smack_lsm.c 104.0 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/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 "smack.h"

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#define task_security(task)	(task_cred_xxx((task), security))

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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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#if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
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LIST_HEAD(smk_ipv6_port_list);
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#endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */
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static struct kmem_cache *smack_inode_cache;
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int smack_enabled;
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#ifdef CONFIG_SECURITY_SMACK_BRINGUP
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;

	smk_bu_mode(mode, acc);
	pr_info("Smack Bringup: (%s %s %s) %s\n",
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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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{
	struct task_smack *tsp = current_security();
	char acc[SMK_NUM_ACCESS_TYPE + 1];

	if (rc <= 0)
		return rc;

	smk_bu_mode(mode, acc);
	pr_info("Smack Bringup: (%s %s %s) %s %s\n",
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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)
{
	struct task_smack *tsp = current_security();
	struct task_smack *otsp = task_security(otp);
	char acc[SMK_NUM_ACCESS_TYPE + 1];

	if (rc <= 0)
		return rc;

	smk_bu_mode(mode, acc);
	pr_info("Smack Bringup: (%s %s %s) %s to %s\n",
		tsp->smk_task->smk_known, otsp->smk_task->smk_known, acc,
		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)
{
	struct task_smack *tsp = current_security();
	char acc[SMK_NUM_ACCESS_TYPE + 1];

	if (rc <= 0)
		return rc;

	smk_bu_mode(mode, acc);
	pr_info("Smack Bringup: (%s %s %s) inode=(%s %ld) %s\n",
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		tsp->smk_task->smk_known, smk_of_inode(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)
{
	struct task_smack *tsp = current_security();
	struct smack_known *sskp = tsp->smk_task;
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	struct inode *inode = file_inode(file);
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	char acc[SMK_NUM_ACCESS_TYPE + 1];

	if (rc <= 0)
		return rc;

	smk_bu_mode(mode, acc);
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	pr_info("Smack Bringup: (%s %s %s) file=(%s %ld %pD) %s\n",
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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)
{
	struct task_smack *tsp = cred->security;
	struct smack_known *sskp = tsp->smk_task;
	struct inode *inode = file->f_inode;
	char acc[SMK_NUM_ACCESS_TYPE + 1];

	if (rc <= 0)
		return rc;

	smk_bu_mode(mode, acc);
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	pr_info("Smack Bringup: (%s %s %s) file=(%s %ld %pD) %s\n",
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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
 *
 * Returns a pointer to the master list entry for the Smack label
 * or NULL if there was no label to fetch.
 */
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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_op->getxattr == NULL)
		return NULL;

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	buffer = kzalloc(SMK_LONGLABEL, GFP_KERNEL);
	if (buffer == NULL)
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		return NULL;

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	rc = ip->i_op->getxattr(dp, name, buffer, SMK_LONGLABEL);
	if (rc > 0)
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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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}

/**
 * new_inode_smack - allocate an inode security blob
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 * @skp: a pointer to the Smack label entry to use in the blob
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 *
 * Returns the new blob or NULL if there's no memory available
 */
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struct inode_smack *new_inode_smack(struct smack_known *skp)
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{
	struct inode_smack *isp;

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	isp = kmem_cache_zalloc(smack_inode_cache, GFP_NOFS);
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	if (isp == NULL)
		return NULL;

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	isp->smk_inode = skp;
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	isp->smk_flags = 0;
	mutex_init(&isp->smk_lock);

	return isp;
}

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/**
 * new_task_smack - allocate a task security blob
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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
 * @gfp: type of the memory for the allocation
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 *
 * Returns the new blob or NULL if there's no memory available
 */
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static struct task_smack *new_task_smack(struct smack_known *task,
					struct smack_known *forked, gfp_t gfp)
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{
	struct task_smack *tsp;

	tsp = kzalloc(sizeof(struct task_smack), gfp);
	if (tsp == NULL)
		return NULL;

	tsp->smk_task = task;
	tsp->smk_forked = forked;
	INIT_LIST_HEAD(&tsp->smk_rules);
	mutex_init(&tsp->smk_rules_lock);

	return tsp;
}

/**
 * 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;

	INIT_LIST_HEAD(nhead);

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

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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)
{
	switch (mode) {
	case PTRACE_MODE_READ:
		return MAY_READ;
	case PTRACE_MODE_ATTACH:
		return MAY_READWRITE;
	}

	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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	if ((mode & PTRACE_MODE_NOAUDIT) == 0) {
		smk_ad_init(&ad, func, LSM_AUDIT_DATA_TASK);
		smk_ad_setfield_u_tsk(&ad, tracer);
		saip = &ad;
	}

	tsp = task_security(tracer);
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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;
		else if (capable(CAP_SYS_PTRACE))
			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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		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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	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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{
	int rc;
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	struct smack_known *skp;
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	rc = cap_ptrace_access_check(ctp, mode);
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	if (rc != 0)
		return rc;

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	skp = smk_of_task(task_security(ctp));
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	rc = smk_ptrace_rule_check(current, skp, mode, __func__);
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	return rc;
}

/**
 * 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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	rc = cap_ptrace_traceme(ptp);
	if (rc != 0)
		return rc;
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	skp = smk_of_task(current_security());
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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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	/*
	 * smk_initialized will be zero from kzalloc.
	 */
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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;
}

/**
 * smack_sb_copy_data - copy mount options data for processing
 * @orig: where to start
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 * @smackopts: mount options string
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 *
 * Returns 0 on success or -ENOMEM on error.
 *
 * Copy the Smack specific mount options out of the mount
 * options list.
 */
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static int smack_sb_copy_data(char *orig, char *smackopts)
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{
	char *cp, *commap, *otheropts, *dp;

	otheropts = (char *)get_zeroed_page(GFP_KERNEL);
	if (otheropts == NULL)
		return -ENOMEM;

	for (cp = orig, commap = orig; commap != NULL; cp = commap + 1) {
		if (strstr(cp, SMK_FSDEFAULT) == cp)
			dp = smackopts;
		else if (strstr(cp, SMK_FSFLOOR) == cp)
			dp = smackopts;
		else if (strstr(cp, SMK_FSHAT) == cp)
			dp = smackopts;
		else if (strstr(cp, SMK_FSROOT) == cp)
			dp = smackopts;
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		else if (strstr(cp, SMK_FSTRANS) == cp)
			dp = smackopts;
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		else
			dp = otheropts;

		commap = strchr(cp, ',');
		if (commap != NULL)
			*commap = '\0';

		if (*dp != '\0')
			strcat(dp, ",");
		strcat(dp, cp);
	}

	strcpy(orig, otheropts);
	free_page((unsigned long)otheropts);

	return 0;
}

/**
 * smack_sb_kern_mount - Smack specific mount processing
 * @sb: the file system superblock
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 * @flags: the mount flags
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 * @data: the smack mount options
 *
 * Returns 0 on success, an error code on failure
 */
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static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data)
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{
	struct dentry *root = sb->s_root;
	struct inode *inode = root->d_inode;
	struct superblock_smack *sp = sb->s_security;
	struct inode_smack *isp;
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	struct smack_known *skp;
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	char *op;
	char *commap;
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	int transmute = 0;
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	int specified = 0;
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	if (sp->smk_initialized)
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		return 0;
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	sp->smk_initialized = 1;

	for (op = data; op != NULL; op = commap) {
		commap = strchr(op, ',');
		if (commap != NULL)
			*commap++ = '\0';

		if (strncmp(op, SMK_FSHAT, strlen(SMK_FSHAT)) == 0) {
			op += strlen(SMK_FSHAT);
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			skp = smk_import_entry(op, 0);
			if (skp != NULL) {
				sp->smk_hat = skp;
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				specified = 1;
			}
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		} else if (strncmp(op, SMK_FSFLOOR, strlen(SMK_FSFLOOR)) == 0) {
			op += strlen(SMK_FSFLOOR);
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			skp = smk_import_entry(op, 0);
			if (skp != NULL) {
				sp->smk_floor = skp;
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				specified = 1;
			}
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		} else if (strncmp(op, SMK_FSDEFAULT,
				   strlen(SMK_FSDEFAULT)) == 0) {
			op += strlen(SMK_FSDEFAULT);
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			skp = smk_import_entry(op, 0);
			if (skp != NULL) {
				sp->smk_default = skp;
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				specified = 1;
			}
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		} else if (strncmp(op, SMK_FSROOT, strlen(SMK_FSROOT)) == 0) {
			op += strlen(SMK_FSROOT);
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			skp = smk_import_entry(op, 0);
			if (skp != NULL) {
				sp->smk_root = skp;
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				specified = 1;
			}
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		} else if (strncmp(op, SMK_FSTRANS, strlen(SMK_FSTRANS)) == 0) {
			op += strlen(SMK_FSTRANS);
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			skp = smk_import_entry(op, 0);
			if (skp != NULL) {
				sp->smk_root = skp;
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				transmute = 1;
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				specified = 1;
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			}
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		}
	}

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	if (!smack_privileged(CAP_MAC_ADMIN)) {
		/*
		 * Unprivileged mounts don't get to specify Smack values.
		 */
		if (specified)
			return -EPERM;
		/*
		 * Unprivileged mounts get root and default from the caller.
		 */
		skp = smk_of_current();
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		sp->smk_root = skp;
		sp->smk_default = skp;
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	}
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	/*
	 * Initialize the root inode.
	 */
	isp = inode->i_security;
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	if (isp == NULL) {
		isp = new_inode_smack(sp->smk_root);
		if (isp == NULL)
			return -ENOMEM;
		inode->i_security = isp;
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	} else
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		isp->smk_inode = sp->smk_root;

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	if (transmute)
		isp->smk_flags |= SMK_INODE_TRANSMUTE;

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	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
656 657 658
	int rc;
	struct smk_audit_info ad;

659
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
E
Etienne Basset 已提交
660
	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
661

E
Etienne Basset 已提交
662
	rc = smk_curacc(sbp->smk_floor, MAY_READ, &ad);
C
Casey Schaufler 已提交
663
	rc = smk_bu_current("statfs", sbp->smk_floor, MAY_READ, rc);
E
Etienne Basset 已提交
664
	return rc;
665 666
}

667 668 669 670
/*
 * BPRM hooks
 */

C
Casey Schaufler 已提交
671 672 673 674
/**
 * smack_bprm_set_creds - set creds for exec
 * @bprm: the exec information
 *
675
 * Returns 0 if it gets a blob, -EPERM if exec forbidden and -ENOMEM otherwise
C
Casey Schaufler 已提交
676
 */
677 678
static int smack_bprm_set_creds(struct linux_binprm *bprm)
{
A
Al Viro 已提交
679
	struct inode *inode = file_inode(bprm->file);
680
	struct task_smack *bsp = bprm->cred->security;
681 682 683 684 685 686 687 688 689 690
	struct inode_smack *isp;
	int rc;

	rc = cap_bprm_set_creds(bprm);
	if (rc != 0)
		return rc;

	if (bprm->cred_prepared)
		return 0;

691 692
	isp = inode->i_security;
	if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task)
693 694
		return 0;

695 696 697 698 699 700 701 702
	if (bprm->unsafe & (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
		struct task_struct *tracer;
		rc = 0;

		rcu_read_lock();
		tracer = ptrace_parent(current);
		if (likely(tracer != NULL))
			rc = smk_ptrace_rule_check(tracer,
703
						   isp->smk_task,
704 705 706 707 708 709 710
						   PTRACE_MODE_ATTACH,
						   __func__);
		rcu_read_unlock();

		if (rc != 0)
			return rc;
	} else if (bprm->unsafe)
711
		return -EPERM;
712

713 714
	bsp->smk_task = isp->smk_task;
	bprm->per_clear |= PER_CLEAR_ON_SETID;
715

716 717
	return 0;
}
718

719 720 721 722 723 724 725 726 727
/**
 * smack_bprm_committing_creds - Prepare to install the new credentials
 * from bprm.
 *
 * @bprm: binprm for exec
 */
static void smack_bprm_committing_creds(struct linux_binprm *bprm)
{
	struct task_smack *bsp = bprm->cred->security;
728

729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747
	if (bsp->smk_task != bsp->smk_forked)
		current->pdeath_signal = 0;
}

/**
 * smack_bprm_secureexec - Return the decision to use secureexec.
 * @bprm: binprm for exec
 *
 * Returns 0 on success.
 */
static int smack_bprm_secureexec(struct linux_binprm *bprm)
{
	struct task_smack *tsp = current_security();
	int ret = cap_bprm_secureexec(bprm);

	if (!ret && (tsp->smk_task != tsp->smk_forked))
		ret = 1;

	return ret;
748 749
}

750 751 752 753 754 755
/*
 * Inode hooks
 */

/**
 * smack_inode_alloc_security - allocate an inode blob
756
 * @inode: the inode in need of a blob
757 758 759 760 761
 *
 * Returns 0 if it gets a blob, -ENOMEM otherwise
 */
static int smack_inode_alloc_security(struct inode *inode)
{
762 763
	struct smack_known *skp = smk_of_current();

764
	inode->i_security = new_inode_smack(skp);
765 766 767 768 769 770 771
	if (inode->i_security == NULL)
		return -ENOMEM;
	return 0;
}

/**
 * smack_inode_free_security - free an inode blob
772
 * @inode: the inode with a blob
773 774 775 776 777
 *
 * Clears the blob pointer in inode
 */
static void smack_inode_free_security(struct inode *inode)
{
778
	kmem_cache_free(smack_inode_cache, inode->i_security);
779 780 781 782 783
	inode->i_security = NULL;
}

/**
 * smack_inode_init_security - copy out the smack from an inode
784 785
 * @inode: the newly created inode
 * @dir: containing directory object
786
 * @qstr: unused
787 788 789 790 791 792 793
 * @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,
794
				     const struct qstr *qstr, const char **name,
795
				     void **value, size_t *len)
796
{
C
Casey Schaufler 已提交
797
	struct inode_smack *issp = inode->i_security;
798
	struct smack_known *skp = smk_of_current();
799 800
	struct smack_known *isp = smk_of_inode(inode);
	struct smack_known *dsp = smk_of_inode(dir);
801
	int may;
802

