ima_main.c 20.6 KB
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// SPDX-License-Identifier: GPL-2.0-only
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/*
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 * Integrity Measurement Architecture
 *
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 * Copyright (C) 2005,2006,2007,2008 IBM Corporation
 *
 * Authors:
 * Reiner Sailer <sailer@watson.ibm.com>
 * Serge Hallyn <serue@us.ibm.com>
 * Kylene Hall <kylene@us.ibm.com>
 * Mimi Zohar <zohar@us.ibm.com>
 *
 * File: ima_main.c
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 *	implements the IMA hooks: ima_bprm_check, ima_file_mmap,
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 *	and ima_file_check.
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 */
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

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#include <linux/module.h>
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#include <linux/file.h>
#include <linux/binfmts.h>
#include <linux/mount.h>
#include <linux/mman.h>
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#include <linux/slab.h>
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#include <linux/xattr.h>
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#include <linux/ima.h>
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#include <linux/iversion.h>
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#include <linux/fs.h>
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#include "ima.h"

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#ifdef CONFIG_IMA_APPRAISE
int ima_appraise = IMA_APPRAISE_ENFORCE;
#else
int ima_appraise;
#endif

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int ima_hash_algo = HASH_ALGO_SHA1;
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static int hash_setup_done;
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static struct notifier_block ima_lsm_policy_notifier = {
	.notifier_call = ima_lsm_policy_change,
};

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static int __init hash_setup(char *str)
{
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	struct ima_template_desc *template_desc = ima_template_desc_current();
	int i;

	if (hash_setup_done)
		return 1;

	if (strcmp(template_desc->name, IMA_TEMPLATE_IMA_NAME) == 0) {
		if (strncmp(str, "sha1", 4) == 0)
			ima_hash_algo = HASH_ALGO_SHA1;
		else if (strncmp(str, "md5", 3) == 0)
			ima_hash_algo = HASH_ALGO_MD5;
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		else
			return 1;
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		goto out;
	}

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	i = match_string(hash_algo_name, HASH_ALGO__LAST, str);
	if (i < 0)
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		return 1;
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	ima_hash_algo = i;
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out:
	hash_setup_done = 1;
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	return 1;
}
__setup("ima_hash=", hash_setup);

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/* Prevent mmap'ing a file execute that is already mmap'ed write */
static int mmap_violation_check(enum ima_hooks func, struct file *file,
				char **pathbuf, const char **pathname,
				char *filename)
{
	struct inode *inode;
	int rc = 0;

	if ((func == MMAP_CHECK) && mapping_writably_mapped(file->f_mapping)) {
		rc = -ETXTBSY;
		inode = file_inode(file);

		if (!*pathbuf)	/* ima_rdwr_violation possibly pre-fetched */
			*pathname = ima_d_path(&file->f_path, pathbuf,
					       filename);
		integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, *pathname,
				    "mmap_file", "mmapped_writers", rc, 0);
	}
	return rc;
}

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/*
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 * ima_rdwr_violation_check
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 *
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 * Only invalidate the PCR for measured files:
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 *	- Opening a file for write when already open for read,
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 *	  results in a time of measure, time of use (ToMToU) error.
 *	- Opening a file for read when already open for write,
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 *	  could result in a file measurement error.
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 *
 */
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static void ima_rdwr_violation_check(struct file *file,
				     struct integrity_iint_cache *iint,
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				     int must_measure,
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				     char **pathbuf,
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				     const char **pathname,
				     char *filename)
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{
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	struct inode *inode = file_inode(file);
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	fmode_t mode = file->f_mode;
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	bool send_tomtou = false, send_writers = false;
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	if (mode & FMODE_WRITE) {
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		if (atomic_read(&inode->i_readcount) && IS_IMA(inode)) {
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			if (!iint)
				iint = integrity_iint_find(inode);
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			/* IMA_MEASURE is set from reader side */
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			if (iint && test_bit(IMA_MUST_MEASURE,
						&iint->atomic_flags))
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				send_tomtou = true;
		}
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	} else {
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		if (must_measure)
			set_bit(IMA_MUST_MEASURE, &iint->atomic_flags);
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		if (inode_is_open_for_write(inode) && must_measure)
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			send_writers = true;
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	}
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	if (!send_tomtou && !send_writers)
		return;

