ACCESS_TYPE + 1];

	if (rc <= 0)
		return rc;
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	if (rc > SMACK_UNCONFINED_OBJECT)
		rc = 0;
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	smk_bu_mode(mode, acc);
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	pr_info("Smack %s: (%s %s %s) %s to %s\n", smk_bu_mess[rc],
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		tsp->smk_task->smk_known, smk_task->smk_known, acc,
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		current->comm, otp->comm);
	return 0;
}
#else
#define smk_bu_task(otp, mode, RC) (RC)
#endif

#ifdef CONFIG_SECURITY_SMACK_BRINGUP
static int smk_bu_inode(struct inode *inode, int mode, int rc)
{
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	struct task_smack *tsp = smack_cred(current_cred());
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	struct inode_smack *isp = smack_inode(inode);
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	char acc[SMK_NUM_ACCESS_TYPE + 1];

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	if (isp->smk_flags & SMK_INODE_IMPURE)
		pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n",
			inode->i_sb->s_id, inode->i_ino, current->comm);

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	if (rc <= 0)
		return rc;
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	if (rc > SMACK_UNCONFINED_OBJECT)
		rc = 0;
	if (rc == SMACK_UNCONFINED_SUBJECT &&
	    (mode & (MAY_WRITE | MAY_APPEND)))
		isp->smk_flags |= SMK_INODE_IMPURE;
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	smk_bu_mode(mode, acc);
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	pr_info("Smack %s: (%s %s %s) inode=(%s %ld) %s\n", smk_bu_mess[rc],
		tsp->smk_task->smk_known, isp->smk_inode->smk_known, acc,
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		inode->i_sb->s_id, inode->i_ino, current->comm);
	return 0;
}
#else
#define smk_bu_inode(inode, mode, RC) (RC)
#endif

#ifdef CONFIG_SECURITY_SMACK_BRINGUP
static int smk_bu_file(struct file *file, int mode, int rc)
{
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	struct task_smack *tsp = smack_cred(current_cred());
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	struct smack_known *sskp = tsp->smk_task;
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	struct inode *inode = file_inode(file);
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	struct inode_smack *isp = smack_inode(inode);
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	char acc[SMK_NUM_ACCESS_TYPE + 1];

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	if (isp->smk_flags & SMK_INODE_IMPURE)
		pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n",
			inode->i_sb->s_id, inode->i_ino, current->comm);

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	if (rc <= 0)
		return rc;
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	if (rc > SMACK_UNCONFINED_OBJECT)
		rc = 0;
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	smk_bu_mode(mode, acc);
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	pr_info("Smack %s: (%s %s %s) file=(%s %ld %pD) %s\n", smk_bu_mess[rc],
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		sskp->smk_known, smk_of_inode(inode)->smk_known, acc,
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		inode->i_sb->s_id, inode->i_ino, file,
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		current->comm);
	return 0;
}
#else
#define smk_bu_file(file, mode, RC) (RC)
#endif

#ifdef CONFIG_SECURITY_SMACK_BRINGUP
static int smk_bu_credfile(const struct cred *cred, struct file *file,
				int mode, int rc)
{
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	struct task_smack *tsp = smack_cred(cred);
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	struct smack_known *sskp = tsp->smk_task;
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	struct inode *inode = file_inode(file);
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	struct inode_smack *isp = smack_inode(inode);
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	char acc[SMK_NUM_ACCESS_TYPE + 1];

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	if (isp->smk_flags & SMK_INODE_IMPURE)
		pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n",
			inode->i_sb->s_id, inode->i_ino, current->comm);

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	if (rc <= 0)
		return rc;
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	if (rc > SMACK_UNCONFINED_OBJECT)
		rc = 0;
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	smk_bu_mode(mode, acc);
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	pr_info("Smack %s: (%s %s %s) file=(%s %ld %pD) %s\n", smk_bu_mess[rc],
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		sskp->smk_known, smk_of_inode(inode)->smk_known, acc,
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		inode->i_sb->s_id, inode->i_ino, file,
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		current->comm);
	return 0;
}
#else
#define smk_bu_credfile(cred, file, mode, RC) (RC)
#endif

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/**
 * smk_fetch - Fetch the smack label from a file.
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 * @name: type of the label (attribute)
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 * @ip: a pointer to the inode
 * @dp: a pointer to the dentry
 *
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 * Returns a pointer to the master list entry for the Smack label,
 * NULL if there was no label to fetch, or an error code.
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 */
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static struct smack_known *smk_fetch(const char *name, struct inode *ip,
					struct dentry *dp)
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{
	int rc;
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	char *buffer;
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	struct smack_known *skp = NULL;
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	if (!(ip->i_opflags & IOP_XATTR))
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		return ERR_PTR(-EOPNOTSUPP);
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	buffer = kzalloc(SMK_LONGLABEL, GFP_KERNEL);
	if (buffer == NULL)
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		return ERR_PTR(-ENOMEM);
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	rc = __vfs_getxattr(dp, ip, name, buffer, SMK_LONGLABEL);
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	if (rc < 0)
		skp = ERR_PTR(rc);
	else if (rc == 0)
		skp = NULL;
	else
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		skp = smk_import_entry(buffer, rc);
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	kfree(buffer);

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	return skp;
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}

/**
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 * init_inode_smack - initialize an inode security blob
 * @isp: the blob to initialize
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 * @skp: a pointer to the Smack label entry to use in the blob
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 *
 */
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static void init_inode_smack(struct inode *inode, struct smack_known *skp)
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{
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	struct inode_smack *isp = smack_inode(inode);
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	isp->smk_inode = skp;
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	isp->smk_flags = 0;
	mutex_init(&isp->smk_lock);
}

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/**
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 * init_task_smack - initialize a task security blob
 * @tsp: blob to initialize
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 * @task: a pointer to the Smack label for the running task
 * @forked: a pointer to the Smack label for the forked task
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 *
 */
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static void init_task_smack(struct task_smack *tsp, struct smack_known *task,
					struct smack_known *forked)
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{
	tsp->smk_task = task;
	tsp->smk_forked = forked;
	INIT_LIST_HEAD(&tsp->smk_rules);
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	INIT_LIST_HEAD(&tsp->smk_relabel);
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	mutex_init(&tsp->smk_rules_lock);
}

/**
 * smk_copy_rules - copy a rule set
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 * @nhead: new rules header pointer
 * @ohead: old rules header pointer
 * @gfp: type of the memory for the allocation
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 *
 * Returns 0 on success, -ENOMEM on error
 */
static int smk_copy_rules(struct list_head *nhead, struct list_head *ohead,
				gfp_t gfp)
{
	struct smack_rule *nrp;
	struct smack_rule *orp;
	int rc = 0;

	list_for_each_entry_rcu(orp, ohead, list) {
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		nrp = kmem_cache_zalloc(smack_rule_cache, gfp);
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		if (nrp == NULL) {
			rc = -ENOMEM;
			break;
		}
		*nrp = *orp;
		list_add_rcu(&nrp->list, nhead);
	}
	return rc;
}

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/**
 * smk_copy_relabel - copy smk_relabel labels list
 * @nhead: new rules header pointer
 * @ohead: old rules header pointer
 * @gfp: type of the memory for the allocation
 *
 * Returns 0 on success, -ENOMEM on error
 */
static int smk_copy_relabel(struct list_head *nhead, struct list_head *ohead,
				gfp_t gfp)
{
	struct smack_known_list_elem *nklep;
	struct smack_known_list_elem *oklep;

	list_for_each_entry(oklep, ohead, list) {
		nklep = kzalloc(sizeof(struct smack_known_list_elem), gfp);
		if (nklep == NULL) {
			smk_destroy_label_list(nhead);
			return -ENOMEM;
		}
		nklep->smk_label = oklep->smk_label;
		list_add(&nklep->list, nhead);
	}

	return 0;
}

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/**
 * smk_ptrace_mode - helper function for converting PTRACE_MODE_* into MAY_*
 * @mode - input mode in form of PTRACE_MODE_*
 *
 * Returns a converted MAY_* mode usable by smack rules
 */
static inline unsigned int smk_ptrace_mode(unsigned int mode)
{
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	if (mode & PTRACE_MODE_ATTACH)
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		return MAY_READWRITE;
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	if (mode & PTRACE_MODE_READ)
		return MAY_READ;
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	return 0;
}

/**
 * smk_ptrace_rule_check - helper for ptrace access
 * @tracer: tracer process
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 * @tracee_known: label entry of the process that's about to be traced
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 * @mode: ptrace attachment mode (PTRACE_MODE_*)
 * @func: name of the function that called us, used for audit
 *
 * Returns 0 on access granted, -error on error
 */
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static int smk_ptrace_rule_check(struct task_struct *tracer,
				 struct smack_known *tracee_known,
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				 unsigned int mode, const char *func)
{
	int rc;
	struct smk_audit_info ad, *saip = NULL;
	struct task_smack *tsp;
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	struct smack_known *tracer_known;
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	const struct cred *tracercred;
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	if ((mode & PTRACE_MODE_NOAUDIT) == 0) {
		smk_ad_init(&ad, func, LSM_AUDIT_DATA_TASK);
		smk_ad_setfield_u_tsk(&ad, tracer);
		saip = &ad;
	}

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	rcu_read_lock();
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	tracercred = __task_cred(tracer);
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	tsp = smack_cred(tracercred);
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	tracer_known = smk_of_task(tsp);
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	if ((mode & PTRACE_MODE_ATTACH) &&
	    (smack_ptrace_rule == SMACK_PTRACE_EXACT ||
	     smack_ptrace_rule == SMACK_PTRACE_DRACONIAN)) {
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		if (tracer_known->smk_known == tracee_known->smk_known)
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			rc = 0;
		else if (smack_ptrace_rule == SMACK_PTRACE_DRACONIAN)
			rc = -EACCES;
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		else if (smack_privileged_cred(CAP_SYS_PTRACE, tracercred))
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			rc = 0;
		else
			rc = -EACCES;

		if (saip)
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			smack_log(tracer_known->smk_known,
				  tracee_known->smk_known,
				  0, rc, saip);
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		rcu_read_unlock();
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		return rc;
	}

	/* In case of rule==SMACK_PTRACE_DEFAULT or mode==PTRACE_MODE_READ */
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	rc = smk_tskacc(tsp, tracee_known, smk_ptrace_mode(mode), saip);
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	rcu_read_unlock();
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	return rc;
}

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/*
 * LSM hooks.
 * We he, that is fun!
 */

/**
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 * smack_ptrace_access_check - Smack approval on PTRACE_ATTACH
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 * @ctp: child task pointer
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 * @mode: ptrace attachment mode (PTRACE_MODE_*)
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 *
 * Returns 0 if access is OK, an error code otherwise
 *
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 * Do the capability checks.
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 */
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static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode)
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{
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	struct smack_known *skp;
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	skp = smk_of_task_struct(ctp);
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	return smk_ptrace_rule_check(current, skp, mode, __func__);
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}

/**
 * smack_ptrace_traceme - Smack approval on PTRACE_TRACEME
 * @ptp: parent task pointer
 *
 * Returns 0 if access is OK, an error code otherwise
 *
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 * Do the capability checks, and require PTRACE_MODE_ATTACH.
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 */
static int smack_ptrace_traceme(struct task_struct *ptp)
{
	int rc;
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	struct smack_known *skp;
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	skp = smk_of_task(smack_cred(current_cred()));
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	rc = smk_ptrace_rule_check(ptp, skp, PTRACE_MODE_ATTACH, __func__);
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	return rc;
}

/**
 * smack_syslog - Smack approval on syslog
 * @type: message type
 *
 * Returns 0 on success, error code otherwise.
 */
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static int smack_syslog(int typefrom_file)
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{
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	int rc = 0;
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	struct smack_known *skp = smk_of_current();
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	if (smack_privileged(CAP_MAC_OVERRIDE))
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		return 0;

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	if (smack_syslog_label != NULL && smack_syslog_label != skp)
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		rc = -EACCES;

	return rc;
}

/*
 * Superblock Hooks.
 */

/**
 * smack_sb_alloc_security - allocate a superblock blob
 * @sb: the superblock getting the blob
 *
 * Returns 0 on success or -ENOMEM on error.
 */
static int smack_sb_alloc_security(struct super_block *sb)
{
	struct superblock_smack *sbsp;

	sbsp = kzalloc(sizeof(struct superblock_smack), GFP_KERNEL);

	if (sbsp == NULL)
		return -ENOMEM;

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	sbsp->smk_root = &smack_known_floor;
	sbsp->smk_default = &smack_known_floor;
	sbsp->smk_floor = &smack_known_floor;
	sbsp->smk_hat = &smack_known_hat;
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	/*
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	 * SMK_SB_INITIALIZED will be zero from kzalloc.
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	 */
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	sb->s_security = sbsp;

	return 0;
}

/**
 * smack_sb_free_security - free a superblock blob
 * @sb: the superblock getting the blob
 *
 */
static void smack_sb_free_security(struct super_block *sb)
{
	kfree(sb->s_security);
	sb->s_security = NULL;
}

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struct smack_mnt_opts {
	const char *fsdefault, *fsfloor, *fshat, *fsroot, *fstransmute;
};
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static void smack_free_mnt_opts(void *mnt_opts)
{
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	struct smack_mnt_opts *opts = mnt_opts;
	kfree(opts->fsdefault);
	kfree(opts->fsfloor);
	kfree(opts->fshat);
	kfree(opts->fsroot);
	kfree(opts->fstransmute);
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	kfree(opts);
}
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static int smack_add_opt(int token, const char *s, void **mnt_opts)
{
	struct smack_mnt_opts *opts = *mnt_opts;
592

593 594 595 596 597
	if (!opts) {
		opts = kzalloc(sizeof(struct smack_mnt_opts), GFP_KERNEL);
		if (!opts)
			return -ENOMEM;
		*mnt_opts = opts;
598
	}
599 600
	if (!s)
		return -ENOMEM;
601

602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628
	switch (token) {
	case Opt_fsdefault:
		if (opts->fsdefault)
			goto out_opt_err;
		opts->fsdefault = s;
		break;
	case Opt_fsfloor:
		if (opts->fsfloor)
			goto out_opt_err;
		opts->fsfloor = s;
		break;
	case Opt_fshat:
		if (opts->fshat)
			goto out_opt_err;
		opts->fshat = s;
		break;
	case Opt_fsroot:
		if (opts->fsroot)
			goto out_opt_err;
		opts->fsroot = s;
		break;
	case Opt_fstransmute:
		if (opts->fstransmute)
			goto out_opt_err;
		opts->fstransmute = s;
		break;
	}
629
	return 0;
630 631 632 633

out_opt_err:
	pr_warn("Smack: duplicate mount options\n");
	return -EINVAL;
634 635
}

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Al Viro 已提交
636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683
/**
 * smack_fs_context_dup - Duplicate the security data on fs_context duplication
 * @fc: The new filesystem context.
 * @src_fc: The source filesystem context being duplicated.
 *
 * Returns 0 on success or -ENOMEM on error.
 */
static int smack_fs_context_dup(struct fs_context *fc,
				struct fs_context *src_fc)
{
	struct smack_mnt_opts *dst, *src = src_fc->security;

	if (!src)
		return 0;

	fc->security = kzalloc(sizeof(struct smack_mnt_opts), GFP_KERNEL);
	if (!fc->security)
		return -ENOMEM;
	dst = fc->security;

	if (src->fsdefault) {
		dst->fsdefault = kstrdup(src->fsdefault, GFP_KERNEL);
		if (!dst->fsdefault)
			return -ENOMEM;
	}
	if (src->fsfloor) {
		dst->fsfloor = kstrdup(src->fsfloor, GFP_KERNEL);
		if (!dst->fsfloor)
			return -ENOMEM;
	}
	if (src->fshat) {
		dst->fshat = kstrdup(src->fshat, GFP_KERNEL);
		if (!dst->fshat)
			return -ENOMEM;
	}
	if (src->fsroot) {
		dst->fsroot = kstrdup(src->fsroot, GFP_KERNEL);
		if (!dst->fsroot)
			return -ENOMEM;
	}
	if (src->fstransmute) {
		dst->fstransmute = kstrdup(src->fstransmute, GFP_KERNEL);
		if (!dst->fstransmute)
			return -ENOMEM;
	}
	return 0;
}

684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721
static const struct fs_parameter_spec smack_param_specs[] = {
	fsparam_string("fsdefault",	Opt_fsdefault),
	fsparam_string("fsfloor",	Opt_fsfloor),
	fsparam_string("fshat",		Opt_fshat),
	fsparam_string("fsroot",	Opt_fsroot),
	fsparam_string("fstransmute",	Opt_fstransmute),
	{}
};

static const struct fs_parameter_description smack_fs_parameters = {
	.name		= "smack",
	.specs		= smack_param_specs,
};

/**
 * smack_fs_context_parse_param - Parse a single mount parameter
 * @fc: The new filesystem context being constructed.
 * @param: The parameter.
 *
 * Returns 0 on success, -ENOPARAM to pass the parameter on or anything else on
 * error.
 */
static int smack_fs_context_parse_param(struct fs_context *fc,
					struct fs_parameter *param)
{
	struct fs_parse_result result;
	int opt, rc;

	opt = fs_parse(fc, &smack_fs_parameters, param, &result);
	if (opt < 0)
		return opt;

	rc = smack_add_opt(opt, param->string, &fc->security);
	if (!rc)
		param->string = NULL;
	return rc;
}

A
Al Viro 已提交
722
static int smack_sb_eat_lsm_opts(char *options, void **mnt_opts)
723
{
A
Al Viro 已提交
724 725
	char *from = options, *to = options;
	bool first = true;
726

A
Al Viro 已提交
727 728 729 730
	while (1) {
		char *next = strchr(from, ',');
		int token, len, rc;
		char *arg = NULL;
731

A
Al Viro 已提交
732 733 734 735
		if (next)
			len = next - from;
		else
			len = strlen(from);
736

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Al Viro 已提交
737
		token = match_opt_prefix(from, len, &arg);
A
Al Viro 已提交
738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756
		if (token != Opt_error) {
			arg = kmemdup_nul(arg, from + len - arg, GFP_KERNEL);
			rc = smack_add_opt(token, arg, mnt_opts);
			if (unlikely(rc)) {
				kfree(arg);
				if (*mnt_opts)
					smack_free_mnt_opts(*mnt_opts);
				*mnt_opts = NULL;
				return rc;
			}
		} else {
			if (!first) {	// copy with preceding comma
				from--;
				len++;
			}
			if (to != from)
				memmove(to, from, len);
			to += len;
			first = false;
757
		}
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Al Viro 已提交
758 759 760
		if (!from[len])
			break;
		from += len + 1;
761
	}
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762
	*to = '\0';
763 764 765 766 767
	return 0;
}

/**
 * smack_set_mnt_opts - set Smack specific mount options
768
 * @sb: the file system superblock
769 770 771
 * @opts: Smack mount options
 * @kern_flags: mount option from kernel space or user space
 * @set_kern_flags: where to store converted mount opts
772 773
 *
 * Returns 0 on success, an error code on failure
774 775 776
 *
 * Allow filesystems with binary mount data to explicitly set Smack mount
 * labels.
777
 */
778
static int smack_set_mnt_opts(struct super_block *sb,
779
		void *mnt_opts,
780 781
		unsigned long kern_flags,
		unsigned long *set_kern_flags)
782 783
{
	struct dentry *root = sb->s_root;
784
	struct inode *inode = d_backing_inode(root);
785 786
	struct superblock_smack *sp = sb->s_security;
	struct inode_smack *isp;
787
	struct smack_known *skp;
A
Al Viro 已提交
788 789
	struct smack_mnt_opts *opts = mnt_opts;
	bool transmute = false;
790

791
	if (sp->smk_flags & SMK_SB_INITIALIZED)
792
		return 0;
793

794 795 796 797 798 799 800
	if (inode->i_security == NULL) {
		int rc = lsm_inode_alloc(inode);

		if (rc)
			return rc;
	}

801 802 803 804
	if (!smack_privileged(CAP_MAC_ADMIN)) {
		/*
		 * Unprivileged mounts don't get to specify Smack values.
		 */
A
Al Viro 已提交
805
		if (opts)
806 807 808 809 810 811 812 813 814 815 816 817 818 819 820
			return -EPERM;
		/*
		 * Unprivileged mounts get root and default from the caller.
		 */
		skp = smk_of_current();
		sp->smk_root = skp;
		sp->smk_default = skp;
		/*
		 * For a handful of fs types with no user-controlled
		 * backing store it's okay to trust security labels
		 * in the filesystem. The rest are untrusted.
		 */
		if (sb->s_user_ns != &init_user_ns &&
		    sb->s_magic != SYSFS_MAGIC && sb->s_magic != TMPFS_MAGIC &&
		    sb->s_magic != RAMFS_MAGIC) {
A
Al Viro 已提交
821
			transmute = true;
822 823 824 825
			sp->smk_flags |= SMK_SB_UNTRUSTED;
		}
	}