803 804
	if (name)
		*name = XATTR_SMACK_SUFFIX;
805

806
	if (value && len) {
807
		rcu_read_lock();
808 809
		may = smk_access_entry(skp->smk_known, dsp->smk_known,
				       &skp->smk_rules);
810
		rcu_read_unlock();
811 812 813 814 815

		/*
		 * If the access rule allows transmutation and
		 * the directory requests transmutation then
		 * by all means transmute.
C
Casey Schaufler 已提交
816
		 * Mark the inode as changed.
817
		 */
818
		if (may > 0 && ((may & MAY_TRANSMUTE) != 0) &&
C
Casey Schaufler 已提交
819
		    smk_inode_transmutable(dir)) {
820
			isp = dsp;
C
Casey Schaufler 已提交
821 822
			issp->smk_flags |= SMK_INODE_CHANGED;
		}
823

824
		*value = kstrdup(isp->smk_known, GFP_NOFS);
825 826 827
		if (*value == NULL)
			return -ENOMEM;

828
		*len = strlen(isp->smk_known);
829
	}
830 831 832 833 834 835 836 837 838 839 840 841 842 843 844

	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)
{
845
	struct smack_known *isp;
E
Etienne Basset 已提交
846 847 848
	struct smk_audit_info ad;
	int rc;

849
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
E
Etienne Basset 已提交
850
	smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
851 852

	isp = smk_of_inode(old_dentry->d_inode);
E
Etienne Basset 已提交
853
	rc = smk_curacc(isp, MAY_WRITE, &ad);
C
Casey Schaufler 已提交
854
	rc = smk_bu_inode(old_dentry->d_inode, MAY_WRITE, rc);
855 856 857

	if (rc == 0 && new_dentry->d_inode != NULL) {
		isp = smk_of_inode(new_dentry->d_inode);
E
Etienne Basset 已提交
858 859
		smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
		rc = smk_curacc(isp, MAY_WRITE, &ad);
C
Casey Schaufler 已提交
860
		rc = smk_bu_inode(new_dentry->d_inode, MAY_WRITE, rc);
861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876
	}

	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)
{
	struct inode *ip = dentry->d_inode;
E
Etienne Basset 已提交
877
	struct smk_audit_info ad;
878 879
	int rc;

880
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
E
Etienne Basset 已提交
881 882
	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);

883 884 885
	/*
	 * You need write access to the thing you're unlinking
	 */
E
Etienne Basset 已提交
886
	rc = smk_curacc(smk_of_inode(ip), MAY_WRITE, &ad);
C
Casey Schaufler 已提交
887
	rc = smk_bu_inode(ip, MAY_WRITE, rc);
E
Etienne Basset 已提交
888
	if (rc == 0) {
889 890 891
		/*
		 * You also need write access to the containing directory
		 */
892
		smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
E
Etienne Basset 已提交
893 894
		smk_ad_setfield_u_fs_inode(&ad, dir);
		rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
C
Casey Schaufler 已提交
895
		rc = smk_bu_inode(dir, MAY_WRITE, rc);
E
Etienne Basset 已提交
896
	}
897 898 899 900 901 902 903 904 905 906 907 908 909
	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
910
	struct smk_audit_info ad;
911 912
	int rc;

913
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
E
Etienne Basset 已提交
914 915
	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);

916 917 918
	/*
	 * You need write access to the thing you're removing
	 */
E
Etienne Basset 已提交
919
	rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
C
Casey Schaufler 已提交
920
	rc = smk_bu_inode(dentry->d_inode, MAY_WRITE, rc);
E
Etienne Basset 已提交
921
	if (rc == 0) {
922 923 924
		/*
		 * You also need write access to the containing directory
		 */
925
		smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
E
Etienne Basset 已提交
926 927
		smk_ad_setfield_u_fs_inode(&ad, dir);
		rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
C
Casey Schaufler 已提交
928
		rc = smk_bu_inode(dir, MAY_WRITE, rc);
E
Etienne Basset 已提交
929
	}
930 931 932 933 934 935

	return rc;
}

/**
 * smack_inode_rename - Smack check on rename
936 937 938 939
 * @old_inode: unused
 * @old_dentry: the old object
 * @new_inode: unused
 * @new_dentry: the new object
940 941 942 943 944 945 946 947 948 949 950 951
 *
 * 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;
952
	struct smack_known *isp;
E
Etienne Basset 已提交
953 954
	struct smk_audit_info ad;

955
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
E
Etienne Basset 已提交
956
	smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
957 958

	isp = smk_of_inode(old_dentry->d_inode);
E
Etienne Basset 已提交
959
	rc = smk_curacc(isp, MAY_READWRITE, &ad);
C
Casey Schaufler 已提交
960
	rc = smk_bu_inode(old_dentry->d_inode, MAY_READWRITE, rc);
961 962 963

	if (rc == 0 && new_dentry->d_inode != NULL) {
		isp = smk_of_inode(new_dentry->d_inode);
E
Etienne Basset 已提交
964 965
		smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
		rc = smk_curacc(isp, MAY_READWRITE, &ad);
C
Casey Schaufler 已提交
966
		rc = smk_bu_inode(new_dentry->d_inode, MAY_READWRITE, rc);
967 968 969 970 971 972 973 974 975 976 977 978 979
	}
	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
 */
980
static int smack_inode_permission(struct inode *inode, int mask)
981
{
E
Etienne Basset 已提交
982
	struct smk_audit_info ad;
983
	int no_block = mask & MAY_NOT_BLOCK;
C
Casey Schaufler 已提交
984
	int rc;
985 986

	mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
987 988 989 990 991
	/*
	 * No permission to check. Existence test. Yup, it's there.
	 */
	if (mask == 0)
		return 0;
992 993

	/* May be droppable after audit */
994
	if (no_block)
995
		return -ECHILD;
996
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
E
Etienne Basset 已提交
997
	smk_ad_setfield_u_fs_inode(&ad, inode);
C
Casey Schaufler 已提交
998 999 1000
	rc = smk_curacc(smk_of_inode(inode), mask, &ad);
	rc = smk_bu_inode(inode, mask, rc);
	return rc;
1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011
}

/**
 * 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
1012
	struct smk_audit_info ad;
C
Casey Schaufler 已提交
1013 1014
	int rc;

1015 1016 1017 1018 1019
	/*
	 * Need to allow for clearing the setuid bit.
	 */
	if (iattr->ia_valid & ATTR_FORCE)
		return 0;
1020
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
E
Etienne Basset 已提交
1021
	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1022

C
Casey Schaufler 已提交
1023 1024 1025
	rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
	rc = smk_bu_inode(dentry->d_inode, MAY_WRITE, rc);
	return rc;
1026 1027 1028 1029
}

/**
 * smack_inode_getattr - Smack check for getting attributes
1030
 * @mnt: vfsmount of the object
1031 1032 1033 1034 1035 1036
 * @dentry: the object
 *
 * Returns 0 if access is permitted, an error code otherwise
 */
static int smack_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
{
E
Etienne Basset 已提交
1037
	struct smk_audit_info ad;
1038
	struct path path;
C
Casey Schaufler 已提交
1039
	int rc;
E
Etienne Basset 已提交
1040

1041 1042
	path.dentry = dentry;
	path.mnt = mnt;
E
Etienne Basset 已提交
1043

1044
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1045
	smk_ad_setfield_u_fs_path(&ad, path);
C
Casey Schaufler 已提交
1046 1047 1048
	rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad);
	rc = smk_bu_inode(dentry->d_inode, MAY_READ, rc);
	return rc;
1049 1050 1051 1052 1053 1054
}

/**
 * smack_inode_setxattr - Smack check for setting xattrs
 * @dentry: the object
 * @name: name of the attribute
1055 1056
 * @value: value of the attribute
 * @size: size of the value
1057 1058 1059 1060 1061 1062
 * @flags: unused
 *
 * This protects the Smack attribute explicitly.
 *
 * Returns 0 if access is permitted, an error code otherwise
 */
1063 1064
static int smack_inode_setxattr(struct dentry *dentry, const char *name,
				const void *value, size_t size, int flags)
1065
{
E
Etienne Basset 已提交
1066
	struct smk_audit_info ad;
1067 1068 1069 1070
	struct smack_known *skp;
	int check_priv = 0;
	int check_import = 0;
	int check_star = 0;
1071
	int rc = 0;
1072

1073 1074 1075
	/*
	 * Check label validity here so import won't fail in post_setxattr
	 */
1076 1077
	if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
	    strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
1078 1079 1080 1081 1082 1083 1084 1085
	    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;
1086
	} else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
1087
		check_priv = 1;
1088 1089 1090
		if (size != TRANS_TRUE_SIZE ||
		    strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0)
			rc = -EINVAL;
1091 1092 1093
	} else
		rc = cap_inode_setxattr(dentry, name, value, size, flags);

1094 1095 1096 1097
	if (check_priv && !smack_privileged(CAP_MAC_ADMIN))
		rc = -EPERM;

	if (rc == 0 && check_import) {
1098
		skp = size ? smk_import_entry(value, size) : NULL;
1099 1100 1101 1102 1103
		if (skp == NULL || (check_star &&
		    (skp == &smack_known_star || skp == &smack_known_web)))
			rc = -EINVAL;
	}

1104
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
E
Etienne Basset 已提交
1105 1106
	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);

C
Casey Schaufler 已提交
1107
	if (rc == 0) {
E
Etienne Basset 已提交
1108
		rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
C
Casey Schaufler 已提交
1109 1110
		rc = smk_bu_inode(dentry->d_inode, MAY_WRITE, rc);
	}
1111 1112

	return rc;
1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125
}

/**
 * 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.
 */
1126 1127
static void smack_inode_post_setxattr(struct dentry *dentry, const char *name,
				      const void *value, size_t size, int flags)
1128
{
1129
	struct smack_known *skp;
1130
	struct inode_smack *isp = dentry->d_inode->i_security;
1131

1132 1133 1134 1135 1136
	if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
		isp->smk_flags |= SMK_INODE_TRANSMUTE;
		return;
	}

1137
	if (strcmp(name, XATTR_NAME_SMACK) == 0) {
1138
		skp = smk_import_entry(value, size);
1139
		if (skp != NULL)
1140
			isp->smk_inode = skp;
1141
		else
1142
			isp->smk_inode = &smack_known_invalid;
1143
	} else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) {
1144
		skp = smk_import_entry(value, size);
1145 1146
		if (skp != NULL)
			isp->smk_task = skp;
1147
		else
1148
			isp->smk_task = &smack_known_invalid;
1149
	} else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
1150
		skp = smk_import_entry(value, size);
1151 1152
		if (skp != NULL)
			isp->smk_mmap = skp;
1153
		else
1154 1155
			isp->smk_mmap = &smack_known_invalid;
	}
1156 1157 1158 1159

	return;
}

C
Casey Schaufler 已提交
1160
/**
1161 1162 1163 1164 1165 1166
 * smack_inode_getxattr - Smack check on getxattr
 * @dentry: the object
 * @name: unused
 *
 * Returns 0 if access is permitted, an error code otherwise
 */
1167
static int smack_inode_getxattr(struct dentry *dentry, const char *name)
1168
{
E
Etienne Basset 已提交
1169
	struct smk_audit_info ad;
C
Casey Schaufler 已提交
1170
	int rc;
E
Etienne Basset 已提交
1171

1172
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
E
Etienne Basset 已提交
1173 1174
	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);

C
Casey Schaufler 已提交
1175 1176 1177
	rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad);
	rc = smk_bu_inode(dentry->d_inode, MAY_READ, rc);
	return rc;
1178 1179
}

C
Casey Schaufler 已提交
1180
/**
1181 1182 1183 1184 1185 1186 1187 1188
 * 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
 */
1189
static int smack_inode_removexattr(struct dentry *dentry, const char *name)
1190
{
1191
	struct inode_smack *isp;
E
Etienne Basset 已提交
1192
	struct smk_audit_info ad;
1193
	int rc = 0;
1194

1195 1196
	if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
	    strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
1197
	    strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 ||
1198
	    strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
1199
	    strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0 ||
P
Pankaj Kumar 已提交
1200
	    strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
1201
		if (!smack_privileged(CAP_MAC_ADMIN))
1202 1203 1204 1205
			rc = -EPERM;
	} else
		rc = cap_inode_removexattr(dentry, name);

1206 1207 1208
	if (rc != 0)
		return rc;

1209
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
E
Etienne Basset 已提交
1210
	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1211

1212
	rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
C
Casey Schaufler 已提交
1213
	rc = smk_bu_inode(dentry->d_inode, MAY_WRITE, rc);
1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224
	if (rc != 0)
		return rc;

	isp = dentry->d_inode->i_security;
	/*
	 * Don't do anything special for these.
	 *	XATTR_NAME_SMACKIPIN
	 *	XATTR_NAME_SMACKIPOUT
	 *	XATTR_NAME_SMACKEXEC
	 */
	if (strcmp(name, XATTR_NAME_SMACK) == 0)
1225
		isp->smk_task = NULL;
1226
	else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0)
1227
		isp->smk_mmap = NULL;
1228 1229
	else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0)
		isp->smk_flags &= ~SMK_INODE_TRANSMUTE;
1230

1231
	return 0;
1232 1233 1234 1235 1236 1237 1238
}

/**
 * smack_inode_getsecurity - get smack xattrs
 * @inode: the object
 * @name: attribute name
 * @buffer: where to put the result
1239
 * @alloc: unused
1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250
 *
 * Returns the size of the attribute or an error code
 */
static int smack_inode_getsecurity(const struct inode *inode,
				   const char *name, void **buffer,
				   bool alloc)
{
	struct socket_smack *ssp;
	struct socket *sock;
	struct super_block *sbp;
	struct inode *ip = (struct inode *)inode;
1251
	struct smack_known *isp;
1252 1253 1254 1255 1256
	int ilen;
	int rc = 0;

	if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
		isp = smk_of_inode(inode);
1257 1258
		ilen = strlen(isp->smk_known);
		*buffer = isp->smk_known;
1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269
		return ilen;
	}