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	*pathname = ima_d_path(&file->f_path, pathbuf, filename);
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	if (send_tomtou)
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		ima_add_violation(file, *pathname, iint,
				  "invalid_pcr", "ToMToU");
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	if (send_writers)
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		ima_add_violation(file, *pathname, iint,
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				  "invalid_pcr", "open_writers");
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}

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static void ima_check_last_writer(struct integrity_iint_cache *iint,
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				  struct inode *inode, struct file *file)
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{
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	fmode_t mode = file->f_mode;
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	bool update;
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	if (!(mode & FMODE_WRITE))
		return;

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	mutex_lock(&iint->mutex);
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	if (atomic_read(&inode->i_writecount) == 1) {
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		update = test_and_clear_bit(IMA_UPDATE_XATTR,
					    &iint->atomic_flags);
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		if (!IS_I_VERSION(inode) ||
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		    !inode_eq_iversion(inode, iint->version) ||
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		    (iint->flags & IMA_NEW_FILE)) {
			iint->flags &= ~(IMA_DONE_MASK | IMA_NEW_FILE);
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			iint->measured_pcrs = 0;
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			if (update)
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				ima_update_xattr(iint, file);
		}
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	}
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	mutex_unlock(&iint->mutex);
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}

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/**
 * ima_file_free - called on __fput()
 * @file: pointer to file structure being freed
 *
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 * Flag files that changed, based on i_version
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 */
void ima_file_free(struct file *file)
{
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	struct inode *inode = file_inode(file);
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	struct integrity_iint_cache *iint;
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	if (!ima_policy_flag || !S_ISREG(inode->i_mode))
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		return;
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	iint = integrity_iint_find(inode);
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	if (!iint)
		return;
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	ima_check_last_writer(iint, inode, file);
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}

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static int process_measurement(struct file *file, const struct cred *cred,
			       u32 secid, char *buf, loff_t size, int mask,
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			       enum ima_hooks func)
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{
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	struct inode *inode = file_inode(file);
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	struct integrity_iint_cache *iint = NULL;
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	struct ima_template_desc *template_desc = NULL;
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	char *pathbuf = NULL;
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	char filename[NAME_MAX];
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	const char *pathname = NULL;
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	int rc = 0, action, must_appraise = 0;
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	int pcr = CONFIG_IMA_MEASURE_PCR_IDX;
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	struct evm_ima_xattr_data *xattr_value = NULL;
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	struct modsig *modsig = NULL;
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	int xattr_len = 0;
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	bool violation_check;
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	enum hash_algo hash_algo;
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	if (!ima_policy_flag || !S_ISREG(inode->i_mode))
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		return 0;
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	/* Return an IMA_MEASURE, IMA_APPRAISE, IMA_AUDIT action
	 * bitmask based on the appraise/audit/measurement policy.
	 * Included is the appraise submask.
	 */
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	action = ima_get_action(inode, cred, secid, mask, func, &pcr,
				&template_desc);
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	violation_check = ((func == FILE_CHECK || func == MMAP_CHECK) &&
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			   (ima_policy_flag & IMA_MEASURE));
	if (!action && !violation_check)
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		return 0;

	must_appraise = action & IMA_APPRAISE;
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	/*  Is the appraise rule hook specific?  */
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	if (action & IMA_FILE_APPRAISE)
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		func = FILE_CHECK;
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	inode_lock(inode);
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	if (action) {
		iint = integrity_inode_get(inode);
		if (!iint)
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			rc = -ENOMEM;
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	}