826
	sp->smk_flags |= SMK_SB_INITIALIZED;
827

A
Al Viro 已提交
828 829 830
	if (opts) {
		if (opts->fsdefault) {
			skp = smk_import_entry(opts->fsdefault, 0);
831 832
			if (IS_ERR(skp))
				return PTR_ERR(skp);
833
			sp->smk_default = skp;
A
Al Viro 已提交
834 835 836
		}
		if (opts->fsfloor) {
			skp = smk_import_entry(opts->fsfloor, 0);
837 838 839
			if (IS_ERR(skp))
				return PTR_ERR(skp);
			sp->smk_floor = skp;
A
Al Viro 已提交
840 841 842
		}
		if (opts->fshat) {
			skp = smk_import_entry(opts->fshat, 0);
843 844
			if (IS_ERR(skp))
				return PTR_ERR(skp);
845
			sp->smk_hat = skp;
A
Al Viro 已提交
846 847 848
		}
		if (opts->fsroot) {
			skp = smk_import_entry(opts->fsroot, 0);
849 850 851
			if (IS_ERR(skp))
				return PTR_ERR(skp);
			sp->smk_root = skp;
A
Al Viro 已提交
852 853 854
		}
		if (opts->fstransmute) {
			skp = smk_import_entry(opts->fstransmute, 0);
855 856 857
			if (IS_ERR(skp))
				return PTR_ERR(skp);
			sp->smk_root = skp;
A
Al Viro 已提交
858
			transmute = true;
859 860 861 862 863 864
		}
	}

	/*
	 * Initialize the root inode.
	 */
865
	init_inode_smack(inode, sp->smk_root);
866

867 868
	if (transmute) {
		isp = smack_inode(inode);
869
		isp->smk_flags |= SMK_INODE_TRANSMUTE;
870
	}
871

872 873 874 875 876 877 878 879 880 881 882 883 884
	return 0;
}

/**
 * smack_sb_statfs - Smack check on statfs
 * @dentry: identifies the file system in question
 *
 * Returns 0 if current can read the floor of the filesystem,
 * and error code otherwise
 */
static int smack_sb_statfs(struct dentry *dentry)
{
	struct superblock_smack *sbp = dentry->d_sb->s_security;
E
Etienne Basset 已提交
885 886 887
	int rc;
	struct smk_audit_info ad;

888
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
E
Etienne Basset 已提交
889
	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
890

E
Etienne Basset 已提交
891
	rc = smk_curacc(sbp->smk_floor, MAY_READ, &ad);
C
Casey Schaufler 已提交
892
	rc = smk_bu_current("statfs", sbp->smk_floor, MAY_READ, rc);
E
Etienne Basset 已提交
893
	return rc;
894 895
}

896 897 898 899
/*
 * BPRM hooks
 */

C
Casey Schaufler 已提交
900 901 902 903
/**
 * smack_bprm_set_creds - set creds for exec
 * @bprm: the exec information
 *
904
 * Returns 0 if it gets a blob, -EPERM if exec forbidden and -ENOMEM otherwise
C
Casey Schaufler 已提交
905
 */
906 907
static int smack_bprm_set_creds(struct linux_binprm *bprm)
{
A
Al Viro 已提交
908
	struct inode *inode = file_inode(bprm->file);
909
	struct task_smack *bsp = smack_cred(bprm->cred);
910
	struct inode_smack *isp;
911
	struct superblock_smack *sbsp;
912 913
	int rc;

914
	if (bprm->called_set_creds)
915 916
		return 0;

917
	isp = smack_inode(inode);
918
	if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task)
919 920
		return 0;

921 922 923 924 925
	sbsp = inode->i_sb->s_security;
	if ((sbsp->smk_flags & SMK_SB_UNTRUSTED) &&
	    isp->smk_task != sbsp->smk_root)
		return 0;

926
	if (bprm->unsafe & LSM_UNSAFE_PTRACE) {
927 928 929 930 931 932 933
		struct task_struct *tracer;
		rc = 0;

		rcu_read_lock();
		tracer = ptrace_parent(current);
		if (likely(tracer != NULL))
			rc = smk_ptrace_rule_check(tracer,
934
						   isp->smk_task,
935 936 937 938 939 940 941
						   PTRACE_MODE_ATTACH,
						   __func__);
		rcu_read_unlock();

		if (rc != 0)
			return rc;
	} else if (bprm->unsafe)
942
		return -EPERM;
943

944 945
	bsp->smk_task = isp->smk_task;
	bprm->per_clear |= PER_CLEAR_ON_SETID;
946

947 948 949 950
	/* Decide if this is a secure exec. */
	if (bsp->smk_task != bsp->smk_forked)
		bprm->secureexec = 1;

951 952
	return 0;
}
953

954 955 956 957 958 959
/*
 * Inode hooks
 */

/**
 * smack_inode_alloc_security - allocate an inode blob
960
 * @inode: the inode in need of a blob
961 962 963 964 965
 *
 * Returns 0 if it gets a blob, -ENOMEM otherwise
 */
static int smack_inode_alloc_security(struct inode *inode)
{
966 967
	struct smack_known *skp = smk_of_current();

968
	init_inode_smack(inode, skp);
969 970 971 972 973
	return 0;
}

/**
 * smack_inode_init_security - copy out the smack from an inode
974 975
 * @inode: the newly created inode
 * @dir: containing directory object
976
 * @qstr: unused
977 978 979 980 981 982 983
 * @name: where to put the attribute name
 * @value: where to put the attribute value
 * @len: where to put the length of the attribute
 *
 * Returns 0 if it all works out, -ENOMEM if there's no memory
 */
static int smack_inode_init_security(struct inode *inode, struct inode *dir,
984
				     const struct qstr *qstr, const char **name,
985
				     void **value, size_t *len)
986
{
987
	struct inode_smack *issp = smack_inode(inode);
988
	struct smack_known *skp = smk_of_current();
989 990
	struct smack_known *isp = smk_of_inode(inode);
	struct smack_known *dsp = smk_of_inode(dir);
991
	int may;
992

993 994
	if (name)
		*name = XATTR_SMACK_SUFFIX;
995

996
	if (value && len) {
997
		rcu_read_lock();
998 999
		may = smk_access_entry(skp->smk_known, dsp->smk_known,
				       &skp->smk_rules);
1000
		rcu_read_unlock();
1001 1002 1003 1004 1005

		/*
		 * If the access rule allows transmutation and
		 * the directory requests transmutation then
		 * by all means transmute.
C
Casey Schaufler 已提交
1006
		 * Mark the inode as changed.
1007
		 */
1008
		if (may > 0 && ((may & MAY_TRANSMUTE) != 0) &&
C
Casey Schaufler 已提交
1009
		    smk_inode_transmutable(dir)) {
1010
			isp = dsp;
C
Casey Schaufler 已提交
1011 1012
			issp->smk_flags |= SMK_INODE_CHANGED;
		}
1013

1014
		*value = kstrdup(isp->smk_known, GFP_NOFS);
1015 1016 1017
		if (*value == NULL)
			return -ENOMEM;

1018
		*len = strlen(isp->smk_known);
1019
	}
1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034

	return 0;
}

/**
 * smack_inode_link - Smack check on link
 * @old_dentry: the existing object
 * @dir: unused
 * @new_dentry: the new object
 *
 * Returns 0 if access is permitted, an error code otherwise
 */
static int smack_inode_link(struct dentry *old_dentry, struct inode *dir,
			    struct dentry *new_dentry)
{
1035
	struct smack_known *isp;
E
Etienne Basset 已提交
1036 1037 1038
	struct smk_audit_info ad;
	int rc;

1039
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
E
Etienne Basset 已提交
1040
	smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
1041

1042
	isp = smk_of_inode(d_backing_inode(old_dentry));
E
Etienne Basset 已提交
1043
	rc = smk_curacc(isp, MAY_WRITE, &ad);
1044
	rc = smk_bu_inode(d_backing_inode(old_dentry), MAY_WRITE, rc);
1045

1046
	if (rc == 0 && d_is_positive(new_dentry)) {
1047
		isp = smk_of_inode(d_backing_inode(new_dentry));
E
Etienne Basset 已提交
1048 1049
		smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
		rc = smk_curacc(isp, MAY_WRITE, &ad);
1050
		rc = smk_bu_inode(d_backing_inode(new_dentry), MAY_WRITE, rc);
1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065
	}

	return rc;
}

/**
 * smack_inode_unlink - Smack check on inode deletion
 * @dir: containing directory object
 * @dentry: file to unlink
 *
 * Returns 0 if current can write the containing directory
 * and the object, error code otherwise
 */
static int smack_inode_unlink(struct inode *dir, struct dentry *dentry)
{
1066
	struct inode *ip = d_backing_inode(dentry);
E
Etienne Basset 已提交
1067
	struct smk_audit_info ad;
1068 1069
	int rc;

1070
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
E
Etienne Basset 已提交
1071 1072
	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);

1073 1074 1075
	/*
	 * You need write access to the thing you're unlinking
	 */
E
Etienne Basset 已提交
1076
	rc = smk_curacc(smk_of_inode(ip), MAY_WRITE, &ad);
C
Casey Schaufler 已提交
1077
	rc = smk_bu_inode(ip, MAY_WRITE, rc);
E
Etienne Basset 已提交
1078
	if (rc == 0) {
1079 1080 1081
		/*
		 * You also need write access to the containing directory
		 */
1082
		smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
E
Etienne Basset 已提交
1083 1084
		smk_ad_setfield_u_fs_inode(&ad, dir);
		rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
C
Casey Schaufler 已提交
1085
		rc = smk_bu_inode(dir, MAY_WRITE, rc);
E
Etienne Basset 已提交
1086
	}
1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099
	return rc;
}

/**
 * smack_inode_rmdir - Smack check on directory deletion
 * @dir: containing directory object
 * @dentry: directory to unlink
 *
 * Returns 0 if current can write the containing directory
 * and the directory, error code otherwise
 */
static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry)
{
E
Etienne Basset 已提交
1100
	struct smk_audit_info ad;
1101 1102
	int rc;

1103
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
E
Etienne Basset 已提交
1104 1105
	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);

1106 1107 1108
	/*
	 * You need write access to the thing you're removing
	 */
1109 1110
	rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
	rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
E
Etienne Basset 已提交
1111
	if (rc == 0) {
1112 1113 1114
		/*
		 * You also need write access to the containing directory
		 */
1115
		smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
E
Etienne Basset 已提交
1116 1117
		smk_ad_setfield_u_fs_inode(&ad, dir);
		rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
C
Casey Schaufler 已提交
1118
		rc = smk_bu_inode(dir, MAY_WRITE, rc);
E
Etienne Basset 已提交
1119
	}
1120 1121 1122 1123 1124 1125

	return rc;
}

/**
 * smack_inode_rename - Smack check on rename
1126 1127 1128 1129
 * @old_inode: unused
 * @old_dentry: the old object
 * @new_inode: unused
 * @new_dentry: the new object
1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141
 *
 * Read and write access is required on both the old and
 * new directories.
 *
 * Returns 0 if access is permitted, an error code otherwise
 */
static int smack_inode_rename(struct inode *old_inode,
			      struct dentry *old_dentry,
			      struct inode *new_inode,
			      struct dentry *new_dentry)
{
	int rc;
1142
	struct smack_known *isp;
E
Etienne Basset 已提交
1143 1144
	struct smk_audit_info ad;

1145
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
E
Etienne Basset 已提交
1146
	smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
1147

1148
	isp = smk_of_inode(d_backing_inode(old_dentry));
E
Etienne Basset 已提交
1149
	rc = smk_curacc(isp, MAY_READWRITE, &ad);
1150
	rc = smk_bu_inode(d_backing_inode(old_dentry), MAY_READWRITE, rc);
1151

1152
	if (rc == 0 && d_is_positive(new_dentry)) {
1153
		isp = smk_of_inode(d_backing_inode(new_dentry));
E
Etienne Basset 已提交
1154 1155
		smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
		rc = smk_curacc(isp, MAY_READWRITE, &ad);
1156
		rc = smk_bu_inode(d_backing_inode(new_dentry), MAY_READWRITE, rc);
1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169
	}
	return rc;
}

/**
 * smack_inode_permission - Smack version of permission()
 * @inode: the inode in question
 * @mask: the access requested
 *
 * This is the important Smack hook.
 *
 * Returns 0 if access is permitted, -EACCES otherwise
 */
1170
static int smack_inode_permission(struct inode *inode, int mask)
1171
{
1172
	struct superblock_smack *sbsp = inode->i_sb->s_security;
E
Etienne Basset 已提交
1173
	struct smk_audit_info ad;
1174
	int no_block = mask & MAY_NOT_BLOCK;
C
Casey Schaufler 已提交
1175
	int rc;
1176 1177

	mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
1178 1179 1180 1181 1182
	/*
	 * No permission to check. Existence test. Yup, it's there.
	 */
	if (mask == 0)
		return 0;
1183

1184 1185 1186 1187 1188
	if (sbsp->smk_flags & SMK_SB_UNTRUSTED) {
		if (smk_of_inode(inode) != sbsp->smk_root)
			return -EACCES;
	}

1189
	/* May be droppable after audit */
1190
	if (no_block)
1191
		return -ECHILD;
1192
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
E
Etienne Basset 已提交
1193
	smk_ad_setfield_u_fs_inode(&ad, inode);
C
Casey Schaufler 已提交
1194 1195 1196
	rc = smk_curacc(smk_of_inode(inode), mask, &ad);
	rc = smk_bu_inode(inode, mask, rc);
	return rc;
1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207
}

/**
 * smack_inode_setattr - Smack check for setting attributes
 * @dentry: the object
 * @iattr: for the force flag
 *
 * Returns 0 if access is permitted, an error code otherwise
 */
static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr)
{
E
Etienne Basset 已提交
1208
	struct smk_audit_info ad;
C
Casey Schaufler 已提交
1209 1210
	int rc;

1211 1212 1213 1214 1215
	/*
	 * Need to allow for clearing the setuid bit.
	 */
	if (iattr->ia_valid & ATTR_FORCE)
		return 0;
1216
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
E
Etienne Basset 已提交
1217
	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1218

1219 1220
	rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
	rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
C
Casey Schaufler 已提交
1221
	return rc;
1222 1223 1224 1225
}

/**
 * smack_inode_getattr - Smack check for getting attributes
1226
 * @mnt: vfsmount of the object
1227 1228 1229 1230
 * @dentry: the object
 *
 * Returns 0 if access is permitted, an error code otherwise
 */
1231
static int smack_inode_getattr(const struct path *path)
1232
{
E
Etienne Basset 已提交
1233
	struct smk_audit_info ad;
1234
	struct inode *inode = d_backing_inode(path->dentry);
C
Casey Schaufler 已提交
1235
	int rc;
E
Etienne Basset 已提交
1236

1237
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1238 1239 1240
	smk_ad_setfield_u_fs_path(&ad, *path);
	rc = smk_curacc(smk_of_inode(inode), MAY_READ, &ad);
	rc = smk_bu_inode(inode, MAY_READ, rc);
C
Casey Schaufler 已提交
1241
	return rc;
1242 1243 1244 1245 1246 1247
}

/**
 * smack_inode_setxattr - Smack check for setting xattrs
 * @dentry: the object
 * @name: name of the attribute
1248 1249
 * @value: value of the attribute
 * @size: size of the value
1250 1251 1252 1253 1254 1255
 * @flags: unused
 *
 * This protects the Smack attribute explicitly.
 *
 * Returns 0 if access is permitted, an error code otherwise
 */
1256 1257
static int smack_inode_setxattr(struct dentry *dentry, const char *name,
				const void *value, size_t size, int flags)
1258
{
E
Etienne Basset 已提交
1259
	struct smk_audit_info ad;
1260 1261 1262 1263
	struct smack_known *skp;
	int check_priv = 0;
	int check_import = 0;
	int check_star = 0;
1264
	int rc = 0;
1265

1266 1267 1268
	/*
	 * Check label validity here so import won't fail in post_setxattr
	 */
1269 1270
	if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
	    strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
1271 1272 1273 1274 1275 1276 1277 1278
	    strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) {
		check_priv = 1;
		check_import = 1;
	} else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
		   strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
		check_priv = 1;
		check_import = 1;
		check_star = 1;
1279
	} else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
1280
		check_priv = 1;
1281 1282 1283
		if (size != TRANS_TRUE_SIZE ||
		    strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0)
			rc = -EINVAL;
1284 1285 1286
	} else
		rc = cap_inode_setxattr(dentry, name, value, size, flags);

1287 1288 1289 1290
	if (check_priv && !smack_privileged(CAP_MAC_ADMIN))
		rc = -EPERM;

	if (rc == 0 && check_import) {
1291
		skp = size ? smk_import_entry(value, size) : NULL;
1292 1293 1294
		if (IS_ERR(skp))
			rc = PTR_ERR(skp);
		else if (skp == NULL || (check_star &&
1295 1296 1297 1298
		    (skp == &smack_known_star || skp == &smack_known_web)))
			rc = -EINVAL;
	}

1299
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
E
Etienne Basset 已提交
1300 1301
	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);

C
Casey Schaufler 已提交
1302
	if (rc == 0) {
1303 1304
		rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
		rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
C
Casey Schaufler 已提交
1305
	}
1306 1307

	return rc;
1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320
}

/**
 * smack_inode_post_setxattr - Apply the Smack update approved above
 * @dentry: object
 * @name: attribute name
 * @value: attribute value
 * @size: attribute size
 * @flags: unused
 *
 * Set the pointer in the inode blob to the entry found
 * in the master label list.
 */
1321 1322
static void smack_inode_post_setxattr(struct dentry *dentry, const char *name,
				      const void *value, size_t size, int flags)
1323
{
1324
	struct smack_known *skp;
1325
	struct inode_smack *isp = smack_inode(d_backing_inode(dentry));
1326

1327 1328 1329 1330 1331
	if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
		isp->smk_flags |= SMK_INODE_TRANSMUTE;
		return;
	}

1332
	if (strcmp(name, XATTR_NAME_SMACK) == 0) {
1333
		skp = smk_import_entry(value, size);
1334
		if (!IS_ERR(skp))
1335
			isp->smk_inode = skp;
1336
	} else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) {
1337
		skp = smk_import_entry(value, size);
1338
		if (!IS_ERR(skp))
1339
			isp->smk_task = skp;
1340
	} else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
1341
		skp = smk_import_entry(value, size);
1342
		if (!IS_ERR(skp))
1343 1344
			isp->smk_mmap = skp;
	}
1345 1346 1347 1348

	return;
}

C
Casey Schaufler 已提交
1349
/**
1350 1351 1352 1353 1354 1355
 * smack_inode_getxattr - Smack check on getxattr
 * @dentry: the object
 * @name: unused
 *
 * Returns 0 if access is permitted, an error code otherwise
 */
1356
static int smack_inode_getxattr(struct dentry *dentry, const char *name)
1357
{
E
Etienne Basset 已提交
1358
	struct smk_audit_info ad;
C
Casey Schaufler 已提交
1359
	int rc;
E
Etienne Basset 已提交
1360

1361
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
E
Etienne Basset 已提交
1362 1363
	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);

1364 1365
	rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_READ, &ad);
	rc = smk_bu_inode(d_backing_inode(dentry), MAY_READ, rc);
C
Casey Schaufler 已提交
1366
	return rc;
1367 1368
}

C
Casey Schaufler 已提交
1369
/**
1370 1371 1372 1373 1374 1375 1376 1377
 * smack_inode_removexattr - Smack check on removexattr
 * @dentry: the object
 * @name: name of the attribute
 *
 * Removing the Smack attribute requires CAP_MAC_ADMIN
 *
 * Returns 0 if access is permitted, an error code otherwise
 */
1378
static int smack_inode_removexattr(struct dentry *dentry, const char *name)
1379
{
1380
	struct inode_smack *isp;
E
Etienne Basset 已提交
1381
	struct smk_audit_info ad;
1382
	int rc = 0;
1383

1384 1385
	if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
	    strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
1386
	    strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 ||
1387
	    strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
1388
	    strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0 ||
P
Pankaj Kumar 已提交
1389
	    strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
1390
		if (!smack_privileged(CAP_MAC_ADMIN))
1391 1392 1393 1394
			rc = -EPERM;
	} else
		rc = cap_inode_removexattr(dentry, name);

1395 1396 1397
	if (rc != 0)
		return rc;

1398
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
E
Etienne Basset 已提交
1399
	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1400

1401 1402
	rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
	rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
1403 1404 1405
	if (rc != 0)
		return rc;

1406
	isp = smack_inode(d_backing_inode(dentry));
1407 1408 1409 1410 1411
	/*
	 * Don't do anything special for these.
	 *	XATTR_NAME_SMACKIPIN
	 *	XATTR_NAME_SMACKIPOUT
	 */
J
José Bollo 已提交
1412
	if (strcmp(name, XATTR_NAME_SMACK) == 0) {
1413
		struct super_block *sbp = dentry->d_sb;
J
José Bollo 已提交
1414 1415 1416 1417
		struct superblock_smack *sbsp = sbp->s_security;

		isp->smk_inode = sbsp->smk_default;
	} else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0)
1418
		isp->smk_task = NULL;
1419
	else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0)
1420
		isp->smk_mmap = NULL;
1421 1422
	else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0)
		isp->smk_flags &= ~SMK_INODE_TRANSMUTE;
1423

1424
	return 0;
1425 1426 1427 1428 1429 1430 1431
}

/**
 * smack_inode_getsecurity - get smack xattrs
 * @inode: the object
 * @name: attribute name
 * @buffer: where to put the result
1432
 * @alloc: duplicate memory
1433 1434 1435
 *
 * Returns the size of the attribute or an error code
 */
1436
static int smack_inode_getsecurity(struct inode *inode,
1437 1438 1439 1440 1441 1442 1443
				   const char *name, void **buffer,
				   bool alloc)
{
	struct socket_smack *ssp;
	struct socket *sock;
	struct super_block *sbp;
	struct inode *ip = (struct inode *)inode;
1444
	struct smack_known *isp;
1445