	/*
	 * The rest of the Smack xattrs are only on sockets.
	 */
	sbp = ip->i_sb;
	if (sbp->s_magic != SOCKFS_MAGIC)
		return -EOPNOTSUPP;

	sock = SOCKET_I(ip);
1270
	if (sock == NULL || sock->sk == NULL)
1271 1272 1273 1274 1275
		return -EOPNOTSUPP;

	ssp = sock->sk->sk_security;

	if (strcmp(name, XATTR_SMACK_IPIN) == 0)
1276
		isp = ssp->smk_in;
1277
	else if (strcmp(name, XATTR_SMACK_IPOUT) == 0)
1278
		isp = ssp->smk_out;
1279 1280 1281
	else
		return -EOPNOTSUPP;

1282
	ilen = strlen(isp->smk_known);
1283
	if (rc == 0) {
1284
		*buffer = isp->smk_known;
1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302
		rc = ilen;
	}

	return rc;
}


/**
 * smack_inode_listsecurity - list the Smack attributes
 * @inode: the object
 * @buffer: where they go
 * @buffer_size: size of buffer
 *
 * Returns 0 on success, -EINVAL otherwise
 */
static int smack_inode_listsecurity(struct inode *inode, char *buffer,
				    size_t buffer_size)
{
1303
	int len = sizeof(XATTR_NAME_SMACK);
1304

1305
	if (buffer != NULL && len <= buffer_size)
1306
		memcpy(buffer, XATTR_NAME_SMACK, len);
1307 1308

	return len;
1309 1310
}

1311 1312 1313 1314 1315 1316 1317 1318 1319
/**
 * smack_inode_getsecid - Extract inode's security id
 * @inode: inode to extract the info from
 * @secid: where result will be saved
 */
static void smack_inode_getsecid(const struct inode *inode, u32 *secid)
{
	struct inode_smack *isp = inode->i_security;

1320
	*secid = isp->smk_inode->smk_secid;
1321 1322
}

1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352
/*
 * File Hooks
 */

/**
 * smack_file_permission - Smack check on file operations
 * @file: unused
 * @mask: unused
 *
 * Returns 0
 *
 * 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.
 */
static int smack_file_permission(struct file *file, int mask)
{
	return 0;
}

/**
 * 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
1353 1354 1355
 * f_security is the owner security information. It
 * isn't used on file access checks, it's for send_sigio.
 *
1356 1357 1358 1359
 * Returns 0
 */
static int smack_file_alloc_security(struct file *file)
{
1360 1361
	struct smack_known *skp = smk_of_current();

1362
	file->f_security = skp;
1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391
	return 0;
}

/**
 * smack_file_free_security - clear a file security blob
 * @file: the object
 *
 * The security blob for a file is a pointer to the master
 * label list, so no memory is freed.
 */
static void smack_file_free_security(struct file *file)
{
	file->f_security = NULL;
}

/**
 * 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
1392
	struct smk_audit_info ad;
C
Casey Schaufler 已提交
1393
	struct inode *inode = file_inode(file);
E
Etienne Basset 已提交
1394

1395
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
E
Etienne Basset 已提交
1396
	smk_ad_setfield_u_fs_path(&ad, file->f_path);
1397

C
Casey Schaufler 已提交
1398
	if (_IOC_DIR(cmd) & _IOC_WRITE) {
C
Casey Schaufler 已提交
1399
		rc = smk_curacc(smk_of_inode(inode), MAY_WRITE, &ad);
C
Casey Schaufler 已提交
1400 1401
		rc = smk_bu_file(file, MAY_WRITE, rc);
	}
1402

C
Casey Schaufler 已提交
1403
	if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ)) {
C
Casey Schaufler 已提交
1404
		rc = smk_curacc(smk_of_inode(inode), MAY_READ, &ad);
C
Casey Schaufler 已提交
1405 1406
		rc = smk_bu_file(file, MAY_READ, rc);
	}
1407 1408 1409 1410 1411 1412 1413

	return rc;
}

/**
 * smack_file_lock - Smack check on file locking
 * @file: the object
1414
 * @cmd: unused
1415
 *
1416
 * Returns 0 if current has lock access, error code otherwise
1417 1418 1419
 */
static int smack_file_lock(struct file *file, unsigned int cmd)
{
E
Etienne Basset 已提交
1420
	struct smk_audit_info ad;
C
Casey Schaufler 已提交
1421
	int rc;
C
Casey Schaufler 已提交
1422
	struct inode *inode = file_inode(file);
E
Etienne Basset 已提交
1423

1424 1425
	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
1426
	rc = smk_curacc(smk_of_inode(inode), MAY_LOCK, &ad);
C
Casey Schaufler 已提交
1427 1428
	rc = smk_bu_file(file, MAY_LOCK, rc);
	return rc;
1429 1430 1431 1432 1433 1434 1435 1436
}

/**
 * smack_file_fcntl - Smack check on fcntl
 * @file: the object
 * @cmd: what action to check
 * @arg: unused
 *
1437 1438 1439 1440
 * Generally these operations are harmless.
 * File locking operations present an obvious mechanism
 * for passing information, so they require write access.
 *
1441 1442 1443 1444 1445
 * 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
1446
	struct smk_audit_info ad;
1447
	int rc = 0;
C
Casey Schaufler 已提交
1448
	struct inode *inode = file_inode(file);
E
Etienne Basset 已提交
1449

1450 1451
	switch (cmd) {
	case F_GETLK:
1452
		break;
1453 1454
	case F_SETLK:
	case F_SETLKW:
1455 1456
		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
1457
		rc = smk_curacc(smk_of_inode(inode), MAY_LOCK, &ad);
C
Casey Schaufler 已提交
1458
		rc = smk_bu_file(file, MAY_LOCK, rc);
1459
		break;
1460 1461
	case F_SETOWN:
	case F_SETSIG:
1462 1463
		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
1464
		rc = smk_curacc(smk_of_inode(inode), MAY_WRITE, &ad);
C
Casey Schaufler 已提交
1465
		rc = smk_bu_file(file, MAY_WRITE, rc);
1466 1467
		break;
	default:
1468
		break;
1469 1470 1471 1472 1473
	}

	return rc;
}

1474
/**
1475
 * smack_mmap_file :
1476 1477 1478 1479 1480 1481 1482 1483
 * 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.
 */
1484
static int smack_mmap_file(struct file *file,
1485
			   unsigned long reqprot, unsigned long prot,
1486
			   unsigned long flags)
1487
{
1488
	struct smack_known *skp;
1489
	struct smack_known *mkp;
1490 1491
	struct smack_rule *srp;
	struct task_smack *tsp;
1492
	struct smack_known *okp;
1493
	struct inode_smack *isp;
1494 1495 1496
	int may;
	int mmay;
	int tmay;
1497 1498
	int rc;

A
Al Viro 已提交
1499
	if (file == NULL)
1500 1501
		return 0;

A
Al Viro 已提交
1502
	isp = file_inode(file)->i_security;
1503 1504
	if (isp->smk_mmap == NULL)
		return 0;
1505
	mkp = isp->smk_mmap;
1506 1507

	tsp = current_security();
1508
	skp = smk_of_current();
1509 1510 1511 1512 1513 1514 1515 1516
	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.
	 */
1517
	list_for_each_entry_rcu(srp, &skp->smk_rules, list) {
1518
		okp = srp->smk_object;
1519 1520 1521
		/*
		 * Matching labels always allows access.
		 */
1522
		if (mkp->smk_known == okp->smk_known)
1523
			continue;
1524 1525 1526 1527
		/*
		 * If there is a matching local rule take
		 * that into account as well.
		 */
1528 1529 1530
		may = smk_access_entry(srp->smk_subject->smk_known,
				       okp->smk_known,
				       &tsp->smk_rules);
1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546
		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.
		 */
1547 1548
		mmay = smk_access_entry(mkp->smk_known, okp->smk_known,
					&mkp->smk_rules);
1549 1550 1551 1552 1553 1554 1555 1556
		if (mmay == -ENOENT) {
			rc = -EACCES;
			break;
		}
		/*
		 * If there is a local entry it modifies the
		 * potential access, too.
		 */
1557 1558
		tmay = smk_access_entry(mkp->smk_known, okp->smk_known,
					&tsp->smk_rules);
1559 1560
		if (tmay != -ENOENT)
			mmay &= tmay;
1561

1562 1563 1564 1565 1566
		/*
		 * If there is any access available to current that is
		 * not available to a SMACK64MMAP subject
		 * deny access.
		 */
1567
		if ((may | mmay) != mmay) {
1568
			rc = -EACCES;
1569
			break;
1570
		}
1571 1572 1573 1574 1575 1576 1577
	}

	rcu_read_unlock();

	return rc;
}

1578 1579 1580 1581 1582
/**
 * smack_file_set_fowner - set the file security blob value
 * @file: object in question
 *
 */
1583
static void smack_file_set_fowner(struct file *file)
1584
{
C
Casey Schaufler 已提交
1585
	file->f_security = smk_of_current();
1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601
}

/**
 * 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)
{
1602 1603
	struct smack_known *skp;
	struct smack_known *tkp = smk_of_task(tsk->cred->security);
1604 1605
	struct file *file;
	int rc;
E
Etienne Basset 已提交
1606
	struct smk_audit_info ad;
1607 1608 1609 1610 1611

	/*
	 * struct fown_struct is never outside the context of a struct file
	 */
	file = container_of(fown, struct file, f_owner);
1612

E
Etienne Basset 已提交
1613
	/* we don't log here as rc can be overriden */
1614 1615 1616
	skp = file->f_security;
	rc = smk_access(skp, tkp, MAY_WRITE, NULL);
	rc = smk_bu_note("sigiotask", skp, tkp, MAY_WRITE, rc);
1617
	if (rc != 0 && has_capability(tsk, CAP_MAC_OVERRIDE))
E
Etienne Basset 已提交
1618 1619 1620 1621
		rc = 0;

	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
	smk_ad_setfield_u_tsk(&ad, tsk);
1622
	smack_log(skp->smk_known, tkp->smk_known, MAY_WRITE, rc, &ad);
1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633
	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
1634
	int rc;
1635
	int may = 0;
E
Etienne Basset 已提交
1636
	struct smk_audit_info ad;
C
Casey Schaufler 已提交
1637
	struct inode *inode = file_inode(file);
1638

1639
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
E
Etienne Basset 已提交
1640
	smk_ad_setfield_u_fs_path(&ad, file->f_path);
1641 1642 1643 1644 1645 1646 1647 1648
	/*
	 * 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
1649
	rc = smk_curacc(smk_of_inode(inode), may, &ad);
C
Casey Schaufler 已提交
1650 1651
	rc = smk_bu_file(file, may, rc);
	return rc;
1652 1653
}

1654
/**
1655
 * smack_file_open - Smack dentry open processing
1656
 * @file: the object
1657
 * @cred: task credential
1658 1659
 *
 * Set the security blob in the file structure.
1660 1661 1662
 * 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.
1663 1664 1665
 *
 * Returns 0
 */
1666
static int smack_file_open(struct file *file, const struct cred *cred)
1667
{
1668
	struct task_smack *tsp = cred->security;
C
Casey Schaufler 已提交
1669
	struct inode *inode = file_inode(file);
1670 1671
	struct smk_audit_info ad;
	int rc;
1672

C
Casey Schaufler 已提交
1673
	if (smack_privileged(CAP_MAC_OVERRIDE))
1674
		return 0;
1675

1676 1677
	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
1678
	rc = smk_access(tsp->smk_task, smk_of_inode(inode), MAY_READ, &ad);
C
Casey Schaufler 已提交
1679
	rc = smk_bu_credfile(cred, file, MAY_READ, rc);
1680 1681

	return rc;
1682 1683
}

1684 1685 1686 1687
/*
 * Task hooks
 */

1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698
/**
 * 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)
{
1699 1700 1701 1702
	struct task_smack *tsp;

	tsp = new_task_smack(NULL, NULL, gfp);
	if (tsp == NULL)
1703
		return -ENOMEM;
1704 1705 1706

	cred->security = tsp;

1707 1708 1709 1710
	return 0;
}


1711
/**
1712 1713
 * smack_cred_free - "free" task-level security credentials
 * @cred: the credentials in question
1714 1715
 *
 */
1716
static void smack_cred_free(struct cred *cred)
1717
{
1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732
	struct task_smack *tsp = cred->security;
	struct smack_rule *rp;
	struct list_head *l;
	struct list_head *n;

	if (tsp == NULL)
		return;
	cred->security = NULL;

	list_for_each_safe(l, n, &tsp->smk_rules) {
		rp = list_entry(l, struct smack_rule, list);
		list_del(&rp->list);
		kfree(rp);
	}
	kfree(tsp);
1733 1734
}

D
David Howells 已提交
1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745
/**
 * 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)
{
1746 1747
	struct task_smack *old_tsp = old->security;
	struct task_smack *new_tsp;
1748
	int rc;
1749

1750
	new_tsp = new_task_smack(old_tsp->smk_task, old_tsp->smk_task, gfp);
1751 1752 1753
	if (new_tsp == NULL)
		return -ENOMEM;

1754 1755 1756 1757
	rc = smk_copy_rules(&new_tsp->smk_rules, &old_tsp->smk_rules, gfp);
	if (rc != 0)
		return rc;

1758
	new->security = new_tsp;
D
David Howells 已提交
1759 1760 1761
	return 0;
}

1762 1763 1764 1765 1766 1767 1768 1769 1770
/**
 * 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)
{
1771 1772 1773 1774 1775
	struct task_smack *old_tsp = old->security;
	struct task_smack *new_tsp = new->security;

	new_tsp->smk_task = old_tsp->smk_task;
	new_tsp->smk_forked = old_tsp->smk_task;
1776 1777 1778 1779 1780
	mutex_init(&new_tsp->smk_rules_lock);
	INIT_LIST_HEAD(&new_tsp->smk_rules);


	/* cbs copy rule list */
1781 1782
}

1783 1784
/**
 * smack_kernel_act_as - Set the subjective context in a set of credentials
1785 1786
 * @new: points to the set of credentials to be modified.
 * @secid: specifies the security ID to be set
1787 1788 1789 1790 1791
 *
 * Set the security data for a kernel service.
 */
static int smack_kernel_act_as(struct cred *new, u32 secid)
{
1792
	struct task_smack *new_tsp = new->security;
1793
	struct smack_known *skp = smack_from_secid(secid);
1794