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	if (!rc && violation_check)
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		ima_rdwr_violation_check(file, iint, action & IMA_MEASURE,
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					 &pathbuf, &pathname, filename);
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	inode_unlock(inode);

	if (rc)
		goto out;
	if (!action)
		goto out;

	mutex_lock(&iint->mutex);

	if (test_and_clear_bit(IMA_CHANGE_ATTR, &iint->atomic_flags))
		/* reset appraisal flags if ima_inode_post_setattr was called */
		iint->flags &= ~(IMA_APPRAISE | IMA_APPRAISED |
				 IMA_APPRAISE_SUBMASK | IMA_APPRAISED_SUBMASK |
				 IMA_ACTION_FLAGS);

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	/*
	 * Re-evaulate the file if either the xattr has changed or the
	 * kernel has no way of detecting file change on the filesystem.
	 * (Limited to privileged mounted filesystems.)
	 */
	if (test_and_clear_bit(IMA_CHANGE_XATTR, &iint->atomic_flags) ||
	    ((inode->i_sb->s_iflags & SB_I_IMA_UNVERIFIABLE_SIGNATURE) &&
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	     !(inode->i_sb->s_iflags & SB_I_UNTRUSTED_MOUNTER) &&
	     !(action & IMA_FAIL_UNVERIFIABLE_SIGS))) {
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		iint->flags &= ~IMA_DONE_MASK;
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		iint->measured_pcrs = 0;
	}
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	/* Determine if already appraised/measured based on bitmask
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	 * (IMA_MEASURE, IMA_MEASURED, IMA_XXXX_APPRAISE, IMA_XXXX_APPRAISED,
	 *  IMA_AUDIT, IMA_AUDITED)
	 */
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	iint->flags |= action;
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	action &= IMA_DO_MASK;
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	action &= ~((iint->flags & (IMA_DONE_MASK ^ IMA_MEASURED)) >> 1);

	/* If target pcr is already measured, unset IMA_MEASURE action */
	if ((action & IMA_MEASURE) && (iint->measured_pcrs & (0x1 << pcr)))
		action ^= IMA_MEASURE;
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	/* HASH sets the digital signature and update flags, nothing else */
	if ((action & IMA_HASH) &&
	    !(test_bit(IMA_DIGSIG, &iint->atomic_flags))) {
		xattr_len = ima_read_xattr(file_dentry(file), &xattr_value);
		if ((xattr_value && xattr_len > 2) &&
		    (xattr_value->type == EVM_IMA_XATTR_DIGSIG))
			set_bit(IMA_DIGSIG, &iint->atomic_flags);
		iint->flags |= IMA_HASHED;
		action ^= IMA_HASH;
		set_bit(IMA_UPDATE_XATTR, &iint->atomic_flags);
	}

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	/* Nothing to do, just return existing appraised status */
	if (!action) {
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		if (must_appraise) {
			rc = mmap_violation_check(func, file, &pathbuf,
						  &pathname, filename);
			if (!rc)
				rc = ima_get_cache_status(iint, func);
		}
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		goto out_locked;
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	}
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	if ((action & IMA_APPRAISE_SUBMASK) ||
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	    strcmp(template_desc->name, IMA_TEMPLATE_IMA_NAME) != 0) {
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		/* read 'security.ima' */
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		xattr_len = ima_read_xattr(file_dentry(file), &xattr_value);
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		/*
		 * Read the appended modsig if allowed by the policy, and allow
		 * an additional measurement list entry, if needed, based on the
		 * template format and whether the file was already measured.
		 */
		if (iint->flags & IMA_MODSIG_ALLOWED) {
			rc = ima_read_modsig(func, buf, size, &modsig);

			if (!rc && ima_template_has_modsig(template_desc) &&
			    iint->flags & IMA_MEASURED)
				action |= IMA_MEASURE;
		}
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	}