1446
	if (strcmp(name, XATTR_SMACK_SUFFIX) == 0)
1447
		isp = smk_of_inode(inode);
1448 1449 1450 1451 1452 1453 1454
	else {
		/*
		 * The rest of the Smack xattrs are only on sockets.
		 */
		sbp = ip->i_sb;
		if (sbp->s_magic != SOCKFS_MAGIC)
			return -EOPNOTSUPP;
1455

1456 1457 1458
		sock = SOCKET_I(ip);
		if (sock == NULL || sock->sk == NULL)
			return -EOPNOTSUPP;
1459

1460
		ssp = sock->sk->sk_security;
1461

1462 1463 1464 1465 1466 1467 1468
		if (strcmp(name, XATTR_SMACK_IPIN) == 0)
			isp = ssp->smk_in;
		else if (strcmp(name, XATTR_SMACK_IPOUT) == 0)
			isp = ssp->smk_out;
		else
			return -EOPNOTSUPP;
	}
1469

1470 1471 1472 1473
	if (alloc) {
		*buffer = kstrdup(isp->smk_known, GFP_KERNEL);
		if (*buffer == NULL)
			return -ENOMEM;
1474 1475
	}

1476
	return strlen(isp->smk_known);
1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488
}


/**
 * smack_inode_listsecurity - list the Smack attributes
 * @inode: the object
 * @buffer: where they go
 * @buffer_size: size of buffer
 */
static int smack_inode_listsecurity(struct inode *inode, char *buffer,
				    size_t buffer_size)
{
1489
	int len = sizeof(XATTR_NAME_SMACK);
1490

1491
	if (buffer != NULL && len <= buffer_size)
1492
		memcpy(buffer, XATTR_NAME_SMACK, len);
1493 1494

	return len;
1495 1496
}

1497 1498 1499 1500 1501
/**
 * smack_inode_getsecid - Extract inode's security id
 * @inode: inode to extract the info from
 * @secid: where result will be saved
 */
1502
static void smack_inode_getsecid(struct inode *inode, u32 *secid)
1503
{
1504
	struct smack_known *skp = smk_of_inode(inode);
1505

1506
	*secid = skp->smk_secid;
1507 1508
}

1509 1510 1511 1512
/*
 * File Hooks
 */

C
Casey Schaufler 已提交
1513 1514
/*
 * There is no smack_file_permission hook
1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530
 *
 * Should access checks be done on each read or write?
 * UNICOS and SELinux say yes.
 * Trusted Solaris, Trusted Irix, and just about everyone else says no.
 *
 * I'll say no for now. Smack does not do the frequent
 * label changing that SELinux does.
 */

/**
 * smack_file_alloc_security - assign a file security blob
 * @file: the object
 *
 * The security blob for a file is a pointer to the master
 * label list, so no allocation is done.
 *
C
Casey Schaufler 已提交
1531 1532 1533
 * f_security is the owner security information. It
 * isn't used on file access checks, it's for send_sigio.
 *
1534 1535 1536 1537
 * Returns 0
 */
static int smack_file_alloc_security(struct file *file)
{
1538
	struct smack_known **blob = smack_file(file);
1539

1540
	*blob = smk_of_current();
1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557
	return 0;
}

/**
 * smack_file_ioctl - Smack check on ioctls
 * @file: the object
 * @cmd: what to do
 * @arg: unused
 *
 * Relies heavily on the correct use of the ioctl command conventions.
 *
 * Returns 0 if allowed, error code otherwise
 */
static int smack_file_ioctl(struct file *file, unsigned int cmd,
			    unsigned long arg)
{
	int rc = 0;
E
Etienne Basset 已提交
1558
	struct smk_audit_info ad;
C
Casey Schaufler 已提交
1559
	struct inode *inode = file_inode(file);
E
Etienne Basset 已提交
1560

1561 1562 1563
	if (unlikely(IS_PRIVATE(inode)))
		return 0;

1564
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
E
Etienne Basset 已提交
1565
	smk_ad_setfield_u_fs_path(&ad, file->f_path);
1566

C
Casey Schaufler 已提交
1567
	if (_IOC_DIR(cmd) & _IOC_WRITE) {
C
Casey Schaufler 已提交
1568
		rc = smk_curacc(smk_of_inode(inode), MAY_WRITE, &ad);
C
Casey Schaufler 已提交
1569 1570
		rc = smk_bu_file(file, MAY_WRITE, rc);
	}
1571

C
Casey Schaufler 已提交
1572
	if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ)) {
C
Casey Schaufler 已提交
1573
		rc = smk_curacc(smk_of_inode(inode), MAY_READ, &ad);
C
Casey Schaufler 已提交
1574 1575
		rc = smk_bu_file(file, MAY_READ, rc);
	}
1576 1577 1578 1579 1580 1581 1582

	return rc;
}

/**
 * smack_file_lock - Smack check on file locking
 * @file: the object
1583
 * @cmd: unused
1584
 *
1585
 * Returns 0 if current has lock access, error code otherwise
1586 1587 1588
 */
static int smack_file_lock(struct file *file, unsigned int cmd)
{
E
Etienne Basset 已提交
1589
	struct smk_audit_info ad;
C
Casey Schaufler 已提交
1590
	int rc;
C
Casey Schaufler 已提交
1591
	struct inode *inode = file_inode(file);
E
Etienne Basset 已提交
1592

1593 1594 1595
	if (unlikely(IS_PRIVATE(inode)))
		return 0;

1596 1597
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
	smk_ad_setfield_u_fs_path(&ad, file->f_path);
C
Casey Schaufler 已提交
1598
	rc = smk_curacc(smk_of_inode(inode), MAY_LOCK, &ad);
C
Casey Schaufler 已提交
1599 1600
	rc = smk_bu_file(file, MAY_LOCK, rc);
	return rc;
1601 1602 1603 1604 1605 1606 1607 1608
}

/**
 * smack_file_fcntl - Smack check on fcntl
 * @file: the object
 * @cmd: what action to check
 * @arg: unused
 *
1609 1610 1611 1612
 * Generally these operations are harmless.
 * File locking operations present an obvious mechanism
 * for passing information, so they require write access.
 *
1613 1614 1615 1616 1617
 * Returns 0 if current has access, error code otherwise
 */
static int smack_file_fcntl(struct file *file, unsigned int cmd,
			    unsigned long arg)
{
E
Etienne Basset 已提交
1618
	struct smk_audit_info ad;
1619
	int rc = 0;
C
Casey Schaufler 已提交
1620
	struct inode *inode = file_inode(file);
E
Etienne Basset 已提交
1621

1622 1623 1624
	if (unlikely(IS_PRIVATE(inode)))
		return 0;

1625 1626
	switch (cmd) {
	case F_GETLK:
1627
		break;
1628 1629
	case F_SETLK:
	case F_SETLKW:
1630 1631
		smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
		smk_ad_setfield_u_fs_path(&ad, file->f_path);
C
Casey Schaufler 已提交
1632
		rc = smk_curacc(smk_of_inode(inode), MAY_LOCK, &ad);
C
Casey Schaufler 已提交
1633
		rc = smk_bu_file(file, MAY_LOCK, rc);
1634
		break;
1635 1636
	case F_SETOWN:
	case F_SETSIG:
1637 1638
		smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
		smk_ad_setfield_u_fs_path(&ad, file->f_path);
C
Casey Schaufler 已提交
1639
		rc = smk_curacc(smk_of_inode(inode), MAY_WRITE, &ad);
C
Casey Schaufler 已提交
1640
		rc = smk_bu_file(file, MAY_WRITE, rc);
1641 1642
		break;
	default:
1643
		break;
1644 1645 1646 1647 1648
	}

	return rc;
}

1649
/**
1650
 * smack_mmap_file :
1651 1652 1653 1654 1655 1656 1657 1658
 * Check permissions for a mmap operation.  The @file may be NULL, e.g.
 * if mapping anonymous memory.
 * @file contains the file structure for file to map (may be NULL).
 * @reqprot contains the protection requested by the application.
 * @prot contains the protection that will be applied by the kernel.
 * @flags contains the operational flags.
 * Return 0 if permission is granted.
 */
1659
static int smack_mmap_file(struct file *file,
1660
			   unsigned long reqprot, unsigned long prot,
1661
			   unsigned long flags)
1662
{
1663
	struct smack_known *skp;
1664
	struct smack_known *mkp;
1665 1666
	struct smack_rule *srp;
	struct task_smack *tsp;
1667
	struct smack_known *okp;
1668
	struct inode_smack *isp;
1669
	struct superblock_smack *sbsp;
1670 1671 1672
	int may;
	int mmay;
	int tmay;
1673 1674
	int rc;

A
Al Viro 已提交
1675
	if (file == NULL)
1676 1677
		return 0;

1678 1679 1680
	if (unlikely(IS_PRIVATE(file_inode(file))))
		return 0;

1681
	isp = smack_inode(file_inode(file));
1682 1683
	if (isp->smk_mmap == NULL)
		return 0;
1684 1685 1686 1687
	sbsp = file_inode(file)->i_sb->s_security;
	if (sbsp->smk_flags & SMK_SB_UNTRUSTED &&
	    isp->smk_mmap != sbsp->smk_root)
		return -EACCES;
1688
	mkp = isp->smk_mmap;
1689

1690
	tsp = smack_cred(current_cred());
1691
	skp = smk_of_current();
1692 1693 1694 1695 1696 1697 1698 1699
	rc = 0;

	rcu_read_lock();
	/*
	 * For each Smack rule associated with the subject
	 * label verify that the SMACK64MMAP also has access
	 * to that rule's object label.
	 */
1700
	list_for_each_entry_rcu(srp, &skp->smk_rules, list) {
1701
		okp = srp->smk_object;
1702 1703 1704
		/*
		 * Matching labels always allows access.
		 */
1705
		if (mkp->smk_known == okp->smk_known)
1706
			continue;
1707 1708 1709 1710
		/*
		 * If there is a matching local rule take
		 * that into account as well.
		 */
1711 1712 1713
		may = smk_access_entry(srp->smk_subject->smk_known,
				       okp->smk_known,
				       &tsp->smk_rules);
1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729
		if (may == -ENOENT)
			may = srp->smk_access;
		else
			may &= srp->smk_access;
		/*
		 * If may is zero the SMACK64MMAP subject can't
		 * possibly have less access.
		 */
		if (may == 0)
			continue;

		/*
		 * Fetch the global list entry.
		 * If there isn't one a SMACK64MMAP subject
		 * can't have as much access as current.
		 */
1730 1731
		mmay = smk_access_entry(mkp->smk_known, okp->smk_known,
					&mkp->smk_rules);
1732 1733 1734 1735 1736 1737 1738 1739
		if (mmay == -ENOENT) {
			rc = -EACCES;
			break;
		}
		/*
		 * If there is a local entry it modifies the
		 * potential access, too.
		 */
1740 1741
		tmay = smk_access_entry(mkp->smk_known, okp->smk_known,
					&tsp->smk_rules);
1742 1743
		if (tmay != -ENOENT)
			mmay &= tmay;
1744

1745 1746 1747 1748 1749
		/*
		 * If there is any access available to current that is
		 * not available to a SMACK64MMAP subject
		 * deny access.
		 */
1750
		if ((may | mmay) != mmay) {
1751
			rc = -EACCES;
1752
			break;
1753
		}
1754 1755 1756 1757 1758 1759 1760
	}

	rcu_read_unlock();

	return rc;
}

1761 1762 1763 1764 1765
/**
 * smack_file_set_fowner - set the file security blob value
 * @file: object in question
 *
 */
1766
static void smack_file_set_fowner(struct file *file)
1767
{
1768 1769 1770
	struct smack_known **blob = smack_file(file);

	*blob = smk_of_current();
1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786
}

/**
 * smack_file_send_sigiotask - Smack on sigio
 * @tsk: The target task
 * @fown: the object the signal come from
 * @signum: unused
 *
 * Allow a privileged task to get signals even if it shouldn't
 *
 * Returns 0 if a subject with the object's smack could
 * write to the task, an error code otherwise.
 */
static int smack_file_send_sigiotask(struct task_struct *tsk,
				     struct fown_struct *fown, int signum)
{
1787
	struct smack_known **blob;
1788
	struct smack_known *skp;
1789
	struct smack_known *tkp = smk_of_task(smack_cred(tsk->cred));
1790
	const struct cred *tcred;
1791 1792
	struct file *file;
	int rc;
E
Etienne Basset 已提交
1793
	struct smk_audit_info ad;
1794 1795 1796 1797 1798

	/*
	 * struct fown_struct is never outside the context of a struct file
	 */
	file = container_of(fown, struct file, f_owner);
1799

E
Etienne Basset 已提交
1800
	/* we don't log here as rc can be overriden */
1801 1802
	blob = smack_file(file);
	skp = *blob;
1803 1804
	rc = smk_access(skp, tkp, MAY_DELIVER, NULL);
	rc = smk_bu_note("sigiotask", skp, tkp, MAY_DELIVER, rc);
1805 1806 1807 1808

	rcu_read_lock();
	tcred = __task_cred(tsk);
	if (rc != 0 && smack_privileged_cred(CAP_MAC_OVERRIDE, tcred))
E
Etienne Basset 已提交
1809
		rc = 0;
1810
	rcu_read_unlock();
E
Etienne Basset 已提交
1811 1812 1813

	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
	smk_ad_setfield_u_tsk(&ad, tsk);
1814
	smack_log(skp->smk_known, tkp->smk_known, MAY_DELIVER, rc, &ad);
1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825
	return rc;
}

/**
 * smack_file_receive - Smack file receive check
 * @file: the object
 *
 * Returns 0 if current has access, error code otherwise
 */
static int smack_file_receive(struct file *file)
{
C
Casey Schaufler 已提交
1826
	int rc;
1827
	int may = 0;
E
Etienne Basset 已提交
1828
	struct smk_audit_info ad;
C
Casey Schaufler 已提交
1829
	struct inode *inode = file_inode(file);
C
Casey Schaufler 已提交
1830 1831 1832
	struct socket *sock;
	struct task_smack *tsp;
	struct socket_smack *ssp;
1833

1834 1835 1836
	if (unlikely(IS_PRIVATE(inode)))
		return 0;

1837
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
E
Etienne Basset 已提交
1838
	smk_ad_setfield_u_fs_path(&ad, file->f_path);
C
Casey Schaufler 已提交
1839

1840
	if (inode->i_sb->s_magic == SOCKFS_MAGIC) {
C
Casey Schaufler 已提交
1841 1842
		sock = SOCKET_I(inode);
		ssp = sock->sk->sk_security;
1843
		tsp = smack_cred(current_cred());
C
Casey Schaufler 已提交
1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857
		/*
		 * If the receiving process can't write to the
		 * passed socket or if the passed socket can't
		 * write to the receiving process don't accept
		 * the passed socket.
		 */
		rc = smk_access(tsp->smk_task, ssp->smk_out, MAY_WRITE, &ad);
		rc = smk_bu_file(file, may, rc);
		if (rc < 0)
			return rc;
		rc = smk_access(ssp->smk_in, tsp->smk_task, MAY_WRITE, &ad);
		rc = smk_bu_file(file, may, rc);
		return rc;
	}
1858 1859 1860 1861 1862 1863 1864 1865
	/*
	 * This code relies on bitmasks.
	 */
	if (file->f_mode & FMODE_READ)
		may = MAY_READ;
	if (file->f_mode & FMODE_WRITE)
		may |= MAY_WRITE;

C
Casey Schaufler 已提交
1866
	rc = smk_curacc(smk_of_inode(inode), may, &ad);
C
Casey Schaufler 已提交
1867 1868
	rc = smk_bu_file(file, may, rc);
	return rc;
1869 1870
}

1871
/**
1872
 * smack_file_open - Smack dentry open processing
1873
 * @file: the object
1874
 * @cred: task credential
1875 1876
 *
 * Set the security blob in the file structure.
1877 1878 1879
 * Allow the open only if the task has read access. There are
 * many read operations (e.g. fstat) that you can do with an
 * fd even if you have the file open write-only.
1880 1881 1882
 *
 * Returns 0
 */
A
Al Viro 已提交
1883
static int smack_file_open(struct file *file)
1884
{
1885
	struct task_smack *tsp = smack_cred(file->f_cred);
C
Casey Schaufler 已提交
1886
	struct inode *inode = file_inode(file);
1887 1888
	struct smk_audit_info ad;
	int rc;
1889

1890 1891
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
	smk_ad_setfield_u_fs_path(&ad, file->f_path);
1892
	rc = smk_tskacc(tsp, smk_of_inode(inode), MAY_READ, &ad);
A
Al Viro 已提交
1893
	rc = smk_bu_credfile(file->f_cred, file, MAY_READ, rc);
1894 1895

	return rc;
1896 1897
}

1898 1899 1900 1901
/*
 * Task hooks
 */

1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912
/**
 * smack_cred_alloc_blank - "allocate" blank task-level security credentials
 * @new: the new credentials
 * @gfp: the atomicity of any memory allocations
 *
 * Prepare a blank set of credentials for modification.  This must allocate all
 * the memory the LSM module might require such that cred_transfer() can
 * complete without error.
 */
static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp)
{
1913
	init_task_smack(smack_cred(cred), NULL, NULL);
1914 1915 1916 1917
	return 0;
}


1918
/**
1919 1920
 * smack_cred_free - "free" task-level security credentials
 * @cred: the credentials in question
1921 1922
 *
 */
1923
static void smack_cred_free(struct cred *cred)
1924
{
1925
	struct task_smack *tsp = smack_cred(cred);
1926 1927 1928 1929
	struct smack_rule *rp;
	struct list_head *l;
	struct list_head *n;

1930 1931
	smk_destroy_label_list(&tsp->smk_relabel);

1932 1933 1934
	list_for_each_safe(l, n, &tsp->smk_rules) {
		rp = list_entry(l, struct smack_rule, list);
		list_del(&rp->list);
1935
		kmem_cache_free(smack_rule_cache, rp);
1936
	}
1937 1938
}

D
David Howells 已提交
1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949
/**
 * smack_cred_prepare - prepare new set of credentials for modification
 * @new: the new credentials
 * @old: the original credentials
 * @gfp: the atomicity of any memory allocations
 *
 * Prepare a new set of credentials for modification.
 */
static int smack_cred_prepare(struct cred *new, const struct cred *old,
			      gfp_t gfp)
{
1950
	struct task_smack *old_tsp = smack_cred(old);
1951
	struct task_smack *new_tsp = smack_cred(new);
1952
	int rc;
1953

1954
	init_task_smack(new_tsp, old_tsp->smk_task, old_tsp->smk_task);
1955

1956 1957 1958 1959
	rc = smk_copy_rules(&new_tsp->smk_rules, &old_tsp->smk_rules, gfp);
	if (rc != 0)
		return rc;

1960 1961
	rc = smk_copy_relabel(&new_tsp->smk_relabel, &old_tsp->smk_relabel,
				gfp);
1962
	return rc;
D
David Howells 已提交
1963 1964
}

1965 1966 1967 1968 1969 1970 1971 1972 1973
/**
 * smack_cred_transfer - Transfer the old credentials to the new credentials
 * @new: the new credentials
 * @old: the original credentials
 *
 * Fill in a set of blank credentials from another set of credentials.
 */
static void smack_cred_transfer(struct cred *new, const struct cred *old)
{
1974 1975
	struct task_smack *old_tsp = smack_cred(old);
	struct task_smack *new_tsp = smack_cred(new);
1976 1977 1978

	new_tsp->smk_task = old_tsp->smk_task;
	new_tsp->smk_forked = old_tsp->smk_task;
1979 1980 1981 1982
	mutex_init(&new_tsp->smk_rules_lock);
	INIT_LIST_HEAD(&new_tsp->smk_rules);

	/* cbs copy rule list */
1983 1984
}

1985 1986 1987 1988 1989 1990 1991
/**
 * smack_cred_getsecid - get the secid corresponding to a creds structure
 * @c: the object creds
 * @secid: where to put the result
 *
 * Sets the secid to contain a u32 version of the smack label.
 */
1992
static void smack_cred_getsecid(const struct cred *cred, u32 *secid)
1993 1994 1995 1996
{
	struct smack_known *skp;

	rcu_read_lock();
1997
	skp = smk_of_task(smack_cred(cred));
1998 1999 2000 2001
	*secid = skp->smk_secid;
	rcu_read_unlock();
}

2002 2003
/**
 * smack_kernel_act_as - Set the subjective context in a set of credentials
2004 2005
 * @new: points to the set of credentials to be modified.
 * @secid: specifies the security ID to be set
2006 2007 2008 2009 2010
 *
 * Set the security data for a kernel service.
 */
static int smack_kernel_act_as(struct cred *new, u32 secid)
{
2011
	struct task_smack *new_tsp = smack_cred(new);
2012

2013
	new_tsp->smk_task = smack_from_secid(secid);
2014 2015 2016 2017 2018
	return 0;
}