1795
	if (skp == NULL)
1796 1797
		return -EINVAL;

1798
	new_tsp->smk_task = skp;
1799 1800 1801 1802 1803
	return 0;
}

/**
 * smack_kernel_create_files_as - Set the file creation label in a set of creds
1804 1805
 * @new: points to the set of credentials to be modified
 * @inode: points to the inode to use as a reference
1806 1807 1808 1809 1810 1811 1812 1813
 *
 * 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)
{
	struct inode_smack *isp = inode->i_security;
1814
	struct task_smack *tsp = new->security;
1815

1816
	tsp->smk_forked = isp->smk_inode;
1817
	tsp->smk_task = tsp->smk_forked;
1818 1819 1820
	return 0;
}

E
Etienne Basset 已提交
1821 1822 1823
/**
 * smk_curacc_on_task - helper to log task related access
 * @p: the task object
1824 1825
 * @access: the access requested
 * @caller: name of the calling function for audit
E
Etienne Basset 已提交
1826 1827 1828
 *
 * Return 0 if access is permitted
 */
1829 1830
static int smk_curacc_on_task(struct task_struct *p, int access,
				const char *caller)
E
Etienne Basset 已提交
1831 1832
{
	struct smk_audit_info ad;
1833
	struct smack_known *skp = smk_of_task(task_security(p));
C
Casey Schaufler 已提交
1834
	int rc;
E
Etienne Basset 已提交
1835

1836
	smk_ad_init(&ad, caller, LSM_AUDIT_DATA_TASK);
E
Etienne Basset 已提交
1837
	smk_ad_setfield_u_tsk(&ad, p);
1838
	rc = smk_curacc(skp, access, &ad);
C
Casey Schaufler 已提交
1839 1840
	rc = smk_bu_task(p, access, rc);
	return rc;
E
Etienne Basset 已提交
1841 1842
}

1843 1844 1845 1846 1847 1848 1849 1850 1851
/**
 * 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)
{
1852
	return smk_curacc_on_task(p, MAY_WRITE, __func__);
1853 1854 1855 1856 1857 1858 1859 1860 1861 1862
}

/**
 * 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)
{
1863
	return smk_curacc_on_task(p, MAY_READ, __func__);
1864 1865 1866 1867 1868 1869 1870 1871 1872 1873
}

/**
 * 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)
{
1874
	return smk_curacc_on_task(p, MAY_READ, __func__);
1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885
}

/**
 * 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)
{
1886 1887 1888
	struct smack_known *skp = smk_of_task(task_security(p));

	*secid = skp->smk_secid;
1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899
}

/**
 * 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)
{
1900 1901 1902 1903
	int rc;

	rc = cap_task_setnice(p, nice);
	if (rc == 0)
1904
		rc = smk_curacc_on_task(p, MAY_WRITE, __func__);
1905
	return rc;
1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916
}

/**
 * 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)
{
1917 1918 1919 1920
	int rc;

	rc = cap_task_setioprio(p, ioprio);
	if (rc == 0)
1921
		rc = smk_curacc_on_task(p, MAY_WRITE, __func__);
1922
	return rc;
1923 1924 1925 1926 1927 1928 1929 1930 1931 1932
}

/**
 * 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)
{
1933
	return smk_curacc_on_task(p, MAY_READ, __func__);
1934 1935 1936 1937 1938 1939 1940 1941 1942 1943
}

/**
 * smack_task_setscheduler - Smack check on setting scheduler
 * @p: the task object
 * @policy: unused
 * @lp: unused
 *
 * Return 0 if read access is permitted
 */
1944
static int smack_task_setscheduler(struct task_struct *p)
1945
{
1946 1947
	int rc;

1948
	rc = cap_task_setscheduler(p);
1949
	if (rc == 0)
1950
		rc = smk_curacc_on_task(p, MAY_WRITE, __func__);
1951
	return rc;
1952 1953 1954 1955 1956 1957 1958 1959 1960 1961
}

/**
 * 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)
{
1962
	return smk_curacc_on_task(p, MAY_READ, __func__);
1963 1964 1965 1966 1967 1968 1969 1970 1971 1972
}

/**
 * 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)
{
1973
	return smk_curacc_on_task(p, MAY_WRITE, __func__);
1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990
}

/**
 * smack_task_kill - Smack check on signal delivery
 * @p: the task object
 * @info: unused
 * @sig: unused
 * @secid: identifies the smack to use in lieu of current's
 *
 * Return 0 if write access is permitted
 *
 * The secid behavior is an artifact of an SELinux hack
 * in the USB code. Someday it may go away.
 */
static int smack_task_kill(struct task_struct *p, struct siginfo *info,
			   int sig, u32 secid)
{
E
Etienne Basset 已提交
1991
	struct smk_audit_info ad;
1992 1993
	struct smack_known *skp;
	struct smack_known *tkp = smk_of_task(task_security(p));
C
Casey Schaufler 已提交
1994
	int rc;
E
Etienne Basset 已提交
1995 1996 1997

	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
	smk_ad_setfield_u_tsk(&ad, p);
1998 1999 2000 2001
	/*
	 * Sending a signal requires that the sender
	 * can write the receiver.
	 */
C
Casey Schaufler 已提交
2002
	if (secid == 0) {
2003
		rc = smk_curacc(tkp, MAY_WRITE, &ad);
C
Casey Schaufler 已提交
2004 2005 2006
		rc = smk_bu_task(p, MAY_WRITE, rc);
		return rc;
	}
2007 2008 2009 2010 2011
	/*
	 * If the secid isn't 0 we're dealing with some USB IO
	 * specific behavior. This is not clean. For one thing
	 * we can't take privilege into account.
	 */
2012
	skp = smack_from_secid(secid);
2013 2014
	rc = smk_access(skp, tkp, MAY_WRITE, &ad);
	rc = smk_bu_note("USB signal", skp, tkp, MAY_WRITE, rc);
C
Casey Schaufler 已提交
2015
	return rc;
2016 2017 2018 2019 2020 2021
}

/**
 * smack_task_wait - Smack access check for waiting
 * @p: task to wait for
 *
2022
 * Returns 0
2023 2024 2025 2026
 */
static int smack_task_wait(struct task_struct *p)
{
	/*
2027 2028 2029 2030 2031 2032
	 * Allow the operation to succeed.
	 * Zombies are bad.
	 * In userless environments (e.g. phones) programs
	 * get marked with SMACK64EXEC and even if the parent
	 * and child shouldn't be talking the parent still
	 * may expect to know when the child exits.
2033
	 */
2034
	return 0;
2035 2036 2037 2038 2039
}

/**
 * smack_task_to_inode - copy task smack into the inode blob
 * @p: task to copy from
2040
 * @inode: inode to copy to
2041 2042 2043 2044 2045 2046
 *
 * Sets the smack pointer in the inode security blob
 */
static void smack_task_to_inode(struct task_struct *p, struct inode *inode)
{
	struct inode_smack *isp = inode->i_security;
2047 2048
	struct smack_known *skp = smk_of_task(task_security(p));

2049
	isp->smk_inode = skp;
2050 2051 2052 2053 2054 2055 2056 2057 2058 2059
}

/*
 * Socket hooks.
 */

/**
 * smack_sk_alloc_security - Allocate a socket blob
 * @sk: the socket
 * @family: unused
2060
 * @gfp_flags: memory allocation flags
2061 2062 2063 2064 2065 2066 2067
 *
 * 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)
{
2068
	struct smack_known *skp = smk_of_current();
2069 2070 2071 2072 2073 2074
	struct socket_smack *ssp;

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

2075
	ssp->smk_in = skp;
2076
	ssp->smk_out = skp;
2077
	ssp->smk_packet = NULL;
2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094

	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)
{
	kfree(sk->sk_security);
}

2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106
/**
* smack_host_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.
*/
2107
static struct smack_known *smack_host_label(struct sockaddr_in *sip)
2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121
{
	struct smk_netlbladdr *snp;
	struct in_addr *siap = &sip->sin_addr;

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

	list_for_each_entry_rcu(snp, &smk_netlbladdr_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.sin_addr)->s_addr ==
2122 2123
		    (siap->s_addr & (&snp->smk_mask)->s_addr)) {
			/* we have found the special CIPSO option */
2124
			if (snp->smk_label == &smack_cipso_option)
2125
				return NULL;
2126
			return snp->smk_label;
2127
		}
2128 2129 2130 2131

	return NULL;
}

2132 2133 2134
/**
 * smack_netlabel - Set the secattr on a socket
 * @sk: the socket
2135
 * @labeled: socket label scheme
2136 2137 2138 2139 2140 2141
 *
 * Convert the outbound smack value (smk_out) to a
 * secattr and attach it to the socket.
 *
 * Returns 0 on success or an error code
 */
2142
static int smack_netlabel(struct sock *sk, int labeled)
2143
{
2144
	struct smack_known *skp;
2145
	struct socket_smack *ssp = sk->sk_security;
2146
	int rc = 0;
2147

2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162
	/*
	 * 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 {
2163
		skp = ssp->smk_out;
2164
		rc = netlbl_sock_setattr(sk, sk->sk_family, &skp->smk_netlabel);
2165 2166 2167 2168
	}

	bh_unlock_sock(sk);
	local_bh_enable();
2169

2170 2171 2172
	return rc;
}

2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185
/**
 * 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)
{
2186
	struct smack_known *skp;
2187 2188
	int rc;
	int sk_lbl;
2189
	struct smack_known *hkp;
2190
	struct socket_smack *ssp = sk->sk_security;
E
Etienne Basset 已提交
2191
	struct smk_audit_info ad;
2192 2193

	rcu_read_lock();
2194 2195
	hkp = smack_host_label(sap);
	if (hkp != NULL) {
E
Etienne Basset 已提交
2196
#ifdef CONFIG_AUDIT
2197 2198
		struct lsm_network_audit net;

2199 2200 2201 2202
		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
2203
#endif
2204
		sk_lbl = SMACK_UNLABELED_SOCKET;
2205
		skp = ssp->smk_out;
2206 2207
		rc = smk_access(skp, hkp, MAY_WRITE, &ad);
		rc = smk_bu_note("IPv4 host check", skp, hkp, MAY_WRITE, rc);
2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218
	} else {
		sk_lbl = SMACK_CIPSO_SOCKET;
		rc = 0;
	}
	rcu_read_unlock();
	if (rc != 0)
		return rc;

	return smack_netlabel(sk, sk_lbl);
}

2219
#if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299
/**
 * 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.
		 */
		list_for_each_entry(spp, &smk_ipv6_port_list, list) {
			if (sk != spp->smk_sock)
				continue;
			spp->smk_in = ssp->smk_in;
			spp->smk_out = ssp->smk_out;
			return;
		}
		/*
		 * A NULL address is only used for updating existing
		 * bound entries. If there isn't one, it's OK.
		 */
		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.
	 */
	list_for_each_entry(spp, &smk_ipv6_port_list, list) {
		if (spp->smk_port != port)
			continue;
		spp->smk_port = port;
		spp->smk_sock = sk;
		spp->smk_in = ssp->smk_in;
		spp->smk_out = ssp->smk_out;
		return;
	}

	/*
	 * 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;

	list_add(&spp->list, &smk_ipv6_port_list);
	return;
}

/**
 * smk_ipv6_port_check - check Smack port access
 * @sock: socket
 * @address: address
 *
 * Create or update the port list entry
 */
2300
static int smk_ipv6_port_check(struct sock *sk, struct sockaddr_in6 *address,
2301 2302 2303 2304 2305 2306
				int act)
{
	__be16 *bep;
	__be32 *be32p;
	struct smk_port_label *spp;
	struct socket_smack *ssp = sk->sk_security;
2307
	struct smack_known *skp;
2308
	unsigned short port = 0;
2309
	struct smack_known *object;
2310
	struct smk_audit_info ad;
C
Casey Schaufler 已提交
2311
	int rc;
2312 2313 2314 2315 2316
#ifdef CONFIG_AUDIT
	struct lsm_network_audit net;
#endif

	if (act == SMK_RECEIVING) {
2317
		skp = smack_net_ambient;
2318
		object = ssp->smk_in;
2319
	} else {
2320
		skp = ssp->smk_out;
2321
		object = smack_net_ambient;
2322 2323 2324 2325 2326
	}

	/*
	 * Get the IP address and port from the address.
	 */
2327 2328 2329
	port = ntohs(address->sin6_port);
	bep = (__be16 *)(&address->sin6_addr);
	be32p = (__be32 *)(&address->sin6_addr);
2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340

	/*
	 * It's remote, so port lookup does no good.
	 */
	if (be32p[0] || be32p[1] || be32p[2] || bep[6] || ntohs(bep[7]) != 1)
		goto auditout;

	/*
	 * It's local so the send check has to have passed.
	 */
	if (act == SMK_RECEIVING) {
2341
		skp = &smack_known_web;
2342 2343 2344 2345 2346 2347
		goto auditout;
	}

	list_for_each_entry(spp, &smk_ipv6_port_list, list) {
		if (spp->smk_port != port)
			continue;
2348
		object = spp->smk_in;
2349
		if (act == SMK_CONNECTING)
2350
			ssp->smk_packet = spp->smk_out;
2351 2352 2353 2354 2355 2356 2357 2358 2359 2360
		break;
	}

auditout:

#ifdef CONFIG_AUDIT
	smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
	ad.a.u.net->family = sk->sk_family;
	ad.a.u.net->dport = port;
	if (act == SMK_RECEIVING)
2361
		ad.a.u.net->v6info.saddr = address->sin6_addr;
2362
	else
2363
		ad.a.u.net->v6info.daddr = address->sin6_addr;
2364
#endif
C
Casey Schaufler 已提交
2365 2366 2367
	rc = smk_access(skp, object, MAY_WRITE, &ad);
	rc = smk_bu_note("IPv6 port check", skp, object, MAY_WRITE, rc);
	return rc;
2368
}
2369
#endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */
2370

2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385
/**
 * 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)
{
2386
	struct smack_known *skp;
2387 2388 2389
	struct inode_smack *nsp = inode->i_security;
	struct socket_smack *ssp;
	struct socket *sock;
2390
	int rc = 0;
2391