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	hash_algo = ima_get_hash_algo(xattr_value, xattr_len);

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	rc = ima_collect_measurement(iint, file, buf, size, hash_algo, modsig);
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	if (rc != 0 && rc != -EBADF && rc != -EINVAL)
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		goto out_locked;
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	if (!pathbuf)	/* ima_rdwr_violation possibly pre-fetched */
		pathname = ima_d_path(&file->f_path, &pathbuf, filename);
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	if (action & IMA_MEASURE)
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		ima_store_measurement(iint, file, pathname,
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				      xattr_value, xattr_len, modsig, pcr,
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				      template_desc);
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	if (rc == 0 && (action & IMA_APPRAISE_SUBMASK)) {
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		rc = ima_check_blacklist(iint, modsig, pcr);
		if (rc != -EPERM) {
			inode_lock(inode);
			rc = ima_appraise_measurement(func, iint, file,
						      pathname, xattr_value,
						      xattr_len, modsig);
			inode_unlock(inode);
		}
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		if (!rc)
			rc = mmap_violation_check(func, file, &pathbuf,
						  &pathname, filename);
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	}
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	if (action & IMA_AUDIT)
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		ima_audit_measurement(iint, pathname);
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	if ((file->f_flags & O_DIRECT) && (iint->flags & IMA_PERMIT_DIRECTIO))
		rc = 0;
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out_locked:
	if ((mask & MAY_WRITE) && test_bit(IMA_DIGSIG, &iint->atomic_flags) &&
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	     !(iint->flags & IMA_NEW_FILE))
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		rc = -EACCES;
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	mutex_unlock(&iint->mutex);
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	kfree(xattr_value);
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	ima_free_modsig(modsig);
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out:
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	if (pathbuf)
		__putname(pathbuf);
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	if (must_appraise) {
		if (rc && (ima_appraise & IMA_APPRAISE_ENFORCE))
			return -EACCES;
		if (file->f_mode & FMODE_WRITE)
			set_bit(IMA_UPDATE_XATTR, &iint->atomic_flags);
	}
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	return 0;
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}

/**
 * ima_file_mmap - based on policy, collect/store measurement.
 * @file: pointer to the file to be measured (May be NULL)
 * @prot: contains the protection that will be applied by the kernel.
 *
 * Measure files being mmapped executable based on the ima_must_measure()
 * policy decision.
 *
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 * On success return 0.  On integrity appraisal error, assuming the file
 * is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
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 */
int ima_file_mmap(struct file *file, unsigned long prot)
{
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	u32 secid;

	if (file && (prot & PROT_EXEC)) {
		security_task_getsecid(current, &secid);
		return process_measurement(file, current_cred(), secid, NULL,
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					   0, MAY_EXEC, MMAP_CHECK);
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	}

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	return 0;
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}

/**
 * ima_bprm_check - based on policy, collect/store measurement.
 * @bprm: contains the linux_binprm structure
 *
 * The OS protects against an executable file, already open for write,
 * from being executed in deny_write_access() and an executable file,
 * already open for execute, from being modified in get_write_access().
 * So we can be certain that what we verify and measure here is actually
 * what is being executed.
 *
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 * On success return 0.  On integrity appraisal error, assuming the file
 * is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
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 */
int ima_bprm_check(struct linux_binprm *bprm)
{
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	int ret;
	u32 secid;

	security_task_getsecid(current, &secid);
	ret = process_measurement(bprm->file, current_cred(), secid, NULL, 0,
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				  MAY_EXEC, BPRM_CHECK);
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	if (ret)
		return ret;

	security_cred_getsecid(bprm->cred, &secid);
	return process_measurement(bprm->file, bprm->cred, secid, NULL, 0,
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				   MAY_EXEC, CREDS_CHECK);
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}