/**
 * smack_kernel_create_files_as - Set the file creation label in a set of creds
2019 2020
 * @new: points to the set of credentials to be modified
 * @inode: points to the inode to use as a reference
2021 2022 2023 2024 2025 2026 2027
 *
 * Set the file creation context in a set of credentials to the same
 * as the objective context of the specified inode
 */
static int smack_kernel_create_files_as(struct cred *new,
					struct inode *inode)
{
2028
	struct inode_smack *isp = smack_inode(inode);
2029
	struct task_smack *tsp = smack_cred(new);
2030

2031
	tsp->smk_forked = isp->smk_inode;
2032
	tsp->smk_task = tsp->smk_forked;
2033 2034 2035
	return 0;
}

E
Etienne Basset 已提交
2036 2037 2038
/**
 * smk_curacc_on_task - helper to log task related access
 * @p: the task object
2039 2040
 * @access: the access requested
 * @caller: name of the calling function for audit
E
Etienne Basset 已提交
2041 2042 2043
 *
 * Return 0 if access is permitted
 */
2044 2045
static int smk_curacc_on_task(struct task_struct *p, int access,
				const char *caller)
E
Etienne Basset 已提交
2046 2047
{
	struct smk_audit_info ad;
2048
	struct smack_known *skp = smk_of_task_struct(p);
C
Casey Schaufler 已提交
2049
	int rc;
E
Etienne Basset 已提交
2050

2051
	smk_ad_init(&ad, caller, LSM_AUDIT_DATA_TASK);
E
Etienne Basset 已提交
2052
	smk_ad_setfield_u_tsk(&ad, p);
2053
	rc = smk_curacc(skp, access, &ad);
C
Casey Schaufler 已提交
2054 2055
	rc = smk_bu_task(p, access, rc);
	return rc;
E
Etienne Basset 已提交
2056 2057
}

2058 2059 2060 2061 2062 2063 2064 2065 2066
/**
 * smack_task_setpgid - Smack check on setting pgid
 * @p: the task object
 * @pgid: unused
 *
 * Return 0 if write access is permitted
 */
static int smack_task_setpgid(struct task_struct *p, pid_t pgid)
{
2067
	return smk_curacc_on_task(p, MAY_WRITE, __func__);
2068 2069 2070 2071 2072 2073 2074 2075 2076 2077
}

/**
 * smack_task_getpgid - Smack access check for getpgid
 * @p: the object task
 *
 * Returns 0 if current can read the object task, error code otherwise
 */
static int smack_task_getpgid(struct task_struct *p)
{
2078
	return smk_curacc_on_task(p, MAY_READ, __func__);
2079 2080 2081 2082 2083 2084 2085 2086 2087 2088
}

/**
 * smack_task_getsid - Smack access check for getsid
 * @p: the object task
 *
 * Returns 0 if current can read the object task, error code otherwise
 */
static int smack_task_getsid(struct task_struct *p)
{
2089
	return smk_curacc_on_task(p, MAY_READ, __func__);
2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100
}

/**
 * smack_task_getsecid - get the secid of the task
 * @p: the object task
 * @secid: where to put the result
 *
 * Sets the secid to contain a u32 version of the smack label.
 */
static void smack_task_getsecid(struct task_struct *p, u32 *secid)
{
2101
	struct smack_known *skp = smk_of_task_struct(p);
2102 2103

	*secid = skp->smk_secid;
2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114
}

/**
 * smack_task_setnice - Smack check on setting nice
 * @p: the task object
 * @nice: unused
 *
 * Return 0 if write access is permitted
 */
static int smack_task_setnice(struct task_struct *p, int nice)
{
C
Casey Schaufler 已提交
2115
	return smk_curacc_on_task(p, MAY_WRITE, __func__);
2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126
}

/**
 * smack_task_setioprio - Smack check on setting ioprio
 * @p: the task object
 * @ioprio: unused
 *
 * Return 0 if write access is permitted
 */
static int smack_task_setioprio(struct task_struct *p, int ioprio)
{
C
Casey Schaufler 已提交
2127
	return smk_curacc_on_task(p, MAY_WRITE, __func__);
2128 2129 2130 2131 2132 2133 2134 2135 2136 2137
}

/**
 * smack_task_getioprio - Smack check on reading ioprio
 * @p: the task object
 *
 * Return 0 if read access is permitted
 */
static int smack_task_getioprio(struct task_struct *p)
{
2138
	return smk_curacc_on_task(p, MAY_READ, __func__);
2139 2140 2141 2142 2143 2144 2145 2146 2147 2148
}

/**
 * smack_task_setscheduler - Smack check on setting scheduler
 * @p: the task object
 * @policy: unused
 * @lp: unused
 *
 * Return 0 if read access is permitted
 */
2149
static int smack_task_setscheduler(struct task_struct *p)
2150
{
C
Casey Schaufler 已提交
2151
	return smk_curacc_on_task(p, MAY_WRITE, __func__);
2152 2153 2154 2155 2156 2157 2158 2159 2160 2161
}

/**
 * smack_task_getscheduler - Smack check on reading scheduler
 * @p: the task object
 *
 * Return 0 if read access is permitted
 */
static int smack_task_getscheduler(struct task_struct *p)
{
2162
	return smk_curacc_on_task(p, MAY_READ, __func__);
2163 2164 2165 2166 2167 2168 2169 2170 2171 2172
}

/**
 * smack_task_movememory - Smack check on moving memory
 * @p: the task object
 *
 * Return 0 if write access is permitted
 */
static int smack_task_movememory(struct task_struct *p)
{
2173
	return smk_curacc_on_task(p, MAY_WRITE, __func__);
2174 2175 2176 2177 2178 2179 2180
}

/**
 * smack_task_kill - Smack check on signal delivery
 * @p: the task object
 * @info: unused
 * @sig: unused
2181
 * @cred: identifies the cred to use in lieu of current's
2182 2183 2184 2185
 *
 * Return 0 if write access is permitted
 *
 */
2186
static int smack_task_kill(struct task_struct *p, struct kernel_siginfo *info,
2187
			   int sig, const struct cred *cred)
2188
{
E
Etienne Basset 已提交
2189
	struct smk_audit_info ad;
2190
	struct smack_known *skp;
2191
	struct smack_known *tkp = smk_of_task_struct(p);
C
Casey Schaufler 已提交
2192
	int rc;
E
Etienne Basset 已提交
2193

2194 2195 2196
	if (!sig)
		return 0; /* null signal; existence test */

E
Etienne Basset 已提交
2197 2198
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
	smk_ad_setfield_u_tsk(&ad, p);
2199 2200 2201 2202
	/*
	 * Sending a signal requires that the sender
	 * can write the receiver.
	 */
2203
	if (cred == NULL) {
2204 2205
		rc = smk_curacc(tkp, MAY_DELIVER, &ad);
		rc = smk_bu_task(p, MAY_DELIVER, rc);
C
Casey Schaufler 已提交
2206 2207
		return rc;
	}
2208
	/*
2209
	 * If the cred isn't NULL we're dealing with some USB IO
2210 2211 2212
	 * specific behavior. This is not clean. For one thing
	 * we can't take privilege into account.
	 */
2213
	skp = smk_of_task(smack_cred(cred));
2214 2215
	rc = smk_access(skp, tkp, MAY_DELIVER, &ad);
	rc = smk_bu_note("USB signal", skp, tkp, MAY_DELIVER, rc);
C
Casey Schaufler 已提交
2216
	return rc;
2217 2218 2219 2220 2221
}

/**
 * smack_task_to_inode - copy task smack into the inode blob
 * @p: task to copy from
2222
 * @inode: inode to copy to
2223 2224 2225 2226 2227
 *
 * Sets the smack pointer in the inode security blob
 */
static void smack_task_to_inode(struct task_struct *p, struct inode *inode)
{
2228
	struct inode_smack *isp = smack_inode(inode);
2229
	struct smack_known *skp = smk_of_task_struct(p);
2230

2231
	isp->smk_inode = skp;
2232
	isp->smk_flags |= SMK_INODE_INSTANT;
2233 2234 2235 2236 2237 2238 2239 2240 2241 2242
}

/*
 * Socket hooks.
 */

/**
 * smack_sk_alloc_security - Allocate a socket blob
 * @sk: the socket
 * @family: unused
2243
 * @gfp_flags: memory allocation flags
2244 2245 2246 2247 2248 2249 2250
 *
 * Assign Smack pointers to current
 *
 * Returns 0 on success, -ENOMEM is there's no memory
 */
static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
{
2251
	struct smack_known *skp = smk_of_current();
2252 2253 2254 2255 2256 2257
	struct socket_smack *ssp;

	ssp = kzalloc(sizeof(struct socket_smack), gfp_flags);
	if (ssp == NULL)
		return -ENOMEM;

2258 2259 2260 2261 2262 2263 2264 2265 2266 2267
	/*
	 * Sockets created by kernel threads receive web label.
	 */
	if (unlikely(current->flags & PF_KTHREAD)) {
		ssp->smk_in = &smack_known_web;
		ssp->smk_out = &smack_known_web;
	} else {
		ssp->smk_in = skp;
		ssp->smk_out = skp;
	}
2268
	ssp->smk_packet = NULL;
2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282

	sk->sk_security = ssp;

	return 0;
}

/**
 * smack_sk_free_security - Free a socket blob
 * @sk: the socket
 *
 * Clears the blob pointer
 */
static void smack_sk_free_security(struct sock *sk)
{
2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296
#ifdef SMACK_IPV6_PORT_LABELING
	struct smk_port_label *spp;

	if (sk->sk_family == PF_INET6) {
		rcu_read_lock();
		list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) {
			if (spp->smk_sock != sk)
				continue;
			spp->smk_can_reuse = 1;
			break;
		}
		rcu_read_unlock();
	}
#endif
2297 2298 2299
	kfree(sk->sk_security);
}

2300
/**
C
Casey Schaufler 已提交
2301
* smack_ipv4host_label - check host based restrictions
2302 2303 2304 2305 2306 2307 2308 2309 2310 2311
* @sip: the object end
*
* looks for host based access restrictions
*
* This version will only be appropriate for really small sets of single label
* hosts.  The caller is responsible for ensuring that the RCU read lock is
* taken before calling this function.
*
* Returns the label of the far end or NULL if it's not special.
*/
C
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2312
static struct smack_known *smack_ipv4host_label(struct sockaddr_in *sip)
2313
{
C
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2314
	struct smk_net4addr *snp;
2315 2316 2317 2318 2319
	struct in_addr *siap = &sip->sin_addr;

	if (siap->s_addr == 0)
		return NULL;

C
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2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376
	list_for_each_entry_rcu(snp, &smk_net4addr_list, list)
		/*
		 * we break after finding the first match because
		 * the list is sorted from longest to shortest mask
		 * so we have found the most specific match
		 */
		if (snp->smk_host.s_addr ==
		    (siap->s_addr & snp->smk_mask.s_addr))
			return snp->smk_label;

	return NULL;
}

#if IS_ENABLED(CONFIG_IPV6)
/*
 * smk_ipv6_localhost - Check for local ipv6 host address
 * @sip: the address
 *
 * Returns boolean true if this is the localhost address
 */
static bool smk_ipv6_localhost(struct sockaddr_in6 *sip)
{
	__be16 *be16p = (__be16 *)&sip->sin6_addr;
	__be32 *be32p = (__be32 *)&sip->sin6_addr;

	if (be32p[0] == 0 && be32p[1] == 0 && be32p[2] == 0 && be16p[6] == 0 &&
	    ntohs(be16p[7]) == 1)
		return true;
	return false;
}

/**
* smack_ipv6host_label - check host based restrictions
* @sip: the object end
*
* looks for host based access restrictions
*
* This version will only be appropriate for really small sets of single label
* hosts.  The caller is responsible for ensuring that the RCU read lock is
* taken before calling this function.
*
* Returns the label of the far end or NULL if it's not special.
*/
static struct smack_known *smack_ipv6host_label(struct sockaddr_in6 *sip)
{
	struct smk_net6addr *snp;
	struct in6_addr *sap = &sip->sin6_addr;
	int i;
	int found = 0;

	/*
	 * It's local. Don't look for a host label.
	 */
	if (smk_ipv6_localhost(sip))
		return NULL;

	list_for_each_entry_rcu(snp, &smk_net6addr_list, list) {
C
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2377 2378 2379 2380 2381 2382
		/*
		 * If the label is NULL the entry has
		 * been renounced. Ignore it.
		 */
		if (snp->smk_label == NULL)
			continue;
2383 2384 2385 2386 2387
		/*
		* we break after finding the first match because
		* the list is sorted from longest to shortest mask
		* so we have found the most specific match
		*/
C
Casey Schaufler 已提交
2388 2389 2390 2391 2392 2393
		for (found = 1, i = 0; i < 8; i++) {
			if ((sap->s6_addr16[i] & snp->smk_mask.s6_addr16[i]) !=
			    snp->smk_host.s6_addr16[i]) {
				found = 0;
				break;
			}
2394
		}
C
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2395 2396 2397
		if (found)
			return snp->smk_label;
	}
2398 2399 2400

	return NULL;
}
C
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2401
#endif /* CONFIG_IPV6 */
2402

2403 2404 2405
/**
 * smack_netlabel - Set the secattr on a socket
 * @sk: the socket
2406
 * @labeled: socket label scheme
2407 2408 2409 2410 2411 2412
 *
 * Convert the outbound smack value (smk_out) to a
 * secattr and attach it to the socket.
 *
 * Returns 0 on success or an error code
 */
2413
static int smack_netlabel(struct sock *sk, int labeled)
2414
{
2415
	struct smack_known *skp;
2416
	struct socket_smack *ssp = sk->sk_security;
2417
	int rc = 0;
2418

2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433
	/*
	 * Usually the netlabel code will handle changing the
	 * packet labeling based on the label.
	 * The case of a single label host is different, because
	 * a single label host should never get a labeled packet
	 * even though the label is usually associated with a packet
	 * label.
	 */
	local_bh_disable();
	bh_lock_sock_nested(sk);

	if (ssp->smk_out == smack_net_ambient ||
	    labeled == SMACK_UNLABELED_SOCKET)
		netlbl_sock_delattr(sk);
	else {
2434
		skp = ssp->smk_out;
2435
		rc = netlbl_sock_setattr(sk, sk->sk_family, &skp->smk_netlabel);
2436 2437 2438 2439
	}

	bh_unlock_sock(sk);
	local_bh_enable();
2440

2441 2442 2443
	return rc;
}

2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456
/**
 * smack_netlbel_send - Set the secattr on a socket and perform access checks
 * @sk: the socket
 * @sap: the destination address
 *
 * Set the correct secattr for the given socket based on the destination
 * address and perform any outbound access checks needed.
 *
 * Returns 0 on success or an error code.
 *
 */
static int smack_netlabel_send(struct sock *sk, struct sockaddr_in *sap)
{
2457
	struct smack_known *skp;
2458 2459
	int rc;
	int sk_lbl;
2460
	struct smack_known *hkp;
2461
	struct socket_smack *ssp = sk->sk_security;
E
Etienne Basset 已提交
2462
	struct smk_audit_info ad;
2463 2464

	rcu_read_lock();
C
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2465
	hkp = smack_ipv4host_label(sap);
2466
	if (hkp != NULL) {
E
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2467
#ifdef CONFIG_AUDIT
2468 2469
		struct lsm_network_audit net;

2470 2471 2472 2473
		smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
		ad.a.u.net->family = sap->sin_family;
		ad.a.u.net->dport = sap->sin_port;
		ad.a.u.net->v4info.daddr = sap->sin_addr.s_addr;
E
Etienne Basset 已提交
2474
#endif
2475
		sk_lbl = SMACK_UNLABELED_SOCKET;
2476
		skp = ssp->smk_out;
2477 2478
		rc = smk_access(skp, hkp, MAY_WRITE, &ad);
		rc = smk_bu_note("IPv4 host check", skp, hkp, MAY_WRITE, rc);
2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489
	} else {
		sk_lbl = SMACK_CIPSO_SOCKET;
		rc = 0;
	}
	rcu_read_unlock();
	if (rc != 0)
		return rc;

	return smack_netlabel(sk, sk_lbl);
}

C
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2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525
#if IS_ENABLED(CONFIG_IPV6)
/**
 * smk_ipv6_check - check Smack access
 * @subject: subject Smack label
 * @object: object Smack label
 * @address: address
 * @act: the action being taken
 *
 * Check an IPv6 access
 */
static int smk_ipv6_check(struct smack_known *subject,
				struct smack_known *object,
				struct sockaddr_in6 *address, int act)
{
#ifdef CONFIG_AUDIT
	struct lsm_network_audit net;
#endif
	struct smk_audit_info ad;
	int rc;

#ifdef CONFIG_AUDIT
	smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
	ad.a.u.net->family = PF_INET6;
	ad.a.u.net->dport = ntohs(address->sin6_port);
	if (act == SMK_RECEIVING)
		ad.a.u.net->v6info.saddr = address->sin6_addr;
	else
		ad.a.u.net->v6info.daddr = address->sin6_addr;
#endif
	rc = smk_access(subject, object, MAY_WRITE, &ad);
	rc = smk_bu_note("IPv6 check", subject, object, MAY_WRITE, rc);
	return rc;
}
#endif /* CONFIG_IPV6 */

#ifdef SMACK_IPV6_PORT_LABELING
2526 2527 2528 2529 2530 2531 2532 2533 2534 2535 2536 2537 2538 2539 2540 2541 2542 2543 2544 2545 2546
/**
 * smk_ipv6_port_label - Smack port access table management
 * @sock: socket
 * @address: address
 *
 * Create or update the port list entry
 */
static void smk_ipv6_port_label(struct socket *sock, struct sockaddr *address)
{
	struct sock *sk = sock->sk;
	struct sockaddr_in6 *addr6;
	struct socket_smack *ssp = sock->sk->sk_security;
	struct smk_port_label *spp;
	unsigned short port = 0;

	if (address == NULL) {
		/*
		 * This operation is changing the Smack information
		 * on the bound socket. Take the changes to the port
		 * as well.
		 */
2547 2548
		rcu_read_lock();
		list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) {
2549 2550 2551 2552
			if (sk != spp->smk_sock)
				continue;
			spp->smk_in = ssp->smk_in;
			spp->smk_out = ssp->smk_out;
2553
			rcu_read_unlock();
2554 2555 2556 2557 2558 2559
			return;
		}
		/*
		 * A NULL address is only used for updating existing
		 * bound entries. If there isn't one, it's OK.
		 */
2560
		rcu_read_unlock();
2561 2562 2563 2564 2565 2566 2567 2568 2569 2570 2571 2572 2573 2574 2575
		return;
	}

	addr6 = (struct sockaddr_in6 *)address;
	port = ntohs(addr6->sin6_port);
	/*
	 * This is a special case that is safely ignored.
	 */
	if (port == 0)
		return;

	/*
	 * Look for an existing port list entry.
	 * This is an indication that a port is getting reused.
	 */
2576 2577
	rcu_read_lock();
	list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) {
2578
		if (spp->smk_port != port || spp->smk_sock_type != sock->type)
2579
			continue;
2580 2581 2582 2583
		if (spp->smk_can_reuse != 1) {
			rcu_read_unlock();
			return;
		}
2584 2585 2586 2587
		spp->smk_port = port;
		spp->smk_sock = sk;
		spp->smk_in = ssp->smk_in;
		spp->smk_out = ssp->smk_out;
2588
		spp->smk_can_reuse = 0;
2589
		rcu_read_unlock();
2590 2591
		return;
	}
2592
	rcu_read_unlock();
2593 2594 2595 2596 2597 2598 2599 2600 2601 2602 2603
	/*
	 * A new port entry is required.
	 */
	spp = kzalloc(sizeof(*spp), GFP_KERNEL);
	if (spp == NULL)
		return;

	spp->smk_port = port;
	spp->smk_sock = sk;
	spp->smk_in = ssp->smk_in;
	spp->smk_out = ssp->smk_out;
2604
	spp->smk_sock_type = sock->type;
2605
	spp->smk_can_reuse = 0;
2606

2607 2608 2609
	mutex_lock(&smack_ipv6_lock);
	list_add_rcu(&spp->list, &smk_ipv6_port_list);
	mutex_unlock(&smack_ipv6_lock);
2610 2611 2612 2613 2614 2615 2616 2617 2618 2619
	return;
}

/**
 * smk_ipv6_port_check - check Smack port access
 * @sock: socket
 * @address: address
 *
 * Create or update the port list entry
 */
2620
static int smk_ipv6_port_check(struct sock *sk, struct sockaddr_in6 *address,
2621 2622 2623 2624
				int act)
{
	struct smk_port_label *spp;
	struct socket_smack *ssp = sk->sk_security;
C
Casey Schaufler 已提交
2625 2626
	struct smack_known *skp = NULL;
	unsigned short port;
2627
	struct smack_known *object;
2628 2629

	if (act == SMK_RECEIVING) {
C
Casey Schaufler 已提交
2630
		skp = smack_ipv6host_label(address);
2631
		object = ssp->smk_in;
2632
	} else {
2633
		skp = ssp->smk_out;
C
Casey Schaufler 已提交
2634
		object = smack_ipv6host_label(address);
2635 2636 2637
	}

	/*
C
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2638
	 * The other end is a single label host.
2639
	 */
C
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2640 2641 2642 2643 2644 2645
	if (skp != NULL && object != NULL)
		return smk_ipv6_check(skp, object, address, act);
	if (skp == NULL)
		skp = smack_net_ambient;
	if (object == NULL)
		object = smack_net_ambient;
2646 2647 2648 2649