2392
	if (value == NULL || size > SMK_LONGLABEL || size == 0)
P
Pankaj Kumar 已提交
2393
		return -EINVAL;
2394

2395 2396
	skp = smk_import_entry(value, size);
	if (skp == NULL)
2397 2398 2399
		return -EINVAL;

	if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
2400
		nsp->smk_inode = skp;
2401
		nsp->smk_flags |= SMK_INODE_INSTANT;
2402 2403 2404 2405 2406 2407 2408 2409 2410
		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);
2411
	if (sock == NULL || sock->sk == NULL)
2412 2413 2414 2415 2416
		return -EOPNOTSUPP;

	ssp = sock->sk->sk_security;

	if (strcmp(name, XATTR_SMACK_IPIN) == 0)
2417
		ssp->smk_in = skp;
2418
	else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) {
2419
		ssp->smk_out = skp;
2420
		if (sock->sk->sk_family == PF_INET) {
C
Casey Schaufler 已提交
2421 2422 2423 2424 2425 2426
			rc = smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
			if (rc != 0)
				printk(KERN_WARNING
					"Smack: \"%s\" netlbl error %d.\n",
					__func__, -rc);
		}
2427 2428 2429
	} else
		return -EOPNOTSUPP;

2430
#if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
2431 2432
	if (sock->sk->sk_family == PF_INET6)
		smk_ipv6_port_label(sock, NULL);
2433
#endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */
2434

2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452
	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)
{
2453
	if (family != PF_INET || sock->sk == NULL)
2454 2455 2456 2457
		return 0;
	/*
	 * Set the outbound netlbl.
	 */
2458 2459 2460
	return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
}

2461
#ifndef CONFIG_SECURITY_SMACK_NETFILTER
2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474
/**
 * 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.
 *
 * Returns 0
 */
static int smack_socket_bind(struct socket *sock, struct sockaddr *address,
				int addrlen)
{
2475
#if IS_ENABLED(CONFIG_IPV6)
2476 2477
	if (sock->sk != NULL && sock->sk->sk_family == PF_INET6)
		smk_ipv6_port_label(sock, address);
2478
#endif
2479 2480 2481

	return 0;
}
2482
#endif /* !CONFIG_SECURITY_SMACK_NETFILTER */
2483

2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496
/**
 * 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)
{
2497 2498 2499
	int rc = 0;

	if (sock->sk == NULL)
2500 2501
		return 0;

2502 2503 2504 2505 2506 2507 2508 2509 2510
	switch (sock->sk->sk_family) {
	case PF_INET:
		if (addrlen < sizeof(struct sockaddr_in))
			return -EINVAL;
		rc = smack_netlabel_send(sock->sk, (struct sockaddr_in *)sap);
		break;
	case PF_INET6:
		if (addrlen < sizeof(struct sockaddr_in6))
			return -EINVAL;
2511
#if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
2512 2513
		rc = smk_ipv6_port_check(sock->sk, (struct sockaddr_in6 *)sap,
						SMK_CONNECTING);
2514
#endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */
2515 2516 2517
		break;
	}
	return rc;
2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 2529 2530 2531 2532 2533 2534 2535 2536 2537 2538 2539 2540 2541 2542 2543 2544 2545 2546 2547
}

/**
 * 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)
{
2548 2549
	struct smack_known *skp = smk_of_current();

2550
	msg->security = skp;
2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565 2566 2567 2568 2569 2570
	return 0;
}

/**
 * smack_msg_msg_free_security - Clear the security blob for msg_msg
 * @msg: the object
 *
 * Clears the blob pointer
 */
static void smack_msg_msg_free_security(struct msg_msg *msg)
{
	msg->security = NULL;
}

/**
 * smack_of_shm - the smack pointer for the shm
 * @shp: the object
 *
 * Returns a pointer to the smack value
 */
2571
static struct smack_known *smack_of_shm(struct shmid_kernel *shp)
2572
{
2573
	return (struct smack_known *)shp->shm_perm.security;
2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584
}

/**
 * smack_shm_alloc_security - Set the security blob for shm
 * @shp: the object
 *
 * Returns 0
 */
static int smack_shm_alloc_security(struct shmid_kernel *shp)
{
	struct kern_ipc_perm *isp = &shp->shm_perm;
2585
	struct smack_known *skp = smk_of_current();
2586

2587
	isp->security = skp;
2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602 2603
	return 0;
}

/**
 * smack_shm_free_security - Clear the security blob for shm
 * @shp: the object
 *
 * Clears the blob pointer
 */
static void smack_shm_free_security(struct shmid_kernel *shp)
{
	struct kern_ipc_perm *isp = &shp->shm_perm;

	isp->security = NULL;
}

E
Etienne Basset 已提交
2604 2605 2606 2607 2608 2609 2610 2611 2612
/**
 * smk_curacc_shm : check if current has access on shm
 * @shp : the object
 * @access : access requested
 *
 * Returns 0 if current has the requested access, error code otherwise
 */
static int smk_curacc_shm(struct shmid_kernel *shp, int access)
{
2613
	struct smack_known *ssp = smack_of_shm(shp);
E
Etienne Basset 已提交
2614
	struct smk_audit_info ad;
C
Casey Schaufler 已提交
2615
	int rc;
E
Etienne Basset 已提交
2616 2617 2618 2619 2620

#ifdef CONFIG_AUDIT
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
	ad.a.u.ipc_id = shp->shm_perm.id;
#endif
C
Casey Schaufler 已提交
2621 2622 2623
	rc = smk_curacc(ssp, access, &ad);
	rc = smk_bu_current("shm", ssp, access, rc);
	return rc;
E
Etienne Basset 已提交
2624 2625
}

2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 2636 2637
/**
 * smack_shm_associate - Smack access check for shm
 * @shp: the object
 * @shmflg: access requested
 *
 * Returns 0 if current has the requested access, error code otherwise
 */
static int smack_shm_associate(struct shmid_kernel *shp, int shmflg)
{
	int may;

	may = smack_flags_to_may(shmflg);
E
Etienne Basset 已提交
2638
	return smk_curacc_shm(shp, may);
2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650 2651 2652 2653 2654 2655 2656 2657 2658 2659 2660 2661 2662 2663 2664 2665 2666 2667 2668 2669 2670 2671
}

/**
 * smack_shm_shmctl - Smack access check for shm
 * @shp: the object
 * @cmd: what it wants to do
 *
 * Returns 0 if current has the requested access, error code otherwise
 */
static int smack_shm_shmctl(struct shmid_kernel *shp, int cmd)
{
	int may;

	switch (cmd) {
	case IPC_STAT:
	case SHM_STAT:
		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;
	}
E
Etienne Basset 已提交
2672
	return smk_curacc_shm(shp, may);
2673 2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686 2687 2688
}

/**
 * smack_shm_shmat - Smack access for shmat
 * @shp: the object
 * @shmaddr: unused
 * @shmflg: access requested
 *
 * Returns 0 if current has the requested access, error code otherwise
 */
static int smack_shm_shmat(struct shmid_kernel *shp, char __user *shmaddr,
			   int shmflg)
{
	int may;

	may = smack_flags_to_may(shmflg);
E
Etienne Basset 已提交
2689
	return smk_curacc_shm(shp, may);
2690 2691 2692 2693 2694 2695 2696 2697
}

/**
 * smack_of_sem - the smack pointer for the sem
 * @sma: the object
 *
 * Returns a pointer to the smack value
 */
2698
static struct smack_known *smack_of_sem(struct sem_array *sma)
2699
{
2700
	return (struct smack_known *)sma->sem_perm.security;
2701 2702 2703 2704 2705 2706 2707 2708 2709 2710 2711
}

/**
 * smack_sem_alloc_security - Set the security blob for sem
 * @sma: the object
 *
 * Returns 0
 */
static int smack_sem_alloc_security(struct sem_array *sma)
{
	struct kern_ipc_perm *isp = &sma->sem_perm;
2712
	struct smack_known *skp = smk_of_current();
2713

2714
	isp->security = skp;
2715 2716 2717 2718 2719 2720 2721 2722 2723 2724 2725 2726 2727 2728 2729 2730
	return 0;
}

/**
 * smack_sem_free_security - Clear the security blob for sem
 * @sma: the object
 *
 * Clears the blob pointer
 */
static void smack_sem_free_security(struct sem_array *sma)
{
	struct kern_ipc_perm *isp = &sma->sem_perm;

	isp->security = NULL;
}

E
Etienne Basset 已提交
2731 2732 2733 2734 2735 2736 2737 2738 2739
/**
 * smk_curacc_sem : check if current has access on sem
 * @sma : the object
 * @access : access requested
 *
 * Returns 0 if current has the requested access, error code otherwise
 */
static int smk_curacc_sem(struct sem_array *sma, int access)
{
2740
	struct smack_known *ssp = smack_of_sem(sma);
E
Etienne Basset 已提交
2741
	struct smk_audit_info ad;
C
Casey Schaufler 已提交
2742
	int rc;
E
Etienne Basset 已提交
2743 2744 2745 2746 2747

#ifdef CONFIG_AUDIT
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
	ad.a.u.ipc_id = sma->sem_perm.id;
#endif
C
Casey Schaufler 已提交
2748 2749 2750
	rc = smk_curacc(ssp, access, &ad);
	rc = smk_bu_current("sem", ssp, access, rc);
	return rc;
E
Etienne Basset 已提交
2751 2752
}

2753 2754 2755 2756 2757 2758 2759 2760 2761 2762 2763 2764
/**
 * smack_sem_associate - Smack access check for sem
 * @sma: the object
 * @semflg: access requested
 *
 * Returns 0 if current has the requested access, error code otherwise
 */
static int smack_sem_associate(struct sem_array *sma, int semflg)
{
	int may;

	may = smack_flags_to_may(semflg);
E
Etienne Basset 已提交
2765
	return smk_curacc_sem(sma, may);
2766 2767 2768 2769 2770 2771 2772 2773 2774 2775 2776 2777 2778 2779 2780 2781 2782 2783 2784 2785 2786 2787 2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 2799 2800 2801 2802 2803 2804
}

/**
 * smack_sem_shmctl - Smack access check for sem
 * @sma: the object
 * @cmd: what it wants to do
 *
 * Returns 0 if current has the requested access, error code otherwise
 */
static int smack_sem_semctl(struct sem_array *sma, int cmd)
{
	int may;

	switch (cmd) {
	case GETPID:
	case GETNCNT:
	case GETZCNT:
	case GETVAL:
	case GETALL:
	case IPC_STAT:
	case SEM_STAT:
		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;
	}

E
Etienne Basset 已提交
2805
	return smk_curacc_sem(sma, may);
2806 2807 2808 2809 2810 2811 2812 2813 2814 2815 2816 2817 2818 2819 2820 2821
}

/**
 * smack_sem_semop - Smack checks of semaphore operations
 * @sma: the object
 * @sops: unused
 * @nsops: unused
 * @alter: unused
 *
 * Treated as read and write in all cases.
 *
 * Returns 0 if access is allowed, error code otherwise
 */
static int smack_sem_semop(struct sem_array *sma, struct sembuf *sops,
			   unsigned nsops, int alter)
{
E
Etienne Basset 已提交
2822
	return smk_curacc_sem(sma, MAY_READWRITE);
2823 2824 2825 2826 2827 2828 2829 2830 2831 2832 2833
}

/**
 * smack_msg_alloc_security - Set the security blob for msg
 * @msq: the object
 *
 * Returns 0
 */
static int smack_msg_queue_alloc_security(struct msg_queue *msq)
{
	struct kern_ipc_perm *kisp = &msq->q_perm;
2834
	struct smack_known *skp = smk_of_current();
2835

2836
	kisp->security = skp;
2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855 2856
	return 0;
}

/**
 * smack_msg_free_security - Clear the security blob for msg
 * @msq: the object
 *
 * Clears the blob pointer
 */
static void smack_msg_queue_free_security(struct msg_queue *msq)
{
	struct kern_ipc_perm *kisp = &msq->q_perm;

	kisp->security = NULL;
}

/**
 * smack_of_msq - the smack pointer for the msq
 * @msq: the object
 *
2857
 * Returns a pointer to the smack label entry
2858
 */
2859
static struct smack_known *smack_of_msq(struct msg_queue *msq)
2860
{
2861
	return (struct smack_known *)msq->q_perm.security;
2862 2863
}

E
Etienne Basset 已提交
2864 2865 2866 2867 2868 2869 2870 2871 2872
/**
 * smk_curacc_msq : helper to check if current has access on msq
 * @msq : the msq
 * @access : access requested
 *
 * return 0 if current has access, error otherwise
 */
static int smk_curacc_msq(struct msg_queue *msq, int access)
{
2873
	struct smack_known *msp = smack_of_msq(msq);
E
Etienne Basset 已提交
2874
	struct smk_audit_info ad;
C
Casey Schaufler 已提交
2875
	int rc;
E
Etienne Basset 已提交
2876 2877 2878 2879 2880

#ifdef CONFIG_AUDIT
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
	ad.a.u.ipc_id = msq->q_perm.id;
#endif
C
Casey Schaufler 已提交
2881 2882 2883
	rc = smk_curacc(msp, access, &ad);
	rc = smk_bu_current("msq", msp, access, rc);
	return rc;
E
Etienne Basset 已提交
2884 2885
}

2886 2887 2888 2889 2890 2891 2892 2893 2894 2895 2896 2897
/**
 * smack_msg_queue_associate - Smack access check for msg_queue
 * @msq: the object
 * @msqflg: access requested
 *
 * Returns 0 if current has the requested access, error code otherwise
 */
static int smack_msg_queue_associate(struct msg_queue *msq, int msqflg)
{
	int may;

	may = smack_flags_to_may(msqflg);
E
Etienne Basset 已提交
2898
	return smk_curacc_msq(msq, may);
2899 2900 2901 2902 2903 2904 2905 2906 2907 2908 2909 2910 2911 2912 2913 2914 2915 2916 2917 2918 2919 2920 2921 2922 2923 2924 2925 2926 2927 2928 2929 2930
}