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/**
 * ima_path_check - based on policy, collect/store measurement.
 * @file: pointer to the file to be measured
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 * @mask: contains MAY_READ, MAY_WRITE, MAY_EXEC or MAY_APPEND
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 *
 * Measure files based on the ima_must_measure() policy decision.
 *
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 * On success return 0.  On integrity appraisal error, assuming the file
 * is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
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 */
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int ima_file_check(struct file *file, int mask)
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{
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	u32 secid;

	security_task_getsecid(current, &secid);
	return process_measurement(file, current_cred(), secid, NULL, 0,
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				   mask & (MAY_READ | MAY_WRITE | MAY_EXEC |
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					   MAY_APPEND), FILE_CHECK);
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}
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EXPORT_SYMBOL_GPL(ima_file_check);
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/**
 * ima_post_create_tmpfile - mark newly created tmpfile as new
 * @file : newly created tmpfile
 *
 * No measuring, appraising or auditing of newly created tmpfiles is needed.
 * Skip calling process_measurement(), but indicate which newly, created
 * tmpfiles are in policy.
 */
void ima_post_create_tmpfile(struct inode *inode)
{
	struct integrity_iint_cache *iint;
	int must_appraise;

	must_appraise = ima_must_appraise(inode, MAY_ACCESS, FILE_CHECK);
	if (!must_appraise)
		return;

	/* Nothing to do if we can't allocate memory */
	iint = integrity_inode_get(inode);
	if (!iint)
		return;

	/* needed for writing the security xattrs */
	set_bit(IMA_UPDATE_XATTR, &iint->atomic_flags);
	iint->ima_file_status = INTEGRITY_PASS;
}

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/**
 * ima_post_path_mknod - mark as a new inode
 * @dentry: newly created dentry
 *
 * Mark files created via the mknodat syscall as new, so that the
 * file data can be written later.
 */
void ima_post_path_mknod(struct dentry *dentry)
{
	struct integrity_iint_cache *iint;
	struct inode *inode = dentry->d_inode;
	int must_appraise;

	must_appraise = ima_must_appraise(inode, MAY_ACCESS, FILE_CHECK);
	if (!must_appraise)
		return;

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	/* Nothing to do if we can't allocate memory */
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	iint = integrity_inode_get(inode);
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	if (!iint)
		return;

	/* needed for re-opening empty files */
	iint->flags |= IMA_NEW_FILE;
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}

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/**
 * ima_read_file - pre-measure/appraise hook decision based on policy
 * @file: pointer to the file to be measured/appraised/audit
 * @read_id: caller identifier
 *
 * Permit reading a file based on policy. The policy rules are written
 * in terms of the policy identifier.  Appraising the integrity of
 * a file requires a file descriptor.
 *
 * For permission return 0, otherwise return -EACCES.
 */
int ima_read_file(struct file *file, enum kernel_read_file_id read_id)
{
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	/*
	 * READING_FIRMWARE_PREALLOC_BUFFER
	 *
	 * Do devices using pre-allocated memory run the risk of the
	 * firmware being accessible to the device prior to the completion
	 * of IMA's signature verification any more than when using two
	 * buffers?
	 */
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	return 0;
}

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const int read_idmap[READING_MAX_ID] = {
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	[READING_FIRMWARE] = FIRMWARE_CHECK,
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	[READING_FIRMWARE_PREALLOC_BUFFER] = FIRMWARE_CHECK,
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	[READING_MODULE] = MODULE_CHECK,
	[READING_KEXEC_IMAGE] = KEXEC_KERNEL_CHECK,
	[READING_KEXEC_INITRAMFS] = KEXEC_INITRAMFS_CHECK,
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	[READING_POLICY] = POLICY_CHECK
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};