	/*
	 * It's remote, so port lookup does no good.
	 */
C
Casey Schaufler 已提交
2650 2651
	if (!smk_ipv6_localhost(address))
		return smk_ipv6_check(skp, object, address, act);
2652 2653 2654 2655

	/*
	 * It's local so the send check has to have passed.
	 */
C
Casey Schaufler 已提交
2656 2657
	if (act == SMK_RECEIVING)
		return 0;
2658

C
Casey Schaufler 已提交
2659
	port = ntohs(address->sin6_port);
2660 2661
	rcu_read_lock();
	list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) {
2662
		if (spp->smk_port != port || spp->smk_sock_type != sk->sk_type)
2663
			continue;
2664
		object = spp->smk_in;
2665
		if (act == SMK_CONNECTING)
2666
			ssp->smk_packet = spp->smk_out;
2667 2668
		break;
	}
2669
	rcu_read_unlock();
2670

C
Casey Schaufler 已提交
2671
	return smk_ipv6_check(skp, object, address, act);
2672
}
C
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2673
#endif /* SMACK_IPV6_PORT_LABELING */
2674

2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686 2687 2688 2689
/**
 * smack_inode_setsecurity - set smack xattrs
 * @inode: the object
 * @name: attribute name
 * @value: attribute value
 * @size: size of the attribute
 * @flags: unused
 *
 * Sets the named attribute in the appropriate blob
 *
 * Returns 0 on success, or an error code
 */
static int smack_inode_setsecurity(struct inode *inode, const char *name,
				   const void *value, size_t size, int flags)
{
2690
	struct smack_known *skp;
2691
	struct inode_smack *nsp = smack_inode(inode);
2692 2693
	struct socket_smack *ssp;
	struct socket *sock;
2694
	int rc = 0;
2695

2696
	if (value == NULL || size > SMK_LONGLABEL || size == 0)
P
Pankaj Kumar 已提交
2697
		return -EINVAL;
2698

2699
	skp = smk_import_entry(value, size);
2700 2701
	if (IS_ERR(skp))
		return PTR_ERR(skp);
2702 2703

	if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
2704
		nsp->smk_inode = skp;
2705
		nsp->smk_flags |= SMK_INODE_INSTANT;
2706 2707 2708 2709 2710 2711 2712 2713 2714
		return 0;
	}
	/*
	 * The rest of the Smack xattrs are only on sockets.
	 */
	if (inode->i_sb->s_magic != SOCKFS_MAGIC)
		return -EOPNOTSUPP;

	sock = SOCKET_I(inode);
2715
	if (sock == NULL || sock->sk == NULL)
2716 2717 2718 2719 2720
		return -EOPNOTSUPP;

	ssp = sock->sk->sk_security;

	if (strcmp(name, XATTR_SMACK_IPIN) == 0)
2721
		ssp->smk_in = skp;
2722
	else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) {
2723
		ssp->smk_out = skp;
2724
		if (sock->sk->sk_family == PF_INET) {
C
Casey Schaufler 已提交
2725 2726 2727 2728 2729 2730
			rc = smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
			if (rc != 0)
				printk(KERN_WARNING
					"Smack: \"%s\" netlbl error %d.\n",
					__func__, -rc);
		}
2731 2732 2733
	} else
		return -EOPNOTSUPP;

C
Casey Schaufler 已提交
2734
#ifdef SMACK_IPV6_PORT_LABELING
2735 2736
	if (sock->sk->sk_family == PF_INET6)
		smk_ipv6_port_label(sock, NULL);
C
Casey Schaufler 已提交
2737
#endif
2738

2739 2740 2741 2742 2743 2744 2745 2746 2747 2748 2749 2750 2751 2752 2753 2754 2755 2756
	return 0;
}

/**
 * smack_socket_post_create - finish socket setup
 * @sock: the socket
 * @family: protocol family
 * @type: unused
 * @protocol: unused
 * @kern: unused
 *
 * Sets the netlabel information on the socket
 *
 * Returns 0 on success, and error code otherwise
 */
static int smack_socket_post_create(struct socket *sock, int family,
				    int type, int protocol, int kern)
{
2757 2758 2759 2760 2761 2762 2763 2764 2765 2766 2767 2768 2769 2770 2771
	struct socket_smack *ssp;

	if (sock->sk == NULL)
		return 0;

	/*
	 * Sockets created by kernel threads receive web label.
	 */
	if (unlikely(current->flags & PF_KTHREAD)) {
		ssp = sock->sk->sk_security;
		ssp->smk_in = &smack_known_web;
		ssp->smk_out = &smack_known_web;
	}

	if (family != PF_INET)
2772 2773 2774 2775
		return 0;
	/*
	 * Set the outbound netlbl.
	 */
2776 2777 2778
	return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
}

2779 2780 2781 2782 2783 2784 2785 2786 2787 2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 2799
/**
 * smack_socket_socketpair - create socket pair
 * @socka: one socket
 * @sockb: another socket
 *
 * Cross reference the peer labels for SO_PEERSEC
 *
 * Returns 0 on success, and error code otherwise
 */
static int smack_socket_socketpair(struct socket *socka,
		                   struct socket *sockb)
{
	struct socket_smack *asp = socka->sk->sk_security;
	struct socket_smack *bsp = sockb->sk->sk_security;

	asp->smk_packet = bsp->smk_out;
	bsp->smk_packet = asp->smk_out;

	return 0;
}

C
Casey Schaufler 已提交
2800
#ifdef SMACK_IPV6_PORT_LABELING
2801 2802 2803 2804 2805 2806 2807 2808
/**
 * smack_socket_bind - record port binding information.
 * @sock: the socket
 * @address: the port address
 * @addrlen: size of the address
 *
 * Records the label bound to a port.
 *
2809
 * Returns 0 on success, and error code otherwise
2810 2811 2812 2813
 */
static int smack_socket_bind(struct socket *sock, struct sockaddr *address,
				int addrlen)
{
2814 2815 2816 2817
	if (sock->sk != NULL && sock->sk->sk_family == PF_INET6) {
		if (addrlen < SIN6_LEN_RFC2133 ||
		    address->sa_family != AF_INET6)
			return -EINVAL;
2818
		smk_ipv6_port_label(sock, address);
2819
	}
2820 2821
	return 0;
}
C
Casey Schaufler 已提交
2822
#endif /* SMACK_IPV6_PORT_LABELING */
2823

2824 2825 2826 2827 2828 2829 2830 2831 2832 2833 2834 2835 2836
/**
 * smack_socket_connect - connect access check
 * @sock: the socket
 * @sap: the other end
 * @addrlen: size of sap
 *
 * Verifies that a connection may be possible
 *
 * Returns 0 on success, and error code otherwise
 */
static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
				int addrlen)
{
2837
	int rc = 0;
C
Casey Schaufler 已提交
2838 2839 2840 2841 2842
#if IS_ENABLED(CONFIG_IPV6)
	struct sockaddr_in6 *sip = (struct sockaddr_in6 *)sap;
#endif
#ifdef SMACK_IPV6_SECMARK_LABELING
	struct smack_known *rsp;
2843
	struct socket_smack *ssp;
C
Casey Schaufler 已提交
2844
#endif
2845 2846

	if (sock->sk == NULL)
2847 2848
		return 0;

2849 2850 2851 2852
#ifdef SMACK_IPV6_SECMARK_LABELING
	ssp = sock->sk->sk_security;
#endif

2853 2854
	switch (sock->sk->sk_family) {
	case PF_INET:
2855 2856
		if (addrlen < sizeof(struct sockaddr_in) ||
		    sap->sa_family != AF_INET)
2857 2858 2859 2860
			return -EINVAL;
		rc = smack_netlabel_send(sock->sk, (struct sockaddr_in *)sap);
		break;
	case PF_INET6:
2861
		if (addrlen < SIN6_LEN_RFC2133 || sap->sa_family != AF_INET6)
2862
			return -EINVAL;
C
Casey Schaufler 已提交
2863 2864 2865 2866
#ifdef SMACK_IPV6_SECMARK_LABELING
		rsp = smack_ipv6host_label(sip);
		if (rsp != NULL)
			rc = smk_ipv6_check(ssp->smk_out, rsp, sip,
2867
						SMK_CONNECTING);
C
Casey Schaufler 已提交
2868 2869 2870 2871
#endif
#ifdef SMACK_IPV6_PORT_LABELING
		rc = smk_ipv6_port_check(sock->sk, sip, SMK_CONNECTING);
#endif
2872 2873 2874
		break;
	}
	return rc;
2875 2876 2877 2878 2879 2880 2881 2882 2883 2884 2885 2886 2887 2888 2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900 2901 2902 2903 2904
}

/**
 * smack_flags_to_may - convert S_ to MAY_ values
 * @flags: the S_ value
 *
 * Returns the equivalent MAY_ value
 */
static int smack_flags_to_may(int flags)
{
	int may = 0;

	if (flags & S_IRUGO)
		may |= MAY_READ;
	if (flags & S_IWUGO)
		may |= MAY_WRITE;
	if (flags & S_IXUGO)
		may |= MAY_EXEC;

	return may;
}

/**
 * smack_msg_msg_alloc_security - Set the security blob for msg_msg
 * @msg: the object
 *
 * Returns 0
 */
static int smack_msg_msg_alloc_security(struct msg_msg *msg)
{
2905
	struct smack_known **blob = smack_msg_msg(msg);
2906

2907
	*blob = smk_of_current();
2908 2909 2910 2911
	return 0;
}

/**
2912 2913
 * smack_of_ipc - the smack pointer for the ipc
 * @isp: the object
2914 2915 2916
 *
 * Returns a pointer to the smack value
 */
2917
static struct smack_known *smack_of_ipc(struct kern_ipc_perm *isp)
2918
{
2919 2920 2921
	struct smack_known **blob = smack_ipc(isp);

	return *blob;
2922 2923 2924
}

/**
2925 2926
 * smack_ipc_alloc_security - Set the security blob for ipc
 * @isp: the object
2927 2928 2929
 *
 * Returns 0
 */
2930
static int smack_ipc_alloc_security(struct kern_ipc_perm *isp)
2931
{
2932
	struct smack_known **blob = smack_ipc(isp);
2933

2934
	*blob = smk_of_current();
2935 2936 2937
	return 0;
}

E
Etienne Basset 已提交
2938 2939
/**
 * smk_curacc_shm : check if current has access on shm
2940
 * @isp : the object
E
Etienne Basset 已提交
2941 2942 2943 2944
 * @access : access requested
 *
 * Returns 0 if current has the requested access, error code otherwise
 */
2945
static int smk_curacc_shm(struct kern_ipc_perm *isp, int access)
E
Etienne Basset 已提交
2946
{
2947
	struct smack_known *ssp = smack_of_ipc(isp);
E
Etienne Basset 已提交
2948
	struct smk_audit_info ad;
C
Casey Schaufler 已提交
2949
	int rc;
E
Etienne Basset 已提交
2950 2951 2952

#ifdef CONFIG_AUDIT
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2953
	ad.a.u.ipc_id = isp->id;
E
Etienne Basset 已提交
2954
#endif
C
Casey Schaufler 已提交
2955 2956 2957
	rc = smk_curacc(ssp, access, &ad);
	rc = smk_bu_current("shm", ssp, access, rc);
	return rc;
E
Etienne Basset 已提交
2958 2959
}

2960 2961
/**
 * smack_shm_associate - Smack access check for shm
2962
 * @isp: the object
2963 2964 2965 2966
 * @shmflg: access requested
 *
 * Returns 0 if current has the requested access, error code otherwise
 */
2967
static int smack_shm_associate(struct kern_ipc_perm *isp, int shmflg)
2968 2969 2970 2971
{
	int may;

	may = smack_flags_to_may(shmflg);
2972
	return smk_curacc_shm(isp, may);
2973 2974 2975 2976
}

/**
 * smack_shm_shmctl - Smack access check for shm
2977
 * @isp: the object
2978 2979 2980 2981
 * @cmd: what it wants to do
 *
 * Returns 0 if current has the requested access, error code otherwise
 */
2982
static int smack_shm_shmctl(struct kern_ipc_perm *isp, int cmd)
2983 2984 2985 2986 2987 2988
{
	int may;

	switch (cmd) {
	case IPC_STAT:
	case SHM_STAT:
2989
	case SHM_STAT_ANY:
2990 2991 2992 2993 2994 2995 2996 2997 2998 2999 3000 3001 3002 3003 3004 3005 3006
		may = MAY_READ;
		break;
	case IPC_SET:
	case SHM_LOCK:
	case SHM_UNLOCK:
	case IPC_RMID:
		may = MAY_READWRITE;
		break;
	case IPC_INFO:
	case SHM_INFO:
		/*
		 * System level information.
		 */
		return 0;
	default:
		return -EINVAL;
	}
3007
	return smk_curacc_shm(isp, may);
3008 3009 3010 3011
}

/**
 * smack_shm_shmat - Smack access for shmat
3012
 * @isp: the object
3013 3014 3015 3016 3017
 * @shmaddr: unused
 * @shmflg: access requested
 *
 * Returns 0 if current has the requested access, error code otherwise
 */
3018
static int smack_shm_shmat(struct kern_ipc_perm *ipc, char __user *shmaddr,
3019 3020 3021 3022 3023
			   int shmflg)
{
	int may;

	may = smack_flags_to_may(shmflg);
3024
	return smk_curacc_shm(ipc, may);
3025 3026
}

E
Etienne Basset 已提交
3027 3028
/**
 * smk_curacc_sem : check if current has access on sem
3029
 * @isp : the object
E
Etienne Basset 已提交
3030 3031 3032 3033
 * @access : access requested
 *
 * Returns 0 if current has the requested access, error code otherwise
 */
3034
static int smk_curacc_sem(struct kern_ipc_perm *isp, int access)
E
Etienne Basset 已提交
3035
{
3036
	struct smack_known *ssp = smack_of_ipc(isp);
E
Etienne Basset 已提交
3037
	struct smk_audit_info ad;
C
Casey Schaufler 已提交
3038
	int rc;
E
Etienne Basset 已提交
3039 3040 3041

#ifdef CONFIG_AUDIT
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
3042
	ad.a.u.ipc_id = isp->id;
E
Etienne Basset 已提交
3043
#endif
C
Casey Schaufler 已提交
3044 3045 3046
	rc = smk_curacc(ssp, access, &ad);
	rc = smk_bu_current("sem", ssp, access, rc);
	return rc;
E
Etienne Basset 已提交
3047 3048
}

3049 3050
/**
 * smack_sem_associate - Smack access check for sem
3051
 * @isp: the object
3052 3053 3054 3055
 * @semflg: access requested
 *
 * Returns 0 if current has the requested access, error code otherwise
 */
3056
static int smack_sem_associate(struct kern_ipc_perm *isp, int semflg)
3057 3058 3059 3060
{
	int may;

	may = smack_flags_to_may(semflg);
3061
	return smk_curacc_sem(isp, may);
3062 3063 3064 3065
}

/**
 * smack_sem_shmctl - Smack access check for sem
3066
 * @isp: the object
3067 3068 3069 3070
 * @cmd: what it wants to do
 *
 * Returns 0 if current has the requested access, error code otherwise
 */
3071
static int smack_sem_semctl(struct kern_ipc_perm *isp, int cmd)
3072 3073 3074 3075 3076 3077 3078 3079 3080 3081 3082
{
	int may;

	switch (cmd) {
	case GETPID:
	case GETNCNT:
	case GETZCNT:
	case GETVAL:
	case GETALL:
	case IPC_STAT:
	case SEM_STAT:
3083
	case SEM_STAT_ANY:
3084 3085 3086 3087 3088 3089 3090 3091 3092 3093 3094 3095 3096 3097 3098 3099 3100 3101
		may = MAY_READ;
		break;
	case SETVAL:
	case SETALL:
	case IPC_RMID:
	case IPC_SET:
		may = MAY_READWRITE;
		break;
	case IPC_INFO:
	case SEM_INFO:
		/*
		 * System level information
		 */
		return 0;
	default:
		return -EINVAL;
	}

3102
	return smk_curacc_sem(isp, may);
3103 3104 3105 3106
}

/**
 * smack_sem_semop - Smack checks of semaphore operations
3107
 * @isp: the object
3108 3109 3110 3111 3112 3113 3114 3115
 * @sops: unused
 * @nsops: unused
 * @alter: unused
 *
 * Treated as read and write in all cases.
 *
 * Returns 0 if access is allowed, error code otherwise
 */
3116
static int smack_sem_semop(struct kern_ipc_perm *isp, struct sembuf *sops,
3117 3118
			   unsigned nsops, int alter)
{
3119
	return smk_curacc_sem(isp, MAY_READWRITE);
3120 3121
}

E
Etienne Basset 已提交
3122 3123
/**
 * smk_curacc_msq : helper to check if current has access on msq
3124
 * @isp : the msq
E
Etienne Basset 已提交
3125 3126 3127 3128
 * @access : access requested
 *
 * return 0 if current has access, error otherwise
 */
3129
static int smk_curacc_msq(struct kern_ipc_perm *isp, int access)
E
Etienne Basset 已提交
3130
{
3131
	struct smack_known *msp = smack_of_ipc(isp);
E
Etienne Basset 已提交
3132
	struct smk_audit_info ad;
C
Casey Schaufler 已提交
3133
	int rc;
E
Etienne Basset 已提交
3134 3135 3136

#ifdef CONFIG_AUDIT
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
3137
	ad.a.u.ipc_id = isp->id;
E
Etienne Basset 已提交
3138
#endif
C
Casey Schaufler 已提交
3139 3140 3141
	rc = smk_curacc(msp, access, &ad);
	rc = smk_bu_current("msq", msp, access, rc);
	return rc;
E
Etienne Basset 已提交
3142 3143
}

3144 3145
/**
 * smack_msg_queue_associate - Smack access check for msg_queue
3146
 * @isp: the object
3147 3148 3149 3150
 * @msqflg: access requested
 *
 * Returns 0 if current has the requested access, error code otherwise
 */
3151
static int smack_msg_queue_associate(struct kern_ipc_perm *isp, int msqflg)
3152 3153 3154 3155
{
	int may;

	may = smack_flags_to_may(msqflg);
3156
	return smk_curacc_msq(isp, may);
3157 3158 3159 3160
}

/**
 * smack_msg_queue_msgctl - Smack access check for msg_queue
3161
 * @isp: the object
3162 3163 3164 3165
 * @cmd: what it wants to do
 *
 * Returns 0 if current has the requested access, error code otherwise
 */
3166
static int smack_msg_queue_msgctl(struct kern_ipc_perm *isp, int cmd)
3167 3168 3169 3170 3171 3172
{
	int may;

	switch (cmd) {
	case IPC_STAT:
	case MSG_STAT:
3173
	case MSG_STAT_ANY:
3174 3175 3176 3177 3178 3179 3180 3181 3182 3183 3184 3185 3186 3187 3188 3189
		may = MAY_READ;
		break;
	case IPC_SET:
	case IPC_RMID:
		may = MAY_READWRITE;
		break;
	case IPC_INFO:
	case MSG_INFO:
		/*
		 * System level information
		 */
		return 0;
	default:
		return -EINVAL;
	}

3190
	return smk_curacc_msq(isp, may);
3191 3192 3193 3194
}

/**
 * smack_msg_queue_msgsnd - Smack access check for msg_queue
3195
 * @isp: the object
3196 3197 3198 3199 3200
 * @msg: unused
 * @msqflg: access requested
 *
 * Returns 0 if current has the requested access, error code otherwise
 */
3201
static int smack_msg_queue_msgsnd(struct kern_ipc_perm *isp, struct msg_msg *msg,
3202 3203
				  int msqflg)
{
E
Etienne Basset 已提交
3204
	int may;
3205

E
Etienne Basset 已提交
3206
	may = smack_flags_to_may(msqflg);
3207
	return smk_curacc_msq(isp, may);
3208 3209 3210 3211
}

/**
 * smack_msg_queue_msgsnd - Smack access check for msg_queue
3212
 * @isp: the object
3213 3214 3215 3216 3217 3218 3219
 * @msg: unused
 * @target: unused
 * @type: unused
 * @mode: unused
 *
 * Returns 0 if current has read and write access, error code otherwise
 */
3220
static int smack_msg_queue_msgrcv(struct kern_ipc_perm *isp, struct msg_msg *msg,
3221 3222
			struct task_struct *target, long type, int mode)
{
3223
	return smk_curacc_msq(isp, MAY_READWRITE);
3224 3225 3226 3227 3228 3229 3230 3231 3232 3233 3234
}

/**
 * smack_ipc_permission - Smack access for ipc_permission()
 * @ipp: the object permissions
 * @flag: access requested
 *
 * Returns 0 if current has read and write access, error code otherwise
 */
static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag)
{
3235 3236
	struct smack_known **blob = smack_ipc(ipp);
	struct smack_known *iskp = *blob;
E
Etienne Basset 已提交
3237 3238
	int may = smack_flags_to_may(flag);
	struct smk_audit_info ad;
C
Casey Schaufler 已提交
3239
	int rc;
3240

E
Etienne Basset 已提交
3241 3242 3243 3244
#ifdef CONFIG_AUDIT
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
	ad.a.u.ipc_id = ipp->id;
#endif
3245 3246
	rc = smk_curacc(iskp, may, &ad);
	rc = smk_bu_current("svipc", iskp, may, rc);
C
Casey Schaufler 已提交
3247
	return rc;
3248 3249
}