/**
 * smack_msg_queue_msgctl - Smack access check for msg_queue
 * @msq: the object
 * @cmd: what it wants to do
 *
 * Returns 0 if current has the requested access, error code otherwise
 */
static int smack_msg_queue_msgctl(struct msg_queue *msq, int cmd)
{
	int may;

	switch (cmd) {
	case IPC_STAT:
	case MSG_STAT:
		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;
	}

E
Etienne Basset 已提交
2931
	return smk_curacc_msq(msq, may);
2932 2933 2934 2935 2936 2937 2938 2939 2940 2941 2942 2943 2944
}

/**
 * smack_msg_queue_msgsnd - Smack access check for msg_queue
 * @msq: the object
 * @msg: unused
 * @msqflg: access requested
 *
 * Returns 0 if current has the requested access, error code otherwise
 */
static int smack_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg,
				  int msqflg)
{
E
Etienne Basset 已提交
2945
	int may;
2946

E
Etienne Basset 已提交
2947 2948
	may = smack_flags_to_may(msqflg);
	return smk_curacc_msq(msq, may);
2949 2950 2951 2952 2953 2954 2955 2956 2957 2958 2959 2960 2961 2962 2963
}

/**
 * smack_msg_queue_msgsnd - Smack access check for msg_queue
 * @msq: the object
 * @msg: unused
 * @target: unused
 * @type: unused
 * @mode: unused
 *
 * Returns 0 if current has read and write access, error code otherwise
 */
static int smack_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
			struct task_struct *target, long type, int mode)
{
E
Etienne Basset 已提交
2964
	return smk_curacc_msq(msq, MAY_READWRITE);
2965 2966 2967 2968 2969 2970 2971 2972 2973 2974 2975
}

/**
 * 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)
{
2976
	struct smack_known *iskp = ipp->security;
E
Etienne Basset 已提交
2977 2978
	int may = smack_flags_to_may(flag);
	struct smk_audit_info ad;
C
Casey Schaufler 已提交
2979
	int rc;
2980

E
Etienne Basset 已提交
2981 2982 2983 2984
#ifdef CONFIG_AUDIT
	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
	ad.a.u.ipc_id = ipp->id;
#endif
2985 2986
	rc = smk_curacc(iskp, may, &ad);
	rc = smk_bu_current("svipc", iskp, may, rc);
C
Casey Schaufler 已提交
2987
	return rc;
2988 2989
}

2990 2991
/**
 * smack_ipc_getsecid - Extract smack security id
2992
 * @ipp: the object permissions
2993 2994 2995 2996
 * @secid: where result will be saved
 */
static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid)
{
2997
	struct smack_known *iskp = ipp->security;
2998

2999
	*secid = iskp->smk_secid;
3000 3001
}

3002 3003
/**
 * smack_d_instantiate - Make sure the blob is correct on an inode
3004
 * @opt_dentry: dentry where inode will be attached
3005 3006 3007 3008 3009 3010 3011 3012 3013
 * @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;
3014 3015
	struct smack_known *skp;
	struct smack_known *ckp = smk_of_current();
3016
	struct smack_known *final;
3017 3018
	char trattr[TRANS_TRUE_SIZE];
	int transflag = 0;
C
Casey Schaufler 已提交
3019
	int rc;
3020 3021 3022 3023 3024 3025 3026 3027 3028 3029 3030 3031 3032 3033 3034 3035 3036 3037 3038 3039 3040 3041 3042
	struct dentry *dp;

	if (inode == NULL)
		return;

	isp = inode->i_security;

	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
3043 3044 3045 3046 3047 3048 3049
	/*
	 * 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) {
3050 3051
		switch (sbp->s_magic) {
		case CGROUP_SUPER_MAGIC:
3052 3053 3054 3055 3056
			/*
			 * The cgroup filesystem is never mounted,
			 * so there's no opportunity to set the mount
			 * options.
			 */
3057 3058
			sbsp->smk_root = &smack_known_star;
			sbsp->smk_default = &smack_known_star;
3059 3060 3061 3062 3063 3064 3065 3066 3067 3068 3069 3070
			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;
		default:
			isp->smk_inode = sbsp->smk_root;
			break;
3071
		}
C
Casey Schaufler 已提交
3072 3073 3074 3075
		isp->smk_flags |= SMK_INODE_INSTANT;
		goto unlockandout;
	}

3076 3077 3078 3079 3080 3081 3082 3083
	/*
	 * 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:
3084 3085 3086
	case PIPEFS_MAGIC:
	case SOCKFS_MAGIC:
	case CGROUP_SUPER_MAGIC:
3087
		/*
L
Lucas De Marchi 已提交
3088
		 * Casey says that it's a little embarrassing
3089 3090
		 * that the smack file system doesn't do
		 * extended attributes.
3091
		 *
3092
		 * Casey says pipes are easy (?)
3093 3094 3095 3096 3097
		 *
		 * Socket access is controlled by the socket
		 * structures associated with the task involved.
		 *
		 * Cgroupfs is special
3098
		 */
3099
		final = &smack_known_star;
3100 3101 3102 3103 3104 3105 3106
		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.
		 */
3107
		final = ckp;
3108 3109 3110 3111 3112 3113 3114 3115 3116 3117 3118 3119 3120
		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.
		 */
3121
		final = &smack_known_star;
3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133
		/*
		 * No break.
		 *
		 * 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.
		 */
	default:
		/*
		 * This isn't an understood special case.
		 * Get the value from the xattr.
C
Casey Schaufler 已提交
3134 3135 3136 3137 3138 3139
		 */

		/*
		 * UNIX domain sockets use lower level socket data.
		 */
		if (S_ISSOCK(inode->i_mode)) {
3140
			final = &smack_known_star;
C
Casey Schaufler 已提交
3141 3142 3143
			break;
		}
		/*
3144 3145 3146 3147 3148 3149 3150 3151 3152 3153
		 * 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.
		 */
		if (inode->i_op->getxattr == NULL)
			break;
		/*
		 * Get the dentry for xattr.
		 */
3154
		dp = dget(opt_dentry);
3155 3156
		skp = smk_fetch(XATTR_NAME_SMACK, inode, dp);
		if (skp != NULL)
3157
			final = skp;
C
Casey Schaufler 已提交
3158 3159 3160 3161 3162 3163 3164 3165 3166 3167 3168 3169 3170 3171 3172 3173 3174

		/*
		 * 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;
				rc = inode->i_op->setxattr(dp,
3175
					XATTR_NAME_SMACKTRANSMUTE,
C
Casey Schaufler 已提交
3176 3177 3178 3179 3180 3181 3182 3183 3184
					TRANS_TRUE, TRANS_TRUE_SIZE,
					0);
			} else {
				rc = inode->i_op->getxattr(dp,
					XATTR_NAME_SMACKTRANSMUTE, trattr,
					TRANS_TRUE_SIZE);
				if (rc >= 0 && strncmp(trattr, TRANS_TRUE,
						       TRANS_TRUE_SIZE) != 0)
					rc = -EINVAL;
3185
			}
C
Casey Schaufler 已提交
3186 3187
			if (rc >= 0)
				transflag = SMK_INODE_TRANSMUTE;
3188
		}
3189 3190 3191 3192 3193 3194 3195 3196 3197 3198 3199
		/*
		 * Don't let the exec or mmap label be "*" or "@".
		 */
		skp = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp);
		if (skp == &smack_known_star || skp == &smack_known_web)
			skp = NULL;
		isp->smk_task = skp;
		skp = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp);
		if (skp == &smack_known_star || skp == &smack_known_web)
			skp = NULL;
		isp->smk_mmap = skp;
3200

3201 3202 3203 3204 3205
		dput(dp);
		break;
	}

	if (final == NULL)
3206
		isp->smk_inode = ckp;
3207 3208 3209
	else
		isp->smk_inode = final;

3210
	isp->smk_flags |= (SMK_INODE_INSTANT | transflag);
3211 3212 3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3223 3224 3225 3226 3227 3228

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)
{
3229
	struct smack_known *skp = smk_of_task(task_security(p));
3230 3231 3232 3233 3234 3235
	char *cp;
	int slen;

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

3236
	cp = kstrdup(skp->smk_known, GFP_KERNEL);
3237 3238 3239 3240 3241 3242 3243 3244 3245 3246 3247 3248 3249 3250 3251 3252 3253 3254 3255 3256 3257 3258 3259
	if (cp == NULL)
		return -ENOMEM;

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

/**
 * smack_setprocattr - Smack process attribute setting
 * @p: the object task
 * @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
 */
static int smack_setprocattr(struct task_struct *p, char *name,
			     void *value, size_t size)
{
3260
	struct task_smack *tsp;
D
David Howells 已提交
3261
	struct cred *new;
3262
	struct smack_known *skp;
3263 3264 3265 3266 3267 3268 3269 3270

	/*
	 * Changing another process' Smack value is too dangerous
	 * and supports no sane use case.
	 */
	if (p != current)
		return -EPERM;

3271
	if (!smack_privileged(CAP_MAC_ADMIN))
3272 3273
		return -EPERM;

3274
	if (value == NULL || size == 0 || size >= SMK_LONGLABEL)
3275 3276 3277 3278 3279
		return -EINVAL;

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

3280 3281
	skp = smk_import_entry(value, size);
	if (skp == NULL)
3282 3283
		return -EINVAL;

3284 3285 3286
	/*
	 * No process is ever allowed the web ("@") label.
	 */
3287
	if (skp == &smack_known_web)
3288 3289
		return -EPERM;

D
David Howells 已提交
3290
	new = prepare_creds();
3291
	if (new == NULL)
D
David Howells 已提交
3292
		return -ENOMEM;
3293

3294
	tsp = new->security;
3295
	tsp->smk_task = skp;
3296

D
David Howells 已提交
3297
	commit_creds(new);
3298 3299 3300 3301 3302
	return size;
}

/**
 * smack_unix_stream_connect - Smack access on UDS
3303 3304
 * @sock: one sock
 * @other: the other sock
3305 3306 3307 3308 3309
 * @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
 */
3310 3311
static int smack_unix_stream_connect(struct sock *sock,
				     struct sock *other, struct sock *newsk)
3312
{
3313
	struct smack_known *skp;
3314
	struct smack_known *okp;
J
James Morris 已提交
3315 3316
	struct socket_smack *ssp = sock->sk_security;
	struct socket_smack *osp = other->sk_security;
3317
	struct socket_smack *nsp = newsk->sk_security;
E
Etienne Basset 已提交
3318
	struct smk_audit_info ad;
C
Casey Schaufler 已提交
3319
	int rc = 0;
3320 3321 3322
#ifdef CONFIG_AUDIT
	struct lsm_network_audit net;
#endif
C
Casey Schaufler 已提交
3323

3324 3325
	if (!smack_privileged(CAP_MAC_OVERRIDE)) {
		skp = ssp->smk_out;
3326
		okp = osp->smk_in;
3327 3328 3329 3330
#ifdef CONFIG_AUDIT
		smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
		smk_ad_setfield_u_net_sk(&ad, other);
#endif
3331 3332
		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
3333
		if (rc == 0) {
3334 3335
			okp = osp->smk_out;
			skp = ssp->smk_in;
3336 3337
			rc = smk_access(okp, skp, MAY_WRITE, NULL);
			rc = smk_bu_note("UDS connect", okp, skp,
C
Casey Schaufler 已提交
3338 3339
						MAY_WRITE, rc);
		}
3340
	}
C
Casey Schaufler 已提交
3341

3342 3343 3344 3345
	/*
	 * Cross reference the peer labels for SO_PEERSEC.
	 */
	if (rc == 0) {
3346 3347
		nsp->smk_packet = ssp->smk_out;
		ssp->smk_packet = osp->smk_out;
3348 3349
	}

C
Casey Schaufler 已提交
3350
	return rc;
3351 3352 3353 3354 3355 3356 3357 3358 3359 3360 3361 3362
}

/**
 * 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
3363 3364
	struct socket_smack *ssp = sock->sk->sk_security;
	struct socket_smack *osp = other->sk->sk_security;
E
Etienne Basset 已提交
3365
	struct smk_audit_info ad;
C
Casey Schaufler 已提交
3366
	int rc;
3367

3368 3369 3370
#ifdef CONFIG_AUDIT
	struct lsm_network_audit net;

3371
	smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
E
Etienne Basset 已提交
3372
	smk_ad_setfield_u_net_sk(&ad, other->sk);
3373
#endif
C
Casey Schaufler 已提交
3374

3375 3376
	if (smack_privileged(CAP_MAC_OVERRIDE))
		return 0;
C
Casey Schaufler 已提交
3377

3378 3379
	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
3380
	return rc;
3381 3382
}

3383 3384 3385
/**
 * smack_socket_sendmsg - Smack check based on destination host
 * @sock: the socket
3386
 * @msg: the message
3387 3388
 * @size: the size of the message
 *
3389 3390 3391
 * 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.
3392 3393 3394 3395 3396
 */
static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
				int size)
{
	struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name;
3397
#if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
3398
	struct sockaddr_in6 *sap = (struct sockaddr_in6 *) msg->msg_name;
3399
#endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */
3400
	int rc = 0;
3401 3402 3403 3404

	/*
	 * Perfectly reasonable for this to be NULL
	 */
3405
	if (sip == NULL)
3406 3407
		return 0;

3408 3409 3410 3411 3412
	switch (sip->sin_family) {
	case AF_INET:
		rc = smack_netlabel_send(sock->sk, sip);
		break;
	case AF_INET6:
3413
#if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
3414
		rc = smk_ipv6_port_check(sock->sk, sap, SMK_SENDING);
3415
#endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */
3416 3417 3418
		break;
	}
	return rc;
3419 3420
}

3421
/**
3422
 * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack
3423
 * @sap: netlabel secattr
3424
 * @ssp: socket security information
3425
 *
3426
 * Returns a pointer to a Smack label entry found on the label list.
3427
 */
3428 3429
static struct smack_known *smack_from_secattr(struct netlbl_lsm_secattr *sap,
						struct socket_smack *ssp)
3430
{
3431
	struct smack_known *skp;
3432
	int found = 0;
C
Casey Schaufler 已提交
3433 3434
	int acat;
	int kcat;
3435