3250 3251
/**
 * smack_ipc_getsecid - Extract smack security id
3252
 * @ipp: the object permissions
3253 3254 3255 3256
 * @secid: where result will be saved
 */
static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid)
{
3257 3258
	struct smack_known **blob = smack_ipc(ipp);
	struct smack_known *iskp = *blob;
3259

3260
	*secid = iskp->smk_secid;
3261 3262
}

3263 3264
/**
 * smack_d_instantiate - Make sure the blob is correct on an inode
3265
 * @opt_dentry: dentry where inode will be attached
3266 3267 3268 3269 3270 3271 3272 3273 3274
 * @inode: the object
 *
 * Set the inode's security blob if it hasn't been done already.
 */
static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
{
	struct super_block *sbp;
	struct superblock_smack *sbsp;
	struct inode_smack *isp;
3275 3276
	struct smack_known *skp;
	struct smack_known *ckp = smk_of_current();
3277
	struct smack_known *final;
3278 3279
	char trattr[TRANS_TRUE_SIZE];
	int transflag = 0;
C
Casey Schaufler 已提交
3280
	int rc;
3281 3282 3283 3284 3285
	struct dentry *dp;

	if (inode == NULL)
		return;

3286
	isp = smack_inode(inode);
3287 3288 3289 3290 3291 3292 3293 3294 3295 3296 3297 3298 3299 3300 3301 3302 3303

	mutex_lock(&isp->smk_lock);
	/*
	 * If the inode is already instantiated
	 * take the quick way out
	 */
	if (isp->smk_flags & SMK_INODE_INSTANT)
		goto unlockandout;

	sbp = inode->i_sb;
	sbsp = sbp->s_security;
	/*
	 * We're going to use the superblock default label
	 * if there's no label on the file.
	 */
	final = sbsp->smk_default;

C
Casey Schaufler 已提交
3304 3305 3306 3307 3308 3309 3310
	/*
	 * If this is the root inode the superblock
	 * may be in the process of initialization.
	 * If that is the case use the root value out
	 * of the superblock.
	 */
	if (opt_dentry->d_parent == opt_dentry) {
3311 3312
		switch (sbp->s_magic) {
		case CGROUP_SUPER_MAGIC:
3313
		case CGROUP2_SUPER_MAGIC:
3314 3315 3316 3317 3318
			/*
			 * The cgroup filesystem is never mounted,
			 * so there's no opportunity to set the mount
			 * options.
			 */
3319 3320
			sbsp->smk_root = &smack_known_star;
			sbsp->smk_default = &smack_known_star;
3321 3322 3323 3324 3325 3326 3327 3328 3329
			isp->smk_inode = sbsp->smk_root;
			break;
		case TMPFS_MAGIC:
			/*
			 * What about shmem/tmpfs anonymous files with dentry
			 * obtained from d_alloc_pseudo()?
			 */
			isp->smk_inode = smk_of_current();
			break;
3330 3331 3332
		case PIPEFS_MAGIC:
			isp->smk_inode = smk_of_current();
			break;
3333 3334 3335 3336 3337 3338 3339
		case SOCKFS_MAGIC:
			/*
			 * Socket access is controlled by the socket
			 * structures associated with the task involved.
			 */
			isp->smk_inode = &smack_known_star;
			break;
3340 3341 3342
		default:
			isp->smk_inode = sbsp->smk_root;
			break;
3343
		}
C
Casey Schaufler 已提交
3344 3345 3346 3347
		isp->smk_flags |= SMK_INODE_INSTANT;
		goto unlockandout;
	}

3348 3349 3350 3351 3352 3353 3354 3355
	/*
	 * This is pretty hackish.
	 * Casey says that we shouldn't have to do
	 * file system specific code, but it does help
	 * with keeping it simple.
	 */
	switch (sbp->s_magic) {
	case SMACK_MAGIC:
3356
	case CGROUP_SUPER_MAGIC:
3357
	case CGROUP2_SUPER_MAGIC:
3358
		/*
L
Lucas De Marchi 已提交
3359
		 * Casey says that it's a little embarrassing
3360 3361
		 * that the smack file system doesn't do
		 * extended attributes.
3362 3363
		 *
		 * Cgroupfs is special
3364
		 */
3365
		final = &smack_known_star;
3366 3367 3368 3369 3370 3371 3372
		break;
	case DEVPTS_SUPER_MAGIC:
		/*
		 * devpts seems content with the label of the task.
		 * Programs that change smack have to treat the
		 * pty with respect.
		 */
3373
		final = ckp;
3374 3375 3376 3377 3378 3379 3380 3381 3382 3383 3384 3385 3386
		break;
	case PROC_SUPER_MAGIC:
		/*
		 * Casey says procfs appears not to care.
		 * The superblock default suffices.
		 */
		break;
	case TMPFS_MAGIC:
		/*
		 * Device labels should come from the filesystem,
		 * but watch out, because they're volitile,
		 * getting recreated on every reboot.
		 */
3387
		final = &smack_known_star;
3388 3389 3390 3391 3392 3393
		/*
		 * If a smack value has been set we want to use it,
		 * but since tmpfs isn't giving us the opportunity
		 * to set mount options simulate setting the
		 * superblock default.
		 */
3394
		/* Fall through */
3395 3396 3397 3398
	default:
		/*
		 * This isn't an understood special case.
		 * Get the value from the xattr.
C
Casey Schaufler 已提交
3399 3400 3401 3402 3403 3404
		 */

		/*
		 * UNIX domain sockets use lower level socket data.
		 */
		if (S_ISSOCK(inode->i_mode)) {
3405
			final = &smack_known_star;
C
Casey Schaufler 已提交
3406 3407 3408
			break;
		}
		/*
3409 3410 3411 3412 3413
		 * No xattr support means, alas, no SMACK label.
		 * Use the aforeapplied default.
		 * It would be curious if the label of the task
		 * does not match that assigned.
		 */
3414 3415
		if (!(inode->i_opflags & IOP_XATTR))
		        break;
3416 3417 3418
		/*
		 * Get the dentry for xattr.
		 */
3419
		dp = dget(opt_dentry);
3420
		skp = smk_fetch(XATTR_NAME_SMACK, inode, dp);
3421
		if (!IS_ERR_OR_NULL(skp))
3422
			final = skp;
C
Casey Schaufler 已提交
3423 3424 3425 3426 3427 3428 3429 3430 3431 3432 3433 3434 3435 3436 3437 3438

		/*
		 * Transmuting directory
		 */
		if (S_ISDIR(inode->i_mode)) {
			/*
			 * If this is a new directory and the label was
			 * transmuted when the inode was initialized
			 * set the transmute attribute on the directory
			 * and mark the inode.
			 *
			 * If there is a transmute attribute on the
			 * directory mark the inode.
			 */
			if (isp->smk_flags & SMK_INODE_CHANGED) {
				isp->smk_flags &= ~SMK_INODE_CHANGED;
3439
				rc = __vfs_setxattr(dp, inode,
3440
					XATTR_NAME_SMACKTRANSMUTE,
C
Casey Schaufler 已提交
3441 3442 3443
					TRANS_TRUE, TRANS_TRUE_SIZE,
					0);
			} else {
3444
				rc = __vfs_getxattr(dp, inode,
C
Casey Schaufler 已提交
3445 3446 3447 3448 3449
					XATTR_NAME_SMACKTRANSMUTE, trattr,
					TRANS_TRUE_SIZE);
				if (rc >= 0 && strncmp(trattr, TRANS_TRUE,
						       TRANS_TRUE_SIZE) != 0)
					rc = -EINVAL;
3450
			}
C
Casey Schaufler 已提交
3451 3452
			if (rc >= 0)
				transflag = SMK_INODE_TRANSMUTE;
3453
		}
3454 3455 3456 3457 3458 3459 3460 3461
		/*
		 * Don't let the exec or mmap label be "*" or "@".
		 */
		skp = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp);
		if (IS_ERR(skp) || skp == &smack_known_star ||
		    skp == &smack_known_web)
			skp = NULL;
		isp->smk_task = skp;
3462

3463
		skp = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp);
3464 3465
		if (IS_ERR(skp) || skp == &smack_known_star ||
		    skp == &smack_known_web)
3466 3467
			skp = NULL;
		isp->smk_mmap = skp;
3468

3469 3470 3471 3472 3473
		dput(dp);
		break;
	}

	if (final == NULL)
3474
		isp->smk_inode = ckp;
3475 3476 3477
	else
		isp->smk_inode = final;

3478
	isp->smk_flags |= (SMK_INODE_INSTANT | transflag);
3479 3480 3481 3482 3483 3484 3485 3486 3487 3488 3489 3490 3491 3492 3493 3494 3495 3496

unlockandout:
	mutex_unlock(&isp->smk_lock);
	return;
}

/**
 * smack_getprocattr - Smack process attribute access
 * @p: the object task
 * @name: the name of the attribute in /proc/.../attr
 * @value: where to put the result
 *
 * Places a copy of the task Smack into value
 *
 * Returns the length of the smack label or an error code
 */
static int smack_getprocattr(struct task_struct *p, char *name, char **value)
{
3497
	struct smack_known *skp = smk_of_task_struct(p);
3498 3499 3500 3501 3502 3503
	char *cp;
	int slen;

	if (strcmp(name, "current") != 0)
		return -EINVAL;

3504
	cp = kstrdup(skp->smk_known, GFP_KERNEL);
3505 3506 3507 3508 3509 3510 3511 3512 3513 3514 3515 3516 3517 3518 3519 3520 3521 3522 3523
	if (cp == NULL)
		return -ENOMEM;

	slen = strlen(cp);
	*value = cp;
	return slen;
}

/**
 * smack_setprocattr - Smack process attribute setting
 * @name: the name of the attribute in /proc/.../attr
 * @value: the value to set
 * @size: the size of the value
 *
 * Sets the Smack value of the task. Only setting self
 * is permitted and only with privilege
 *
 * Returns the length of the smack label or an error code
 */
3524
static int smack_setprocattr(const char *name, void *value, size_t size)
3525
{
3526
	struct task_smack *tsp = smack_cred(current_cred());
D
David Howells 已提交
3527
	struct cred *new;
3528
	struct smack_known *skp;
3529 3530
	struct smack_known_list_elem *sklep;
	int rc;
3531

3532
	if (!smack_privileged(CAP_MAC_ADMIN) && list_empty(&tsp->smk_relabel))
3533 3534
		return -EPERM;

3535
	if (value == NULL || size == 0 || size >= SMK_LONGLABEL)
3536 3537 3538 3539 3540
		return -EINVAL;

	if (strcmp(name, "current") != 0)
		return -EINVAL;

3541
	skp = smk_import_entry(value, size);
3542 3543
	if (IS_ERR(skp))
		return PTR_ERR(skp);
3544

3545
	/*
3546 3547
	 * No process is ever allowed the web ("@") label
	 * and the star ("*") label.
3548
	 */
3549 3550
	if (skp == &smack_known_web || skp == &smack_known_star)
		return -EINVAL;
3551

3552 3553 3554 3555 3556 3557 3558 3559 3560 3561 3562
	if (!smack_privileged(CAP_MAC_ADMIN)) {
		rc = -EPERM;
		list_for_each_entry(sklep, &tsp->smk_relabel, list)
			if (sklep->smk_label == skp) {
				rc = 0;
				break;
			}
		if (rc)
			return rc;
	}

D
David Howells 已提交
3563
	new = prepare_creds();
3564
	if (new == NULL)
D
David Howells 已提交
3565
		return -ENOMEM;
3566

3567
	tsp = smack_cred(new);
3568
	tsp->smk_task = skp;
3569 3570 3571 3572
	/*
	 * process can change its label only once
	 */
	smk_destroy_label_list(&tsp->smk_relabel);
3573

D
David Howells 已提交
3574
	commit_creds(new);
3575 3576 3577 3578 3579
	return size;
}

/**
 * smack_unix_stream_connect - Smack access on UDS
3580 3581
 * @sock: one sock
 * @other: the other sock
3582 3583 3584 3585 3586
 * @newsk: unused
 *
 * Return 0 if a subject with the smack of sock could access
 * an object with the smack of other, otherwise an error code
 */
3587 3588
static int smack_unix_stream_connect(struct sock *sock,
				     struct sock *other, struct sock *newsk)
3589
{
3590
	struct smack_known *skp;
3591
	struct smack_known *okp;
J
James Morris 已提交
3592 3593
	struct socket_smack *ssp = sock->sk_security;
	struct socket_smack *osp = other->sk_security;
3594
	struct socket_smack *nsp = newsk->sk_security;
E
Etienne Basset 已提交
3595
	struct smk_audit_info ad;
C
Casey Schaufler 已提交
3596
	int rc = 0;
3597 3598 3599
#ifdef CONFIG_AUDIT
	struct lsm_network_audit net;
#endif
C
Casey Schaufler 已提交
3600

3601 3602
	if (!smack_privileged(CAP_MAC_OVERRIDE)) {
		skp = ssp->smk_out;
3603
		okp = osp->smk_in;
3604 3605 3606 3607
#ifdef CONFIG_AUDIT
		smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
		smk_ad_setfield_u_net_sk(&ad, other);
#endif
3608 3609
		rc = smk_access(skp, okp, MAY_WRITE, &ad);
		rc = smk_bu_note("UDS connect", skp, okp, MAY_WRITE, rc);
C
Casey Schaufler 已提交
3610
		if (rc == 0) {
3611 3612
			okp = osp->smk_out;
			skp = ssp->smk_in;
3613
			rc = smk_access(okp, skp, MAY_WRITE, &ad);
3614
			rc = smk_bu_note("UDS connect", okp, skp,
C
Casey Schaufler 已提交
3615 3616
						MAY_WRITE, rc);
		}
3617
	}
C
Casey Schaufler 已提交
3618

3619 3620 3621 3622
	/*
	 * Cross reference the peer labels for SO_PEERSEC.
	 */
	if (rc == 0) {
3623 3624
		nsp->smk_packet = ssp->smk_out;
		ssp->smk_packet = osp->smk_out;
3625 3626
	}

C
Casey Schaufler 已提交
3627
	return rc;
3628 3629 3630 3631 3632 3633 3634 3635 3636 3637 3638 3639
}

/**
 * smack_unix_may_send - Smack access on UDS
 * @sock: one socket
 * @other: the other socket
 *
 * Return 0 if a subject with the smack of sock could access
 * an object with the smack of other, otherwise an error code
 */
static int smack_unix_may_send(struct socket *sock, struct socket *other)
{
C
Casey Schaufler 已提交
3640 3641
	struct socket_smack *ssp = sock->sk->sk_security;
	struct socket_smack *osp = other->sk->sk_security;
E
Etienne Basset 已提交
3642
	struct smk_audit_info ad;
C
Casey Schaufler 已提交
3643
	int rc;
3644

3645 3646 3647
#ifdef CONFIG_AUDIT
	struct lsm_network_audit net;

3648
	smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
E
Etienne Basset 已提交
3649
	smk_ad_setfield_u_net_sk(&ad, other->sk);
3650
#endif
C
Casey Schaufler 已提交
3651

3652 3653
	if (smack_privileged(CAP_MAC_OVERRIDE))
		return 0;
C
Casey Schaufler 已提交
3654

3655 3656
	rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad);
	rc = smk_bu_note("UDS send", ssp->smk_out, osp->smk_in, MAY_WRITE, rc);
C
Casey Schaufler 已提交
3657
	return rc;
3658 3659
}

3660 3661 3662
/**
 * smack_socket_sendmsg - Smack check based on destination host
 * @sock: the socket
3663
 * @msg: the message
3664 3665
 * @size: the size of the message
 *
3666 3667 3668
 * Return 0 if the current subject can write to the destination host.
 * For IPv4 this is only a question if the destination is a single label host.
 * For IPv6 this is a check against the label of the port.
3669 3670 3671 3672 3673
 */
static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
				int size)
{
	struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name;
C
Casey Schaufler 已提交
3674
#if IS_ENABLED(CONFIG_IPV6)
3675
	struct sockaddr_in6 *sap = (struct sockaddr_in6 *) msg->msg_name;
C
Casey Schaufler 已提交
3676 3677 3678 3679 3680
#endif
#ifdef SMACK_IPV6_SECMARK_LABELING
	struct socket_smack *ssp = sock->sk->sk_security;
	struct smack_known *rsp;
#endif
3681
	int rc = 0;
3682 3683 3684 3685

	/*
	 * Perfectly reasonable for this to be NULL
	 */
3686
	if (sip == NULL)
3687 3688
		return 0;

3689
	switch (sock->sk->sk_family) {
3690
	case AF_INET:
3691 3692 3693
		if (msg->msg_namelen < sizeof(struct sockaddr_in) ||
		    sip->sin_family != AF_INET)
			return -EINVAL;
3694 3695
		rc = smack_netlabel_send(sock->sk, sip);
		break;
3696
#if IS_ENABLED(CONFIG_IPV6)
3697
	case AF_INET6:
3698 3699 3700
		if (msg->msg_namelen < SIN6_LEN_RFC2133 ||
		    sap->sin6_family != AF_INET6)
			return -EINVAL;
C
Casey Schaufler 已提交
3701 3702 3703 3704 3705 3706 3707
#ifdef SMACK_IPV6_SECMARK_LABELING
		rsp = smack_ipv6host_label(sap);
		if (rsp != NULL)
			rc = smk_ipv6_check(ssp->smk_out, rsp, sap,
						SMK_CONNECTING);
#endif
#ifdef SMACK_IPV6_PORT_LABELING
3708
		rc = smk_ipv6_port_check(sock->sk, sap, SMK_SENDING);
C
Casey Schaufler 已提交
3709
#endif
3710
#endif /* IS_ENABLED(CONFIG_IPV6) */
3711 3712 3713
		break;
	}
	return rc;
3714 3715
}

3716
/**
3717
 * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack
3718
 * @sap: netlabel secattr
3719
 * @ssp: socket security information
3720
 *
3721
 * Returns a pointer to a Smack label entry found on the label list.
3722
 */
3723 3724
static struct smack_known *smack_from_secattr(struct netlbl_lsm_secattr *sap,
						struct socket_smack *ssp)
3725
{
3726
	struct smack_known *skp;
3727
	int found = 0;
C
Casey Schaufler 已提交
3728 3729
	int acat;
	int kcat;
3730

3731
	if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) {
3732
		/*
3733
		 * Looks like a CIPSO packet.
3734 3735 3736
		 * If there are flags but no level netlabel isn't
		 * behaving the way we expect it to.
		 *
3737
		 * Look it up in the label table
3738 3739 3740 3741
		 * Without guidance regarding the smack value
		 * for the packet fall back on the network
		 * ambient value.
		 */
3742
		rcu_read_lock();
3743
		list_for_each_entry_rcu(skp, &smack_known_list, list) {
3744
			if (sap->attr.mls.lvl != skp->smk_netlabel.attr.mls.lvl)
3745
				continue;
C
Casey Schaufler 已提交
3746 3747 3748 3749 3750 3751 3752 3753 3754 3755
			/*
			 * Compare the catsets. Use the netlbl APIs.
			 */
			if ((sap->flags & NETLBL_SECATTR_MLS_CAT) == 0) {
				if ((skp->smk_netlabel.flags &
				     NETLBL_SECATTR_MLS_CAT) == 0)
					found = 1;
				break;
			}
			for (acat = -1, kcat = -1; acat == kcat; ) {
3756 3757 3758
				acat = netlbl_catmap_walk(sap->attr.mls.cat,
							  acat + 1);
				kcat = netlbl_catmap_walk(
C
Casey Schaufler 已提交
3759 3760 3761 3762 3763 3764 3765 3766 3767
					skp->smk_netlabel.attr.mls.cat,
					kcat + 1);
				if (acat < 0 || kcat < 0)
					break;
			}
			if (acat == kcat) {
				found = 1;
				break;
			}
3768
		}
3769 3770 3771
		rcu_read_unlock();

		if (found)
3772
			return skp;
3773

3774
		if (ssp != NULL && ssp->smk_in == &smack_known_star)
3775 3776
			return &smack_known_web;
		return &smack_known_star;
3777
	}
3778
	if ((sap->flags & NETLBL_SECATTR_SECID) != 0)
3779 3780 3781
		/*
		 * Looks like a fallback, which gives us a secid.
		 */
3782
		return smack_from_secid(sap->attr.secid);
3783
	/*
3784 3785 3786
	 * Without guidance regarding the smack value
	 * for the packet fall back on the network
	 * ambient value.
3787
	 */
3788
	return smack_net_ambient;
3789 3790
}