3436
	if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) {
3437
		/*
3438
		 * Looks like a CIPSO packet.
3439 3440 3441
		 * If there are flags but no level netlabel isn't
		 * behaving the way we expect it to.
		 *
3442
		 * Look it up in the label table
3443 3444 3445 3446
		 * Without guidance regarding the smack value
		 * for the packet fall back on the network
		 * ambient value.
		 */
3447
		rcu_read_lock();
3448 3449
		list_for_each_entry(skp, &smack_known_list, list) {
			if (sap->attr.mls.lvl != skp->smk_netlabel.attr.mls.lvl)
3450
				continue;
C
Casey Schaufler 已提交
3451 3452 3453 3454 3455 3456 3457 3458 3459 3460
			/*
			 * 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; ) {
3461 3462 3463
				acat = netlbl_catmap_walk(sap->attr.mls.cat,
							  acat + 1);
				kcat = netlbl_catmap_walk(
C
Casey Schaufler 已提交
3464 3465 3466 3467 3468 3469 3470 3471 3472
					skp->smk_netlabel.attr.mls.cat,
					kcat + 1);
				if (acat < 0 || kcat < 0)
					break;
			}
			if (acat == kcat) {
				found = 1;
				break;
			}
3473
		}
3474 3475 3476
		rcu_read_unlock();

		if (found)
3477
			return skp;
3478

3479
		if (ssp != NULL && ssp->smk_in == &smack_known_star)
3480 3481
			return &smack_known_web;
		return &smack_known_star;
3482
	}
3483 3484 3485 3486
	if ((sap->flags & NETLBL_SECATTR_SECID) != 0) {
		/*
		 * Looks like a fallback, which gives us a secid.
		 */
3487
		skp = smack_from_secid(sap->attr.secid);
3488 3489 3490 3491 3492 3493 3494
		/*
		 * This has got to be a bug because it is
		 * impossible to specify a fallback without
		 * specifying the label, which will ensure
		 * it has a secid, and the only way to get a
		 * secid is from a fallback.
		 */
3495 3496
		BUG_ON(skp == NULL);
		return skp;
3497 3498
	}
	/*
3499 3500 3501
	 * Without guidance regarding the smack value
	 * for the packet fall back on the network
	 * ambient value.
3502
	 */
3503
	return smack_net_ambient;
3504 3505
}

3506
#if IS_ENABLED(CONFIG_IPV6)
3507
static int smk_skb_to_addr_ipv6(struct sk_buff *skb, struct sockaddr_in6 *sip)
3508 3509 3510 3511 3512 3513 3514 3515 3516 3517 3518 3519 3520 3521 3522 3523 3524 3525 3526 3527 3528 3529 3530 3531 3532 3533 3534 3535 3536 3537 3538 3539 3540 3541 3542 3543 3544 3545 3546 3547 3548 3549 3550 3551 3552
{
	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:
		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;
}
3553
#endif /* CONFIG_IPV6 */
3554

3555 3556 3557 3558 3559 3560 3561 3562 3563 3564 3565
/**
 * 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;
3566
	struct smack_known *skp = NULL;
3567
	int rc = 0;
E
Etienne Basset 已提交
3568
	struct smk_audit_info ad;
3569
#ifdef CONFIG_AUDIT
3570
	struct lsm_network_audit net;
3571
#endif
3572 3573 3574 3575 3576
#if IS_ENABLED(CONFIG_IPV6)
	struct sockaddr_in6 sadd;
	int proto;
#endif /* CONFIG_IPV6 */

3577 3578
	switch (sk->sk_family) {
	case PF_INET:
3579 3580 3581 3582 3583 3584 3585 3586 3587 3588 3589
#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 */
3590 3591 3592 3593
		/*
		 * Translate what netlabel gave us.
		 */
		netlbl_secattr_init(&secattr);
3594

3595 3596
		rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr);
		if (rc == 0)
3597
			skp = smack_from_secattr(&secattr, ssp);
3598
		else
3599
			skp = smack_net_ambient;
3600

3601
		netlbl_secattr_destroy(&secattr);
3602

3603 3604 3605
#ifdef CONFIG_SECURITY_SMACK_NETFILTER
access_check:
#endif
E
Etienne Basset 已提交
3606
#ifdef CONFIG_AUDIT
3607 3608 3609 3610
		smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
		ad.a.u.net->family = sk->sk_family;
		ad.a.u.net->netif = skb->skb_iif;
		ipv4_skb_to_auditdata(skb, &ad.a, NULL);
E
Etienne Basset 已提交
3611
#endif
3612 3613 3614 3615 3616 3617
		/*
		 * 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.
		 */
3618 3619
		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
3620
					MAY_WRITE, rc);
3621 3622 3623
		if (rc != 0)
			netlbl_skbuff_err(skb, rc, 0);
		break;
3624
#if IS_ENABLED(CONFIG_IPV6)
3625
	case PF_INET6:
3626 3627 3628 3629 3630 3631
		proto = smk_skb_to_addr_ipv6(skb, &sadd);
		if (proto != IPPROTO_UDP && proto != IPPROTO_TCP)
			break;
#ifdef CONFIG_SECURITY_SMACK_NETFILTER
		if (skb && skb->secmark != 0)
			skp = smack_from_secid(skb->secmark);
3632
		else
3633 3634 3635 3636 3637 3638 3639 3640 3641 3642 3643 3644 3645
			skp = smack_net_ambient;
#ifdef CONFIG_AUDIT
		smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
		ad.a.u.net->family = sk->sk_family;
		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);
#else /* CONFIG_SECURITY_SMACK_NETFILTER */
		rc = smk_ipv6_port_check(sk, &sadd, SMK_RECEIVING);
#endif /* CONFIG_SECURITY_SMACK_NETFILTER */
3646
		break;
3647
#endif /* CONFIG_IPV6 */
3648
	}
3649

3650
	return rc;
3651 3652 3653 3654 3655 3656 3657
}

/**
 * smack_socket_getpeersec_stream - pull in packet label
 * @sock: the socket
 * @optval: user's destination
 * @optlen: size thereof
3658
 * @len: max thereof
3659 3660 3661 3662 3663 3664 3665 3666
 *
 * 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;
3667 3668
	char *rcp = "";
	int slen = 1;
3669 3670 3671
	int rc = 0;

	ssp = sock->sk->sk_security;
3672
	if (ssp->smk_packet != NULL) {
3673
		rcp = ssp->smk_packet->smk_known;
3674 3675
		slen = strlen(rcp) + 1;
	}
3676 3677 3678

	if (slen > len)
		rc = -ERANGE;
3679
	else if (copy_to_user(optval, rcp, slen) != 0)
3680 3681 3682 3683 3684 3685 3686 3687 3688 3689 3690
		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
3691
 * @sock: the peer socket
3692 3693 3694 3695 3696 3697 3698 3699 3700 3701
 * @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;
3702
	struct socket_smack *ssp = NULL;
3703
	struct smack_known *skp;
C
Casey Schaufler 已提交
3704 3705
	int family = PF_UNSPEC;
	u32 s = 0;	/* 0 is the invalid secid */
3706 3707
	int rc;

C
Casey Schaufler 已提交
3708 3709 3710
	if (skb != NULL) {
		if (skb->protocol == htons(ETH_P_IP))
			family = PF_INET;
3711
#if IS_ENABLED(CONFIG_IPV6)
C
Casey Schaufler 已提交
3712 3713
		else if (skb->protocol == htons(ETH_P_IPV6))
			family = PF_INET6;
3714
#endif /* CONFIG_IPV6 */
3715
	}
C
Casey Schaufler 已提交
3716 3717
	if (family == PF_UNSPEC && sock != NULL)
		family = sock->sk->sk_family;
3718

3719 3720
	switch (family) {
	case PF_UNIX:
3721
		ssp = sock->sk->sk_security;
3722
		s = ssp->smk_out->smk_secid;
3723 3724 3725 3726 3727 3728 3729
		break;
	case PF_INET:
#ifdef CONFIG_SECURITY_SMACK_NETFILTER
		s = skb->secmark;
		if (s != 0)
			break;
#endif
C
Casey Schaufler 已提交
3730 3731 3732
		/*
		 * Translate what netlabel gave us.
		 */
3733 3734
		if (sock != NULL && sock->sk != NULL)
			ssp = sock->sk->sk_security;
C
Casey Schaufler 已提交
3735 3736 3737
		netlbl_secattr_init(&secattr);
		rc = netlbl_skbuff_getattr(skb, family, &secattr);
		if (rc == 0) {
3738 3739
			skp = smack_from_secattr(&secattr, ssp);
			s = skp->smk_secid;
C
Casey Schaufler 已提交
3740 3741
		}
		netlbl_secattr_destroy(&secattr);
3742 3743 3744 3745 3746 3747 3748 3749
		break;
#if IS_ENABLED(CONFIG_IPV6)
	case PF_INET6:
#ifdef CONFIG_SECURITY_SMACK_NETFILTER
		s = skb->secmark;
#endif /* CONFIG_SECURITY_SMACK_NETFILTER */
		break;
#endif /* CONFIG_IPV6 */
C
Casey Schaufler 已提交
3750 3751
	}
	*secid = s;
3752 3753 3754 3755 3756 3757
	if (s == 0)
		return -EINVAL;
	return 0;
}

/**
3758 3759 3760
 * smack_sock_graft - Initialize a newly created socket with an existing sock
 * @sk: child sock
 * @parent: parent socket
3761
 *
3762 3763
 * Set the smk_{in,out} state of an existing sock based on the process that
 * is creating the new socket.
3764 3765 3766 3767
 */
static void smack_sock_graft(struct sock *sk, struct socket *parent)
{
	struct socket_smack *ssp;
3768
	struct smack_known *skp = smk_of_current();
3769

3770 3771
	if (sk == NULL ||
	    (sk->sk_family != PF_INET && sk->sk_family != PF_INET6))
3772 3773 3774
		return;

	ssp = sk->sk_security;
3775
	ssp->smk_in = skp;
3776
	ssp->smk_out = skp;
3777
	/* cssp->smk_packet is already set in smack_inet_csk_clone() */
3778 3779 3780 3781 3782 3783 3784 3785 3786 3787 3788 3789 3790 3791
}

/**
 * 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)
{
3792
	u16 family = sk->sk_family;
3793
	struct smack_known *skp;
3794
	struct socket_smack *ssp = sk->sk_security;
3795 3796 3797
	struct netlbl_lsm_secattr secattr;
	struct sockaddr_in addr;
	struct iphdr *hdr;
3798
	struct smack_known *hskp;
3799
	int rc;
E
Etienne Basset 已提交
3800
	struct smk_audit_info ad;
3801
#ifdef CONFIG_AUDIT
3802
	struct lsm_network_audit net;
3803
#endif
3804

3805
#if IS_ENABLED(CONFIG_IPV6)
3806 3807 3808 3809 3810 3811 3812 3813 3814 3815 3816
	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;
	}
3817
#endif /* CONFIG_IPV6 */
3818

3819 3820
	netlbl_secattr_init(&secattr);
	rc = netlbl_skbuff_getattr(skb, family, &secattr);
3821
	if (rc == 0)
3822
		skp = smack_from_secattr(&secattr, ssp);
3823
	else
3824
		skp = &smack_known_huh;
3825 3826
	netlbl_secattr_destroy(&secattr);

E
Etienne Basset 已提交
3827
#ifdef CONFIG_AUDIT
3828 3829 3830
	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
3831 3832
	ipv4_skb_to_auditdata(skb, &ad.a, NULL);
#endif
3833
	/*
3834 3835
	 * Receiving a packet requires that the other end be able to write
	 * here. Read access is not required.
3836
	 */
3837 3838
	rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad);
	rc = smk_bu_note("IPv4 connect", skp, ssp->smk_in, MAY_WRITE, rc);
3839 3840 3841 3842 3843 3844 3845
	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.
	 */
3846
	req->peer_secid = skp->smk_secid;
3847 3848 3849 3850

	/*
	 * 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
3851
	 * propagate the wire-label to the sock when it is created.
3852 3853 3854 3855
	 */
	hdr = ip_hdr(skb);
	addr.sin_addr.s_addr = hdr->saddr;
	rcu_read_lock();
3856
	hskp = smack_host_label(&addr);
3857 3858
	rcu_read_unlock();

3859
	if (hskp == NULL)
3860
		rc = netlbl_req_setattr(req, &skp->smk_netlabel);
3861
	else
3862
		netlbl_req_delattr(req);
3863 3864 3865 3866

	return rc;
}

3867 3868 3869 3870 3871 3872 3873 3874 3875 3876 3877
/**
 * 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;
3878
	struct smack_known *skp;
3879

3880 3881
	if (req->peer_secid != 0) {
		skp = smack_from_secid(req->peer_secid);
3882
		ssp->smk_packet = skp;
3883
	} else
3884
		ssp->smk_packet = NULL;
3885 3886
}

3887 3888 3889 3890 3891 3892 3893 3894 3895 3896 3897 3898
/*
 * 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
3899
 * @cred: the credentials to use
3900 3901 3902 3903 3904 3905
 * @flags: unused
 *
 * No allocation required
 *
 * Returns 0
 */
D
David Howells 已提交
3906
static int smack_key_alloc(struct key *key, const struct cred *cred,
3907 3908
			   unsigned long flags)
{
3909 3910
	struct smack_known *skp = smk_of_task(cred->security);

3911
	key->security = skp;
3912 3913 3914 3915 3916 3917 3918 3919 3920 3921 3922 3923 3924 3925
	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;
}

3926
/**
3927 3928
 * smack_key_permission - Smack access on a key
 * @key_ref: gets to the object
D
David Howells 已提交
3929
 * @cred: the credentials to use
3930
 * @perm: requested key permissions
3931 3932 3933 3934 3935
 *
 * 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,
3936
				const struct cred *cred, unsigned perm)
3937 3938
{
	struct key *keyp;
E
Etienne Basset 已提交
3939
	struct smk_audit_info ad;
3940
	struct smack_known *tkp = smk_of_task(cred->security);
3941
	int request = 0;
C
Casey Schaufler 已提交
3942
	int rc;
3943 3944 3945 3946 3947 3948 3949 3950 3951 3952 3953 3954 3955