3791
#if IS_ENABLED(CONFIG_IPV6)
3792
static int smk_skb_to_addr_ipv6(struct sk_buff *skb, struct sockaddr_in6 *sip)
3793 3794 3795 3796 3797 3798 3799 3800 3801 3802 3803 3804 3805 3806 3807 3808 3809 3810 3811 3812 3813 3814 3815 3816 3817 3818 3819 3820 3821 3822 3823 3824 3825
{
	u8 nexthdr;
	int offset;
	int proto = -EINVAL;
	struct ipv6hdr _ipv6h;
	struct ipv6hdr *ip6;
	__be16 frag_off;
	struct tcphdr _tcph, *th;
	struct udphdr _udph, *uh;
	struct dccp_hdr _dccph, *dh;

	sip->sin6_port = 0;

	offset = skb_network_offset(skb);
	ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
	if (ip6 == NULL)
		return -EINVAL;
	sip->sin6_addr = ip6->saddr;

	nexthdr = ip6->nexthdr;
	offset += sizeof(_ipv6h);
	offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);
	if (offset < 0)
		return -EINVAL;

	proto = nexthdr;
	switch (proto) {
	case IPPROTO_TCP:
		th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
		if (th != NULL)
			sip->sin6_port = th->source;
		break;
	case IPPROTO_UDP:
3826
	case IPPROTO_UDPLITE:
3827 3828 3829 3830 3831 3832 3833 3834 3835 3836 3837 3838
		uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
		if (uh != NULL)
			sip->sin6_port = uh->source;
		break;
	case IPPROTO_DCCP:
		dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
		if (dh != NULL)
			sip->sin6_port = dh->dccph_sport;
		break;
	}
	return proto;
}
3839
#endif /* CONFIG_IPV6 */
3840

3841 3842 3843 3844 3845 3846 3847 3848 3849 3850 3851
/**
 * smack_socket_sock_rcv_skb - Smack packet delivery access check
 * @sk: socket
 * @skb: packet
 *
 * Returns 0 if the packet should be delivered, an error code otherwise
 */
static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
	struct netlbl_lsm_secattr secattr;
	struct socket_smack *ssp = sk->sk_security;
3852
	struct smack_known *skp = NULL;
3853
	int rc = 0;
E
Etienne Basset 已提交
3854
	struct smk_audit_info ad;
3855
	u16 family = sk->sk_family;
3856
#ifdef CONFIG_AUDIT
3857
	struct lsm_network_audit net;
3858
#endif
3859 3860 3861
#if IS_ENABLED(CONFIG_IPV6)
	struct sockaddr_in6 sadd;
	int proto;
3862 3863 3864

	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
		family = PF_INET;
3865 3866
#endif /* CONFIG_IPV6 */

3867
	switch (family) {
3868
	case PF_INET:
3869 3870 3871 3872 3873 3874 3875 3876 3877 3878 3879
#ifdef CONFIG_SECURITY_SMACK_NETFILTER
		/*
		 * If there is a secmark use it rather than the CIPSO label.
		 * If there is no secmark fall back to CIPSO.
		 * The secmark is assumed to reflect policy better.
		 */
		if (skb && skb->secmark != 0) {
			skp = smack_from_secid(skb->secmark);
			goto access_check;
		}
#endif /* CONFIG_SECURITY_SMACK_NETFILTER */
3880 3881 3882 3883
		/*
		 * Translate what netlabel gave us.
		 */
		netlbl_secattr_init(&secattr);
3884

3885
		rc = netlbl_skbuff_getattr(skb, family, &secattr);
3886
		if (rc == 0)
3887
			skp = smack_from_secattr(&secattr, ssp);
3888
		else
3889
			skp = smack_net_ambient;
3890

3891
		netlbl_secattr_destroy(&secattr);
3892

3893 3894 3895
#ifdef CONFIG_SECURITY_SMACK_NETFILTER
access_check:
#endif
E
Etienne Basset 已提交
3896
#ifdef CONFIG_AUDIT
3897
		smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
3898
		ad.a.u.net->family = family;
3899 3900
		ad.a.u.net->netif = skb->skb_iif;
		ipv4_skb_to_auditdata(skb, &ad.a, NULL);
E
Etienne Basset 已提交
3901
#endif
3902 3903 3904 3905 3906 3907
		/*
		 * Receiving a packet requires that the other end
		 * be able to write here. Read access is not required.
		 * This is the simplist possible security model
		 * for networking.
		 */
3908 3909
		rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad);
		rc = smk_bu_note("IPv4 delivery", skp, ssp->smk_in,
C
Casey Schaufler 已提交
3910
					MAY_WRITE, rc);
3911
		if (rc != 0)
3912
			netlbl_skbuff_err(skb, family, rc, 0);
3913
		break;
3914
#if IS_ENABLED(CONFIG_IPV6)
3915
	case PF_INET6:
3916
		proto = smk_skb_to_addr_ipv6(skb, &sadd);
3917 3918
		if (proto != IPPROTO_UDP && proto != IPPROTO_UDPLITE &&
		    proto != IPPROTO_TCP && proto != IPPROTO_DCCP)
3919
			break;
C
Casey Schaufler 已提交
3920
#ifdef SMACK_IPV6_SECMARK_LABELING
3921 3922
		if (skb && skb->secmark != 0)
			skp = smack_from_secid(skb->secmark);
3923 3924
		else if (smk_ipv6_localhost(&sadd))
			break;
3925
		else
C
Casey Schaufler 已提交
3926 3927
			skp = smack_ipv6host_label(&sadd);
		if (skp == NULL)
3928 3929 3930
			skp = smack_net_ambient;
#ifdef CONFIG_AUDIT
		smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
3931
		ad.a.u.net->family = family;
3932 3933 3934 3935 3936 3937
		ad.a.u.net->netif = skb->skb_iif;
		ipv6_skb_to_auditdata(skb, &ad.a, NULL);
#endif /* CONFIG_AUDIT */
		rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad);
		rc = smk_bu_note("IPv6 delivery", skp, ssp->smk_in,
					MAY_WRITE, rc);
C
Casey Schaufler 已提交
3938 3939
#endif /* SMACK_IPV6_SECMARK_LABELING */
#ifdef SMACK_IPV6_PORT_LABELING
3940
		rc = smk_ipv6_port_check(sk, &sadd, SMK_RECEIVING);
C
Casey Schaufler 已提交
3941
#endif /* SMACK_IPV6_PORT_LABELING */
3942 3943 3944
		if (rc != 0)
			icmpv6_send(skb, ICMPV6_DEST_UNREACH,
					ICMPV6_ADM_PROHIBITED, 0);
3945
		break;
3946
#endif /* CONFIG_IPV6 */
3947
	}
3948

3949
	return rc;
3950 3951 3952 3953 3954 3955 3956
}

/**
 * smack_socket_getpeersec_stream - pull in packet label
 * @sock: the socket
 * @optval: user's destination
 * @optlen: size thereof
3957
 * @len: max thereof
3958 3959 3960 3961 3962 3963 3964 3965
 *
 * returns zero on success, an error code otherwise
 */
static int smack_socket_getpeersec_stream(struct socket *sock,
					  char __user *optval,
					  int __user *optlen, unsigned len)
{
	struct socket_smack *ssp;
3966 3967
	char *rcp = "";
	int slen = 1;
3968 3969 3970
	int rc = 0;

	ssp = sock->sk->sk_security;
3971
	if (ssp->smk_packet != NULL) {
3972
		rcp = ssp->smk_packet->smk_known;
3973 3974
		slen = strlen(rcp) + 1;
	}
3975 3976 3977

	if (slen > len)
		rc = -ERANGE;
3978
	else if (copy_to_user(optval, rcp, slen) != 0)
3979 3980 3981 3982 3983 3984 3985 3986 3987 3988 3989
		rc = -EFAULT;

	if (put_user(slen, optlen) != 0)
		rc = -EFAULT;

	return rc;
}


/**
 * smack_socket_getpeersec_dgram - pull in packet label
C
Casey Schaufler 已提交
3990
 * @sock: the peer socket
3991 3992 3993 3994 3995 3996 3997 3998 3999 4000
 * @skb: packet data
 * @secid: pointer to where to put the secid of the packet
 *
 * Sets the netlabel socket state on sk from parent
 */
static int smack_socket_getpeersec_dgram(struct socket *sock,
					 struct sk_buff *skb, u32 *secid)

{
	struct netlbl_lsm_secattr secattr;
4001
	struct socket_smack *ssp = NULL;
4002
	struct smack_known *skp;
C
Casey Schaufler 已提交
4003 4004
	int family = PF_UNSPEC;
	u32 s = 0;	/* 0 is the invalid secid */
4005 4006
	int rc;

C
Casey Schaufler 已提交
4007 4008 4009
	if (skb != NULL) {
		if (skb->protocol == htons(ETH_P_IP))
			family = PF_INET;
4010
#if IS_ENABLED(CONFIG_IPV6)
C
Casey Schaufler 已提交
4011 4012
		else if (skb->protocol == htons(ETH_P_IPV6))
			family = PF_INET6;
4013
#endif /* CONFIG_IPV6 */
4014
	}
C
Casey Schaufler 已提交
4015 4016
	if (family == PF_UNSPEC && sock != NULL)
		family = sock->sk->sk_family;
4017

4018 4019
	switch (family) {
	case PF_UNIX:
4020
		ssp = sock->sk->sk_security;
4021
		s = ssp->smk_out->smk_secid;
4022 4023 4024 4025 4026 4027 4028
		break;
	case PF_INET:
#ifdef CONFIG_SECURITY_SMACK_NETFILTER
		s = skb->secmark;
		if (s != 0)
			break;
#endif
C
Casey Schaufler 已提交
4029 4030 4031
		/*
		 * Translate what netlabel gave us.
		 */
4032 4033
		if (sock != NULL && sock->sk != NULL)
			ssp = sock->sk->sk_security;
C
Casey Schaufler 已提交
4034 4035 4036
		netlbl_secattr_init(&secattr);
		rc = netlbl_skbuff_getattr(skb, family, &secattr);
		if (rc == 0) {
4037 4038
			skp = smack_from_secattr(&secattr, ssp);
			s = skp->smk_secid;
C
Casey Schaufler 已提交
4039 4040
		}
		netlbl_secattr_destroy(&secattr);
4041 4042
		break;
	case PF_INET6:
C
Casey Schaufler 已提交
4043
#ifdef SMACK_IPV6_SECMARK_LABELING
4044
		s = skb->secmark;
C
Casey Schaufler 已提交
4045
#endif
4046
		break;
C
Casey Schaufler 已提交
4047 4048
	}
	*secid = s;
4049 4050 4051 4052 4053 4054
	if (s == 0)
		return -EINVAL;
	return 0;
}

/**
4055 4056 4057
 * smack_sock_graft - Initialize a newly created socket with an existing sock
 * @sk: child sock
 * @parent: parent socket
4058
 *
4059 4060
 * Set the smk_{in,out} state of an existing sock based on the process that
 * is creating the new socket.
4061 4062 4063 4064
 */
static void smack_sock_graft(struct sock *sk, struct socket *parent)
{
	struct socket_smack *ssp;
4065
	struct smack_known *skp = smk_of_current();
4066

4067 4068
	if (sk == NULL ||
	    (sk->sk_family != PF_INET && sk->sk_family != PF_INET6))
4069 4070 4071
		return;

	ssp = sk->sk_security;
4072
	ssp->smk_in = skp;
4073
	ssp->smk_out = skp;
4074
	/* cssp->smk_packet is already set in smack_inet_csk_clone() */
4075 4076 4077 4078 4079 4080 4081 4082 4083 4084 4085 4086 4087 4088
}

/**
 * smack_inet_conn_request - Smack access check on connect
 * @sk: socket involved
 * @skb: packet
 * @req: unused
 *
 * Returns 0 if a task with the packet label could write to
 * the socket, otherwise an error code
 */
static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
				   struct request_sock *req)
{
4089
	u16 family = sk->sk_family;
4090
	struct smack_known *skp;
4091
	struct socket_smack *ssp = sk->sk_security;
4092 4093 4094
	struct netlbl_lsm_secattr secattr;
	struct sockaddr_in addr;
	struct iphdr *hdr;
4095
	struct smack_known *hskp;
4096
	int rc;
E
Etienne Basset 已提交
4097
	struct smk_audit_info ad;
4098
#ifdef CONFIG_AUDIT
4099
	struct lsm_network_audit net;
4100
#endif
4101

4102
#if IS_ENABLED(CONFIG_IPV6)
4103 4104 4105 4106 4107 4108 4109 4110 4111 4112 4113
	if (family == PF_INET6) {
		/*
		 * Handle mapped IPv4 packets arriving
		 * via IPv6 sockets. Don't set up netlabel
		 * processing on IPv6.
		 */
		if (skb->protocol == htons(ETH_P_IP))
			family = PF_INET;
		else
			return 0;
	}
4114
#endif /* CONFIG_IPV6 */
4115

C
Casey Schaufler 已提交
4116 4117 4118 4119 4120 4121 4122 4123 4124 4125 4126 4127
#ifdef CONFIG_SECURITY_SMACK_NETFILTER
	/*
	 * If there is a secmark use it rather than the CIPSO label.
	 * If there is no secmark fall back to CIPSO.
	 * The secmark is assumed to reflect policy better.
	 */
	if (skb && skb->secmark != 0) {
		skp = smack_from_secid(skb->secmark);
		goto access_check;
	}
#endif /* CONFIG_SECURITY_SMACK_NETFILTER */

4128 4129
	netlbl_secattr_init(&secattr);
	rc = netlbl_skbuff_getattr(skb, family, &secattr);
4130
	if (rc == 0)
4131
		skp = smack_from_secattr(&secattr, ssp);
4132
	else
4133
		skp = &smack_known_huh;
4134 4135
	netlbl_secattr_destroy(&secattr);

C
Casey Schaufler 已提交
4136 4137 4138 4139
#ifdef CONFIG_SECURITY_SMACK_NETFILTER
access_check:
#endif

E
Etienne Basset 已提交
4140
#ifdef CONFIG_AUDIT
4141 4142 4143
	smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
	ad.a.u.net->family = family;
	ad.a.u.net->netif = skb->skb_iif;
E
Etienne Basset 已提交
4144 4145
	ipv4_skb_to_auditdata(skb, &ad.a, NULL);
#endif
4146
	/*
4147 4148
	 * Receiving a packet requires that the other end be able to write
	 * here. Read access is not required.
4149
	 */
4150 4151
	rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad);
	rc = smk_bu_note("IPv4 connect", skp, ssp->smk_in, MAY_WRITE, rc);
4152 4153 4154 4155 4156 4157 4158
	if (rc != 0)
		return rc;

	/*
	 * Save the peer's label in the request_sock so we can later setup
	 * smk_packet in the child socket so that SO_PEERCRED can report it.
	 */
4159
	req->peer_secid = skp->smk_secid;
4160 4161 4162 4163

	/*
	 * We need to decide if we want to label the incoming connection here
	 * if we do we only need to label the request_sock and the stack will
L
Lucas De Marchi 已提交
4164
	 * propagate the wire-label to the sock when it is created.
4165 4166 4167 4168
	 */
	hdr = ip_hdr(skb);
	addr.sin_addr.s_addr = hdr->saddr;
	rcu_read_lock();
C
Casey Schaufler 已提交
4169
	hskp = smack_ipv4host_label(&addr);
4170 4171
	rcu_read_unlock();

4172
	if (hskp == NULL)
4173
		rc = netlbl_req_setattr(req, &skp->smk_netlabel);
4174
	else
4175
		netlbl_req_delattr(req);
4176 4177 4178 4179

	return rc;
}

4180 4181 4182 4183 4184 4185 4186 4187 4188 4189 4190
/**
 * smack_inet_csk_clone - Copy the connection information to the new socket
 * @sk: the new socket
 * @req: the connection's request_sock
 *
 * Transfer the connection's peer label to the newly created socket.
 */
static void smack_inet_csk_clone(struct sock *sk,
				 const struct request_sock *req)
{
	struct socket_smack *ssp = sk->sk_security;
4191
	struct smack_known *skp;
4192

4193 4194
	if (req->peer_secid != 0) {
		skp = smack_from_secid(req->peer_secid);
4195
		ssp->smk_packet = skp;
4196
	} else
4197
		ssp->smk_packet = NULL;
4198 4199
}

4200 4201 4202 4203 4204 4205 4206 4207 4208 4209 4210 4211
/*
 * Key management security hooks
 *
 * Casey has not tested key support very heavily.
 * The permission check is most likely too restrictive.
 * If you care about keys please have a look.
 */
#ifdef CONFIG_KEYS

/**
 * smack_key_alloc - Set the key security blob
 * @key: object
D
David Howells 已提交
4212
 * @cred: the credentials to use
4213 4214 4215 4216 4217 4218
 * @flags: unused
 *
 * No allocation required
 *
 * Returns 0
 */
D
David Howells 已提交
4219
static int smack_key_alloc(struct key *key, const struct cred *cred,
4220 4221
			   unsigned long flags)
{
4222
	struct smack_known *skp = smk_of_task(smack_cred(cred));
4223

4224
	key->security = skp;
4225 4226 4227 4228 4229 4230 4231 4232 4233 4234 4235 4236 4237 4238
	return 0;
}

/**
 * smack_key_free - Clear the key security blob
 * @key: the object
 *
 * Clear the blob pointer
 */
static void smack_key_free(struct key *key)
{
	key->security = NULL;
}

4239
/**
4240 4241
 * smack_key_permission - Smack access on a key
 * @key_ref: gets to the object
D
David Howells 已提交
4242
 * @cred: the credentials to use
4243
 * @perm: requested key permissions
4244 4245 4246 4247 4248
 *
 * Return 0 if the task has read and write to the object,
 * an error code otherwise
 */
static int smack_key_permission(key_ref_t key_ref,
4249
				const struct cred *cred, unsigned perm)
4250 4251
{
	struct key *keyp;
E
Etienne Basset 已提交
4252
	struct smk_audit_info ad;
4253
	struct smack_known *tkp = smk_of_task(smack_cred(cred));
4254
	int request = 0;
C
Casey Schaufler 已提交
4255
	int rc;
4256

4257 4258 4259 4260 4261 4262
	/*
	 * Validate requested permissions
	 */
	if (perm & ~KEY_NEED_ALL)
		return -EINVAL;

4263 4264 4265 4266 4267 4268 4269 4270 4271 4272 4273 4274
	keyp = key_ref_to_ptr(key_ref);
	if (keyp == NULL)
		return -EINVAL;
	/*
	 * If the key hasn't been initialized give it access so that
	 * it may do so.
	 */
	if (keyp->security == NULL)
		return 0;
	/*
	 * This should not occur
	 */
4275
	if (tkp == NULL)
4276
		return -EACCES;
4277 4278 4279 4280

	if (smack_privileged_cred(CAP_MAC_OVERRIDE, cred))
		return 0;

E
Etienne Basset 已提交
4281 4282 4283 4284 4285
#ifdef CONFIG_AUDIT
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY);
	ad.a.u.key_struct.key = keyp->serial;
	ad.a.u.key_struct.key_desc = keyp->description;
#endif
4286 4287
	if (perm & (KEY_NEED_READ | KEY_NEED_SEARCH | KEY_NEED_VIEW))
		request |= MAY_READ;
4288 4289
	if (perm & (KEY_NEED_WRITE | KEY_NEED_LINK | KEY_NEED_SETSEC |
		    KEY_NEED_INVAL | KEY_NEED_REVOKE | KEY_NEED_CLEAR))
4290
		request |= MAY_WRITE;
C
Casey Schaufler 已提交
4291 4292 4293
	rc = smk_access(tkp, keyp->security, request, &ad);
	rc = smk_bu_note("key access", tkp, keyp->security, request, rc);
	return rc;
4294
}
4295 4296 4297 4298 4299 4300 4301 4302 4303 4304 4305 4306 4307 4308 4309 4310 4311 4312 4313 4314 4315 4316 4317 4318 4319 4320 4321 4322 4323 4324

/*
 * smack_key_getsecurity - Smack label tagging the key
 * @key points to the key to be queried
 * @_buffer points to a pointer that should be set to point to the
 * resulting string (if no label or an error occurs).
 * Return the length of the string (including terminating NUL) or -ve if
 * an error.
 * May also return 0 (and a NULL buffer pointer) if there is no label.
 */
static int smack_key_getsecurity(struct key *key, char **_buffer)
{
	struct smack_known *skp = key->security;
	size_t length;
	char *copy;

	if (key->security == NULL) {
		*_buffer = NULL;
		return 0;
	}

	copy = kstrdup(skp->smk_known, GFP_KERNEL);
	if (copy == NULL)
		return -ENOMEM;
	length = strlen(copy) + 1;

	*_buffer = copy;
	return length;
}

4325 4326
#endif /* CONFIG_KEYS */

4327 4328 4329 4330 4331 4332 4333 4334 4335 4336 4337 4338 4339 4340 4341 4342 4343 4344 4345 4346 4347 4348 4349 4350 4351 4352 4353
/*
 * Smack Audit hooks
 *
 * Audit requires a unique representation of each Smack specific
 * rule. This unique representation is used to distinguish the
 * object to be audited from remaining kernel objects and also
 * works as a glue between the audit hooks.
 *
 * Since repository entries are added but never deleted, we'll use
 * the smack_known label address related to the given audit rule as
 * the needed unique representation. This also better fits the smack
 * model where nearly everything is a label.
 */
#ifdef CONFIG_AUDIT

/**
 * smack_audit_rule_init - Initialize a smack audit rule
 * @field: audit rule fields given from user-space (audit.h)
 * @op: required testing operator (=, !=, >, <, ...)
 * @rulestr: smack label to be audited
 * @vrule: pointer to save our own audit rule representation
 *
 * Prepare to audit cases where (@field @op @rulestr) is true.
 * The label to be audited is created if necessay.
 */
static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
{
4354
	struct smack_known *skp;
4355 4356 4357 4358 4359 4360
	char **rule = (char **)vrule;
	*rule = NULL;

	if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
		return -EINVAL;

4361
	if (op != Audit_equal && op != Audit_not_equal)
4362 4363
		return -EINVAL;

4364
	skp = smk_import_entry(rulestr, 0);
4365 4366 4367 4368
	if (IS_ERR(skp))
		return PTR_ERR(skp);

	*rule = skp->smk_known;
4369 4370 4371 4372 4373 4374 4375 4376 4377 4378 4379 4380 4381 4382 4383 4384 4385 4386 4387 4388 4389 4390 4391 4392 4393 4394 4395 4396 4397 4398 4399 4400 4401 4402 4403 4404 4405

	return 0;
}

/**
 * smack_audit_rule_known - Distinguish Smack audit rules
 * @krule: rule of interest, in Audit kernel representation format
 *
 * This is used to filter Smack rules from remaining Audit ones.
 * If it's proved that this rule belongs to us, the
 * audit_rule_match hook will be called to do the final judgement.
 */
static int smack_audit_rule_known(struct audit_krule *krule)
{
	struct audit_field *f;
	int i;

	for (i = 0; i < krule->field_count; i++) {
		f = &krule->fields[i];

		if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER)
			return 1;
	}

	return 0;
}

/**
 * smack_audit_rule_match - Audit given object ?
 * @secid: security id for identifying the object to test
 * @field: audit rule flags given from user-space
 * @op: required testing operator
 * @vrule: smack internal rule presentation
 *
 * The core Audit hook. It's used to take the decision of
 * whether to audit or not to audit a given object.
 */
4406
static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule)
4407
{
4408
	struct smack_known *skp;
4409 4410
	char *rule = vrule;

4411 4412
	if (unlikely(!rule)) {
		WARN_ONCE(1, "Smack: missing rule\n");
4413 4414 4415 4416 4417 4418
		return -ENOENT;
	}

	if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
		return 0;

4419
	skp = smack_from_secid(secid);
4420 4421 4422 4423 4424 4425

	/*
	 * No need to do string comparisons. If a match occurs,
	 * both pointers will point to the same smack_known
	 * label.
	 */
4426
	if (op == Audit_equal)
4427
		return (rule == skp->smk_known);
4428
	if (op == Audit_not_equal)
4429
		return (rule != skp->smk_known);
4430 4431 4432 4433

	return 0;
}

C
Casey Schaufler 已提交
4434 4435
/*
 * There is no need for a smack_audit_rule_free hook.
4436 4437 4438 4439 4440
 * No memory was allocated.
 */

#endif /* CONFIG_AUDIT */

4441 4442 4443 4444 4445 4446 4447 4448 4449 4450
/**
 * smack_ismaclabel - check if xattr @name references a smack MAC label
 * @name: Full xattr name to check.
 */
static int smack_ismaclabel(const char *name)
{
	return (strcmp(name, XATTR_SMACK_SUFFIX) == 0);
}


4451
/**
4452 4453 4454 4455 4456 4457 4458 4459 4460
 * smack_secid_to_secctx - return the smack label for a secid
 * @secid: incoming integer
 * @secdata: destination
 * @seclen: how long it is
 *
 * Exists for networking code.
 */
static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
{
4461
	struct smack_known *skp = smack_from_secid(secid);
4462

4463
	if (secdata)
4464 4465
		*secdata = skp->smk_known;
	*seclen = strlen(skp->smk_known);
4466 4467 4468
	return 0;
}

4469
/**
4470 4471 4472 4473 4474 4475 4476
 * smack_secctx_to_secid - return the secid for a smack label
 * @secdata: smack label
 * @seclen: how long result is
 * @secid: outgoing integer
 *
 * Exists for audit and networking code.
 */
4477
static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
4478
{
4479 4480 4481 4482 4483 4484
	struct smack_known *skp = smk_find_entry(secdata);

	if (skp)
		*secid = skp->smk_secid;
	else
		*secid = 0;
4485 4486 4487
	return 0;
}

C
Casey Schaufler 已提交
4488 4489 4490 4491
/*
 * There used to be a smack_release_secctx hook
 * that did nothing back when hooks were in a vector.
 * Now that there's a list such a hook adds cost.
4492 4493
 */

4494 4495 4496 4497 4498 4499 4500 4501 4502 4503 4504 4505
static int smack_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
{
	return smack_inode_setsecurity(inode, XATTR_SMACK_SUFFIX, ctx, ctxlen, 0);
}

static int smack_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
{
	return __vfs_setxattr_noperm(dentry, XATTR_NAME_SMACK, ctx, ctxlen, 0);
}

static int smack_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
{
4506
	struct smack_known *skp = smk_of_inode(inode);
4507

4508 4509
	*ctx = skp->smk_known;
	*ctxlen = strlen(skp->smk_known);
4510 4511 4512
	return 0;
}

4513 4514 4515 4516 4517 4518 4519 4520 4521 4522 4523 4524 4525 4526
static int smack_inode_copy_up(struct dentry *dentry, struct cred **new)
{

	struct task_smack *tsp;
	struct smack_known *skp;
	struct inode_smack *isp;
	struct cred *new_creds = *new;

	if (new_creds == NULL) {
		new_creds = prepare_creds();
		if (new_creds == NULL)
			return -ENOMEM;
	}

4527
	tsp = smack_cred(new_creds);
4528 4529 4530 4531

	/*
	 * Get label from overlay inode and set it in create_sid
	 */
4532
	isp = smack_inode(d_inode(dentry->d_parent));
4533 4534 4535 4536 4537 4538 4539 4540 4541 4542 4543 4544 4545 4546 4547 4548 4549 4550 4551 4552 4553 4554
	skp = isp->smk_inode;
	tsp->smk_task = skp;
	*new = new_creds;
	return 0;
}

static int smack_inode_copy_up_xattr(const char *name)
{
	/*
	 * Return 1 if this is the smack access Smack attribute.
	 */
	if (strcmp(name, XATTR_NAME_SMACK) == 0)
		return 1;

	return -EOPNOTSUPP;
}

static int smack_dentry_create_files_as(struct dentry *dentry, int mode,
					struct qstr *name,
					const struct cred *old,
					struct cred *new)
{
4555 4556
	struct task_smack *otsp = smack_cred(old);
	struct task_smack *ntsp = smack_cred(new);
4557 4558 4559 4560 4561 4562 4563 4564 4565 4566 4567 4568
	struct inode_smack *isp;
	int may;

	/*
	 * Use the process credential unless all of
	 * the transmuting criteria are met
	 */
	ntsp->smk_task = otsp->smk_task;

	/*
	 * the attribute of the containing directory
	 */
4569
	isp = smack_inode(d_inode(dentry->d_parent));
4570 4571 4572 4573 4574 4575 4576 4577 4578 4579 4580 4581 4582 4583 4584 4585 4586 4587 4588

	if (isp->smk_flags & SMK_INODE_TRANSMUTE) {
		rcu_read_lock();
		may = smk_access_entry(otsp->smk_task->smk_known,
				       isp->smk_inode->smk_known,
				       &otsp->smk_task->smk_rules);
		rcu_read_unlock();

		/*
		 * If the directory is transmuting and the rule
		 * providing access is transmuting use the containing
		 * directory label instead of the process label.
		 */
		if (may > 0 && (may & MAY_TRANSMUTE))
			ntsp->smk_task = isp->smk_inode;
	}
	return 0;
}

4589 4590
struct lsm_blob_sizes smack_blob_sizes __lsm_ro_after_init = {
	.lbs_cred = sizeof(struct task_smack),
4591
	.lbs_file = sizeof(struct smack_known *),
4592
	.lbs_inode = sizeof(struct inode_smack),
4593 4594
	.lbs_ipc = sizeof(struct smack_known *),
	.lbs_msg_msg = sizeof(struct smack_known *),
4595 4596
};

4597
static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
4598 4599 4600 4601
	LSM_HOOK_INIT(ptrace_access_check, smack_ptrace_access_check),
	LSM_HOOK_INIT(ptrace_traceme, smack_ptrace_traceme),
	LSM_HOOK_INIT(syslog, smack_syslog),

A
Al Viro 已提交
4602
	LSM_HOOK_INIT(fs_context_dup, smack_fs_context_dup),
4603 4604
	LSM_HOOK_INIT(fs_context_parse_param, smack_fs_context_parse_param),

4605 4606
	LSM_HOOK_INIT(sb_alloc_security, smack_sb_alloc_security),
	LSM_HOOK_INIT(sb_free_security, smack_sb_free_security),
4607
	LSM_HOOK_INIT(sb_free_mnt_opts, smack_free_mnt_opts),
4608
	LSM_HOOK_INIT(sb_eat_lsm_opts, smack_sb_eat_lsm_opts),
4609
	LSM_HOOK_INIT(sb_statfs, smack_sb_statfs),
4610
	LSM_HOOK_INIT(sb_set_mnt_opts, smack_set_mnt_opts),
4611 4612 4613 4614 4615 4616 4617 4618 4619 4620 4621 4622 4623 4624 4625 4626 4627 4628 4629 4630 4631 4632 4633 4634 4635 4636 4637 4638 4639 4640 4641 4642 4643 4644 4645 4646 4647

	LSM_HOOK_INIT(bprm_set_creds, smack_bprm_set_creds),

	LSM_HOOK_INIT(inode_alloc_security, smack_inode_alloc_security),
	LSM_HOOK_INIT(inode_init_security, smack_inode_init_security),
	LSM_HOOK_INIT(inode_link, smack_inode_link),
	LSM_HOOK_INIT(inode_unlink, smack_inode_unlink),
	LSM_HOOK_INIT(inode_rmdir, smack_inode_rmdir),
	LSM_HOOK_INIT(inode_rename, smack_inode_rename),
	LSM_HOOK_INIT(inode_permission, smack_inode_permission),
	LSM_HOOK_INIT(inode_setattr, smack_inode_setattr),
	LSM_HOOK_INIT(inode_getattr, smack_inode_getattr),
	LSM_HOOK_INIT(inode_setxattr, smack_inode_setxattr),
	LSM_HOOK_INIT(inode_post_setxattr, smack_inode_post_setxattr),
	LSM_HOOK_INIT(inode_getxattr, smack_inode_getxattr),
	LSM_HOOK_INIT(inode_removexattr, smack_inode_removexattr),
	LSM_HOOK_INIT(inode_getsecurity, smack_inode_getsecurity),
	LSM_HOOK_INIT(inode_setsecurity, smack_inode_setsecurity),
	LSM_HOOK_INIT(inode_listsecurity, smack_inode_listsecurity),
	LSM_HOOK_INIT(inode_getsecid, smack_inode_getsecid),

	LSM_HOOK_INIT(file_alloc_security, smack_file_alloc_security),
	LSM_HOOK_INIT(file_ioctl, smack_file_ioctl),
	LSM_HOOK_INIT(file_lock, smack_file_lock),
	LSM_HOOK_INIT(file_fcntl, smack_file_fcntl),
	LSM_HOOK_INIT(mmap_file, smack_mmap_file),
	LSM_HOOK_INIT(mmap_addr, cap_mmap_addr),
	LSM_HOOK_INIT(file_set_fowner, smack_file_set_fowner),
	LSM_HOOK_INIT(file_send_sigiotask, smack_file_send_sigiotask),
	LSM_HOOK_INIT(file_receive, smack_file_receive),

	LSM_HOOK_INIT(file_open, smack_file_open),

	LSM_HOOK_INIT(cred_alloc_blank, smack_cred_alloc_blank),
	LSM_HOOK_INIT(cred_free, smack_cred_free),
	LSM_HOOK_INIT(cred_prepare, smack_cred_prepare),
	LSM_HOOK_INIT(cred_transfer, smack_cred_transfer),
4648
	LSM_HOOK_INIT(cred_getsecid, smack_cred_getsecid),
4649 4650 4651 4652 4653 4654 4655 4656 4657 4658 4659 4660 4661 4662 4663 4664 4665 4666 4667 4668
	LSM_HOOK_INIT(kernel_act_as, smack_kernel_act_as),
	LSM_HOOK_INIT(kernel_create_files_as, smack_kernel_create_files_as),
	LSM_HOOK_INIT(task_setpgid, smack_task_setpgid),
	LSM_HOOK_INIT(task_getpgid, smack_task_getpgid),
	LSM_HOOK_INIT(task_getsid, smack_task_getsid),
	LSM_HOOK_INIT(task_getsecid, smack_task_getsecid),
	LSM_HOOK_INIT(task_setnice, smack_task_setnice),
	LSM_HOOK_INIT(task_setioprio, smack_task_setioprio),
	LSM_HOOK_INIT(task_getioprio, smack_task_getioprio),
	LSM_HOOK_INIT(task_setscheduler, smack_task_setscheduler),
	LSM_HOOK_INIT(task_getscheduler, smack_task_getscheduler),
	LSM_HOOK_INIT(task_movememory, smack_task_movememory),
	LSM_HOOK_INIT(task_kill, smack_task_kill),
	LSM_HOOK_INIT(task_to_inode, smack_task_to_inode),

	LSM_HOOK_INIT(ipc_permission, smack_ipc_permission),
	LSM_HOOK_INIT(ipc_getsecid, smack_ipc_getsecid),

	LSM_HOOK_INIT(msg_msg_alloc_security, smack_msg_msg_alloc_security),

4669
	LSM_HOOK_INIT(msg_queue_alloc_security, smack_ipc_alloc_security),
4670 4671 4672 4673 4674
	LSM_HOOK_INIT(msg_queue_associate, smack_msg_queue_associate),
	LSM_HOOK_INIT(msg_queue_msgctl, smack_msg_queue_msgctl),
	LSM_HOOK_INIT(msg_queue_msgsnd, smack_msg_queue_msgsnd),
	LSM_HOOK_INIT(msg_queue_msgrcv, smack_msg_queue_msgrcv),

4675
	LSM_HOOK_INIT(shm_alloc_security, smack_ipc_alloc_security),
4676 4677 4678 4679
	LSM_HOOK_INIT(shm_associate, smack_shm_associate),
	LSM_HOOK_INIT(shm_shmctl, smack_shm_shmctl),
	LSM_HOOK_INIT(shm_shmat, smack_shm_shmat),

4680
	LSM_HOOK_INIT(sem_alloc_security, smack_ipc_alloc_security),
4681 4682 4683 4684 4685 4686 4687 4688 4689 4690 4691 4692 4693
	LSM_HOOK_INIT(sem_associate, smack_sem_associate),
	LSM_HOOK_INIT(sem_semctl, smack_sem_semctl),
	LSM_HOOK_INIT(sem_semop, smack_sem_semop),

	LSM_HOOK_INIT(d_instantiate, smack_d_instantiate),

	LSM_HOOK_INIT(getprocattr, smack_getprocattr),
	LSM_HOOK_INIT(setprocattr, smack_setprocattr),

	LSM_HOOK_INIT(unix_stream_connect, smack_unix_stream_connect),
	LSM_HOOK_INIT(unix_may_send, smack_unix_may_send),

	LSM_HOOK_INIT(socket_post_create, smack_socket_post_create),
4694
	LSM_HOOK_INIT(socket_socketpair, smack_socket_socketpair),
C
Casey Schaufler 已提交
4695
#ifdef SMACK_IPV6_PORT_LABELING
4696
	LSM_HOOK_INIT(socket_bind, smack_socket_bind),
C
Casey Schaufler 已提交
4697
#endif
4698 4699 4700 4701 4702 4703 4704 4705 4706 4707
	LSM_HOOK_INIT(socket_connect, smack_socket_connect),
	LSM_HOOK_INIT(socket_sendmsg, smack_socket_sendmsg),
	LSM_HOOK_INIT(socket_sock_rcv_skb, smack_socket_sock_rcv_skb),
	LSM_HOOK_INIT(socket_getpeersec_stream, smack_socket_getpeersec_stream),
	LSM_HOOK_INIT(socket_getpeersec_dgram, smack_socket_getpeersec_dgram),
	LSM_HOOK_INIT(sk_alloc_security, smack_sk_alloc_security),
	LSM_HOOK_INIT(sk_free_security, smack_sk_free_security),
	LSM_HOOK_INIT(sock_graft, smack_sock_graft),
	LSM_HOOK_INIT(inet_conn_request, smack_inet_conn_request),
	LSM_HOOK_INIT(inet_csk_clone, smack_inet_csk_clone),
4708

4709 4710
 /* key management security hooks */
#ifdef CONFIG_KEYS
4711 4712 4713 4714
	LSM_HOOK_INIT(key_alloc, smack_key_alloc),
	LSM_HOOK_INIT(key_free, smack_key_free),
	LSM_HOOK_INIT(key_permission, smack_key_permission),
	LSM_HOOK_INIT(key_getsecurity, smack_key_getsecurity),
4715
#endif /* CONFIG_KEYS */
4716 4717 4718

 /* Audit hooks */
#ifdef CONFIG_AUDIT
4719 4720 4721
	LSM_HOOK_INIT(audit_rule_init, smack_audit_rule_init),
	LSM_HOOK_INIT(audit_rule_known, smack_audit_rule_known),
	LSM_HOOK_INIT(audit_rule_match, smack_audit_rule_match),
4722 4723
#endif /* CONFIG_AUDIT */

4724 4725 4726 4727 4728 4729
	LSM_HOOK_INIT(ismaclabel, smack_ismaclabel),
	LSM_HOOK_INIT(secid_to_secctx, smack_secid_to_secctx),
	LSM_HOOK_INIT(secctx_to_secid, smack_secctx_to_secid),
	LSM_HOOK_INIT(inode_notifysecctx, smack_inode_notifysecctx),
	LSM_HOOK_INIT(inode_setsecctx, smack_inode_setsecctx),
	LSM_HOOK_INIT(inode_getsecctx, smack_inode_getsecctx),
4730 4731 4732
	LSM_HOOK_INIT(inode_copy_up, smack_inode_copy_up),
	LSM_HOOK_INIT(inode_copy_up_xattr, smack_inode_copy_up_xattr),
	LSM_HOOK_INIT(dentry_create_files_as, smack_dentry_create_files_as),
4733 4734
};

4735

4736
static __init void init_smack_known_list(void)
4737
{
4738 4739 4740 4741 4742 4743 4744 4745 4746 4747 4748 4749 4750 4751 4752 4753 4754 4755 4756
	/*
	 * Initialize rule list locks
	 */
	mutex_init(&smack_known_huh.smk_rules_lock);
	mutex_init(&smack_known_hat.smk_rules_lock);
	mutex_init(&smack_known_floor.smk_rules_lock);
	mutex_init(&smack_known_star.smk_rules_lock);
	mutex_init(&smack_known_web.smk_rules_lock);
	/*
	 * Initialize rule lists
	 */
	INIT_LIST_HEAD(&smack_known_huh.smk_rules);
	INIT_LIST_HEAD(&smack_known_hat.smk_rules);
	INIT_LIST_HEAD(&smack_known_star.smk_rules);
	INIT_LIST_HEAD(&smack_known_floor.smk_rules);
	INIT_LIST_HEAD(&smack_known_web.smk_rules);
	/*
	 * Create the known labels list
	 */
4757 4758 4759 4760 4761
	smk_insert_entry(&smack_known_huh);
	smk_insert_entry(&smack_known_hat);
	smk_insert_entry(&smack_known_star);
	smk_insert_entry(&smack_known_floor);
	smk_insert_entry(&smack_known_web);
4762 4763
}

4764 4765 4766 4767 4768 4769 4770
/**
 * smack_init - initialize the smack system
 *
 * Returns 0
 */
static __init int smack_init(void)
{
4771
	struct cred *cred = (struct cred *) current->cred;
4772
	struct task_smack *tsp;
D
David Howells 已提交
4773

4774 4775 4776 4777
	smack_inode_cache = KMEM_CACHE(inode_smack, 0);
	if (!smack_inode_cache)
		return -ENOMEM;

4778 4779 4780 4781 4782 4783
	smack_rule_cache = KMEM_CACHE(smack_rule, 0);
	if (!smack_rule_cache) {
		kmem_cache_destroy(smack_inode_cache);
		return -ENOMEM;
	}

4784 4785 4786 4787 4788 4789 4790 4791 4792 4793
	/*
	 * Set the security state for the initial task.
	 */
	tsp = smack_cred(cred);
	init_task_smack(tsp, &smack_known_floor, &smack_known_floor);

	/*
	 * Register with LSM
	 */
	security_add_hooks(smack_hooks, ARRAY_SIZE(smack_hooks), "smack");
4794 4795
	smack_enabled = 1;

C
Casey Schaufler 已提交
4796 4797 4798 4799 4800 4801 4802 4803 4804 4805
	pr_info("Smack:  Initializing.\n");
#ifdef CONFIG_SECURITY_SMACK_NETFILTER
	pr_info("Smack:  Netfilter enabled.\n");
#endif
#ifdef SMACK_IPV6_PORT_LABELING
	pr_info("Smack:  IPv6 port labeling enabled.\n");
#endif
#ifdef SMACK_IPV6_SECMARK_LABELING
	pr_info("Smack:  IPv6 Netfilter enabled.\n");
#endif
4806

4807 4808
	/* initialize the smack_known_list */
	init_smack_known_list();
4809 4810 4811 4812 4813 4814 4815 4816

	return 0;
}

/*
 * Smack requires early initialization in order to label
 * all processes and objects when they are created.
 */
4817
DEFINE_LSM(smack) = {
4818
	.name = "smack",
4819
	.flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE,
4820
	.blobs = &smack_blob_sizes,
4821 4822
	.init = smack_init,
};