	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
	 */
3956
	if (tkp == NULL)
3957
		return -EACCES;
E
Etienne Basset 已提交
3958 3959 3960 3961 3962
#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
3963 3964 3965 3966
	if (perm & KEY_NEED_READ)
		request = MAY_READ;
	if (perm & (KEY_NEED_WRITE | KEY_NEED_LINK | KEY_NEED_SETATTR))
		request = MAY_WRITE;
C
Casey Schaufler 已提交
3967 3968 3969
	rc = smk_access(tkp, keyp->security, request, &ad);
	rc = smk_bu_note("key access", tkp, keyp->security, request, rc);
	return rc;
3970 3971 3972
}
#endif /* CONFIG_KEYS */

3973 3974 3975 3976 3977 3978 3979 3980 3981 3982 3983 3984 3985 3986 3987 3988 3989 3990 3991 3992 3993 3994 3995 3996 3997 3998 3999
/*
 * 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)
{
4000
	struct smack_known *skp;
4001 4002 4003 4004 4005 4006
	char **rule = (char **)vrule;
	*rule = NULL;

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

4007
	if (op != Audit_equal && op != Audit_not_equal)
4008 4009
		return -EINVAL;

4010 4011 4012
	skp = smk_import_entry(rulestr, 0);
	if (skp)
		*rule = skp->smk_known;
4013 4014 4015 4016 4017 4018 4019 4020 4021 4022 4023 4024 4025 4026 4027 4028 4029 4030 4031 4032 4033 4034 4035 4036 4037 4038 4039 4040 4041 4042 4043 4044 4045 4046 4047 4048 4049 4050 4051 4052 4053

	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
 * @actx: audit context associated with the check
 *
 * The core Audit hook. It's used to take the decision of
 * whether to audit or not to audit a given object.
 */
static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule,
				  struct audit_context *actx)
{
4054
	struct smack_known *skp;
4055 4056
	char *rule = vrule;

4057 4058
	if (unlikely(!rule)) {
		WARN_ONCE(1, "Smack: missing rule\n");
4059 4060 4061 4062 4063 4064
		return -ENOENT;
	}

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

4065
	skp = smack_from_secid(secid);
4066 4067 4068 4069 4070 4071

	/*
	 * No need to do string comparisons. If a match occurs,
	 * both pointers will point to the same smack_known
	 * label.
	 */
4072
	if (op == Audit_equal)
4073
		return (rule == skp->smk_known);
4074
	if (op == Audit_not_equal)
4075
		return (rule != skp->smk_known);
4076 4077 4078 4079 4080 4081 4082 4083 4084 4085 4086 4087 4088 4089 4090 4091 4092

	return 0;
}

/**
 * smack_audit_rule_free - free smack rule representation
 * @vrule: rule to be freed.
 *
 * No memory was allocated.
 */
static void smack_audit_rule_free(void *vrule)
{
	/* No-op */
}

#endif /* CONFIG_AUDIT */

4093 4094 4095 4096 4097 4098 4099 4100 4101 4102
/**
 * 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);
}


4103
/**
4104 4105 4106 4107 4108 4109 4110 4111 4112
 * 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)
{
4113
	struct smack_known *skp = smack_from_secid(secid);
4114

4115
	if (secdata)
4116 4117
		*secdata = skp->smk_known;
	*seclen = strlen(skp->smk_known);
4118 4119 4120
	return 0;
}

4121
/**
4122 4123 4124 4125 4126 4127 4128
 * 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.
 */
4129
static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
4130
{
4131 4132 4133 4134 4135 4136
	struct smack_known *skp = smk_find_entry(secdata);

	if (skp)
		*secid = skp->smk_secid;
	else
		*secid = 0;
4137 4138 4139
	return 0;
}

4140
/**
4141
 * smack_release_secctx - don't do anything.
4142 4143
 * @secdata: unused
 * @seclen: unused
4144 4145 4146 4147 4148 4149 4150
 *
 * Exists to make sure nothing gets done, and properly
 */
static void smack_release_secctx(char *secdata, u32 seclen)
{
}

4151 4152 4153 4154 4155 4156 4157 4158 4159 4160 4161 4162 4163 4164 4165 4166 4167 4168 4169 4170 4171
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)
{
	int len = 0;
	len = smack_inode_getsecurity(inode, XATTR_SMACK_SUFFIX, ctx, true);

	if (len < 0)
		return len;
	*ctxlen = len;
	return 0;
}

4172 4173 4174
struct security_operations smack_ops = {
	.name =				"smack",

4175
	.ptrace_access_check =		smack_ptrace_access_check,
4176
	.ptrace_traceme =		smack_ptrace_traceme,
4177 4178 4179 4180 4181 4182 4183 4184
	.syslog = 			smack_syslog,

	.sb_alloc_security = 		smack_sb_alloc_security,
	.sb_free_security = 		smack_sb_free_security,
	.sb_copy_data = 		smack_sb_copy_data,
	.sb_kern_mount = 		smack_sb_kern_mount,
	.sb_statfs = 			smack_sb_statfs,

4185
	.bprm_set_creds =		smack_bprm_set_creds,
4186 4187
	.bprm_committing_creds =	smack_bprm_committing_creds,
	.bprm_secureexec =		smack_bprm_secureexec,
4188

4189 4190 4191 4192 4193 4194 4195 4196 4197 4198 4199 4200 4201 4202 4203 4204 4205
	.inode_alloc_security = 	smack_inode_alloc_security,
	.inode_free_security = 		smack_inode_free_security,
	.inode_init_security = 		smack_inode_init_security,
	.inode_link = 			smack_inode_link,
	.inode_unlink = 		smack_inode_unlink,
	.inode_rmdir = 			smack_inode_rmdir,
	.inode_rename = 		smack_inode_rename,
	.inode_permission = 		smack_inode_permission,
	.inode_setattr = 		smack_inode_setattr,
	.inode_getattr = 		smack_inode_getattr,
	.inode_setxattr = 		smack_inode_setxattr,
	.inode_post_setxattr = 		smack_inode_post_setxattr,
	.inode_getxattr = 		smack_inode_getxattr,
	.inode_removexattr = 		smack_inode_removexattr,
	.inode_getsecurity = 		smack_inode_getsecurity,
	.inode_setsecurity = 		smack_inode_setsecurity,
	.inode_listsecurity = 		smack_inode_listsecurity,
4206
	.inode_getsecid =		smack_inode_getsecid,
4207 4208 4209 4210 4211 4212 4213

	.file_permission = 		smack_file_permission,
	.file_alloc_security = 		smack_file_alloc_security,
	.file_free_security = 		smack_file_free_security,
	.file_ioctl = 			smack_file_ioctl,
	.file_lock = 			smack_file_lock,
	.file_fcntl = 			smack_file_fcntl,
4214 4215
	.mmap_file =			smack_mmap_file,
	.mmap_addr =			cap_mmap_addr,
4216 4217 4218 4219
	.file_set_fowner = 		smack_file_set_fowner,
	.file_send_sigiotask = 		smack_file_send_sigiotask,
	.file_receive = 		smack_file_receive,

4220
	.file_open =			smack_file_open,
4221

4222
	.cred_alloc_blank =		smack_cred_alloc_blank,
4223
	.cred_free =			smack_cred_free,
D
David Howells 已提交
4224
	.cred_prepare =			smack_cred_prepare,
4225
	.cred_transfer =		smack_cred_transfer,
4226 4227
	.kernel_act_as =		smack_kernel_act_as,
	.kernel_create_files_as =	smack_kernel_create_files_as,
4228 4229 4230 4231 4232 4233 4234 4235 4236 4237 4238 4239 4240 4241 4242
	.task_setpgid = 		smack_task_setpgid,
	.task_getpgid = 		smack_task_getpgid,
	.task_getsid = 			smack_task_getsid,
	.task_getsecid = 		smack_task_getsecid,
	.task_setnice = 		smack_task_setnice,
	.task_setioprio = 		smack_task_setioprio,
	.task_getioprio = 		smack_task_getioprio,
	.task_setscheduler = 		smack_task_setscheduler,
	.task_getscheduler = 		smack_task_getscheduler,
	.task_movememory = 		smack_task_movememory,
	.task_kill = 			smack_task_kill,
	.task_wait = 			smack_task_wait,
	.task_to_inode = 		smack_task_to_inode,

	.ipc_permission = 		smack_ipc_permission,
4243
	.ipc_getsecid =			smack_ipc_getsecid,
4244 4245 4246 4247 4248 4249 4250 4251 4252 4253 4254 4255 4256 4257 4258 4259 4260 4261 4262 4263 4264 4265 4266 4267 4268 4269 4270 4271 4272 4273 4274 4275

	.msg_msg_alloc_security = 	smack_msg_msg_alloc_security,
	.msg_msg_free_security = 	smack_msg_msg_free_security,

	.msg_queue_alloc_security = 	smack_msg_queue_alloc_security,
	.msg_queue_free_security = 	smack_msg_queue_free_security,
	.msg_queue_associate = 		smack_msg_queue_associate,
	.msg_queue_msgctl = 		smack_msg_queue_msgctl,
	.msg_queue_msgsnd = 		smack_msg_queue_msgsnd,
	.msg_queue_msgrcv = 		smack_msg_queue_msgrcv,

	.shm_alloc_security = 		smack_shm_alloc_security,
	.shm_free_security = 		smack_shm_free_security,
	.shm_associate = 		smack_shm_associate,
	.shm_shmctl = 			smack_shm_shmctl,
	.shm_shmat = 			smack_shm_shmat,

	.sem_alloc_security = 		smack_sem_alloc_security,
	.sem_free_security = 		smack_sem_free_security,
	.sem_associate = 		smack_sem_associate,
	.sem_semctl = 			smack_sem_semctl,
	.sem_semop = 			smack_sem_semop,

	.d_instantiate = 		smack_d_instantiate,

	.getprocattr = 			smack_getprocattr,
	.setprocattr = 			smack_setprocattr,

	.unix_stream_connect = 		smack_unix_stream_connect,
	.unix_may_send = 		smack_unix_may_send,

	.socket_post_create = 		smack_socket_post_create,
4276
#ifndef CONFIG_SECURITY_SMACK_NETFILTER
4277
	.socket_bind =			smack_socket_bind,
4278
#endif /* CONFIG_SECURITY_SMACK_NETFILTER */
4279 4280
	.socket_connect =		smack_socket_connect,
	.socket_sendmsg =		smack_socket_sendmsg,
4281 4282 4283 4284 4285 4286 4287
	.socket_sock_rcv_skb = 		smack_socket_sock_rcv_skb,
	.socket_getpeersec_stream =	smack_socket_getpeersec_stream,
	.socket_getpeersec_dgram =	smack_socket_getpeersec_dgram,
	.sk_alloc_security = 		smack_sk_alloc_security,
	.sk_free_security = 		smack_sk_free_security,
	.sock_graft = 			smack_sock_graft,
	.inet_conn_request = 		smack_inet_conn_request,
4288
	.inet_csk_clone =		smack_inet_csk_clone,
4289

4290 4291 4292 4293 4294 4295
 /* key management security hooks */
#ifdef CONFIG_KEYS
	.key_alloc = 			smack_key_alloc,
	.key_free = 			smack_key_free,
	.key_permission = 		smack_key_permission,
#endif /* CONFIG_KEYS */
4296 4297 4298 4299 4300 4301 4302 4303 4304

 /* Audit hooks */
#ifdef CONFIG_AUDIT
	.audit_rule_init =		smack_audit_rule_init,
	.audit_rule_known =		smack_audit_rule_known,
	.audit_rule_match =		smack_audit_rule_match,
	.audit_rule_free =		smack_audit_rule_free,
#endif /* CONFIG_AUDIT */

4305
	.ismaclabel =			smack_ismaclabel,
4306
	.secid_to_secctx = 		smack_secid_to_secctx,
4307
	.secctx_to_secid = 		smack_secctx_to_secid,
4308
	.release_secctx = 		smack_release_secctx,
4309 4310 4311
	.inode_notifysecctx =		smack_inode_notifysecctx,
	.inode_setsecctx =		smack_inode_setsecctx,
	.inode_getsecctx =		smack_inode_getsecctx,
4312 4313
};

4314

4315
static __init void init_smack_known_list(void)
4316
{
4317 4318 4319 4320 4321 4322 4323 4324 4325 4326 4327 4328 4329 4330 4331 4332 4333 4334 4335 4336 4337
	/*
	 * 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_invalid.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_invalid.smk_rules);
	INIT_LIST_HEAD(&smack_known_web.smk_rules);
	/*
	 * Create the known labels list
	 */
4338 4339 4340 4341 4342 4343
	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_invalid);
	smk_insert_entry(&smack_known_web);
4344 4345
}

4346 4347 4348 4349 4350 4351 4352
/**
 * smack_init - initialize the smack system
 *
 * Returns 0
 */
static __init int smack_init(void)
{
D
David Howells 已提交
4353
	struct cred *cred;
4354
	struct task_smack *tsp;
D
David Howells 已提交
4355

4356 4357 4358
	if (!security_module_enable(&smack_ops))
		return 0;

4359 4360
	smack_enabled = 1;

4361 4362 4363 4364
	smack_inode_cache = KMEM_CACHE(inode_smack, 0);
	if (!smack_inode_cache)
		return -ENOMEM;

4365 4366
	tsp = new_task_smack(&smack_known_floor, &smack_known_floor,
				GFP_KERNEL);
4367 4368
	if (tsp == NULL) {
		kmem_cache_destroy(smack_inode_cache);
4369
		return -ENOMEM;
4370
	}
4371

4372 4373 4374 4375 4376
	printk(KERN_INFO "Smack:  Initializing.\n");

	/*
	 * Set the security state for the initial task.
	 */
D
David Howells 已提交
4377
	cred = (struct cred *) current->cred;
4378
	cred->security = tsp;
4379

4380 4381
	/* initialize the smack_known_list */
	init_smack_known_list();
4382 4383 4384 4385 4386 4387 4388 4389 4390 4391 4392 4393 4394 4395 4396

	/*
	 * Register with LSM
	 */
	if (register_security(&smack_ops))
		panic("smack: Unable to register with kernel.\n");

	return 0;
}

/*
 * Smack requires early initialization in order to label
 * all processes and objects when they are created.
 */
security_initcall(smack_init);