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/**
 * ima_post_read_file - in memory collect/appraise/audit measurement
 * @file: pointer to the file to be measured/appraised/audit
 * @buf: pointer to in memory file contents
 * @size: size of in memory file contents
 * @read_id: caller identifier
 *
 * Measure/appraise/audit in memory file based on policy.  Policy rules
 * are written in terms of a policy identifier.
 *
 * On success return 0.  On integrity appraisal error, assuming the file
 * is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
 */
int ima_post_read_file(struct file *file, void *buf, loff_t size,
		       enum kernel_read_file_id read_id)
{
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	enum ima_hooks func;
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	u32 secid;
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	if (!file && read_id == READING_FIRMWARE) {
		if ((ima_appraise & IMA_APPRAISE_FIRMWARE) &&
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		    (ima_appraise & IMA_APPRAISE_ENFORCE)) {
			pr_err("Prevent firmware loading_store.\n");
557
			return -EACCES;	/* INTEGRITY_UNKNOWN */
558
		}
559 560 561
		return 0;
	}

562 563 564 565
	/* permit signed certs */
	if (!file && read_id == READING_X509_CERTIFICATE)
		return 0;

566 567 568 569 570 571
	if (!file || !buf || size == 0) { /* should never happen */
		if (ima_appraise & IMA_APPRAISE_ENFORCE)
			return -EACCES;
		return 0;
	}

572
	func = read_idmap[read_id] ?: FILE_CHECK;
573 574
	security_task_getsecid(current, &secid);
	return process_measurement(file, current_cred(), secid, buf, size,
575
				   MAY_READ, func);
576 577
}

578 579 580 581 582 583 584 585 586 587 588 589
/**
 * ima_load_data - appraise decision based on policy
 * @id: kernel load data caller identifier
 *
 * Callers of this LSM hook can not measure, appraise, or audit the
 * data provided by userspace.  Enforce policy rules requring a file
 * signature (eg. kexec'ed kernel image).
 *
 * For permission return 0, otherwise return -EACCES.
 */
int ima_load_data(enum kernel_load_data_id id)
{
590
	bool ima_enforce, sig_enforce;
591

592 593
	ima_enforce =
		(ima_appraise & IMA_APPRAISE_ENFORCE) == IMA_APPRAISE_ENFORCE;
594 595 596

	switch (id) {
	case LOADING_KEXEC_IMAGE:
597
		if (IS_ENABLED(CONFIG_KEXEC_SIG)
598 599 600 601 602 603
		    && arch_ima_get_secureboot()) {
			pr_err("impossible to appraise a kernel image without a file descriptor; try using kexec_file_load syscall.\n");
			return -EACCES;
		}

		if (ima_enforce && (ima_appraise & IMA_APPRAISE_KEXEC)) {
604 605 606
			pr_err("impossible to appraise a kernel image without a file descriptor; try using kexec_file_load syscall.\n");
			return -EACCES;	/* INTEGRITY_UNKNOWN */
		}
607 608
		break;
	case LOADING_FIRMWARE:
609
		if (ima_enforce && (ima_appraise & IMA_APPRAISE_FIRMWARE)) {
610 611 612
			pr_err("Prevent firmware sysfs fallback loading.\n");
			return -EACCES;	/* INTEGRITY_UNKNOWN */
		}
613 614 615 616
		break;
	case LOADING_MODULE:
		sig_enforce = is_module_sig_enforced();

617 618
		if (ima_enforce && (!sig_enforce
				    && (ima_appraise & IMA_APPRAISE_MODULES))) {
619 620 621
			pr_err("impossible to appraise a module without a file descriptor. sig_enforce kernel parameter might help\n");
			return -EACCES;	/* INTEGRITY_UNKNOWN */
		}
622 623 624 625 626 627
	default:
		break;
	}
	return 0;
}

628 629 630 631 632
/*
 * process_buffer_measurement - Measure the buffer to ima log.
 * @buf: pointer to the buffer that needs to be added to the log.
 * @size: size of buffer(in bytes).
 * @eventname: event name to be used for the buffer entry.
633 634
 * @func: IMA hook
 * @pcr: pcr to extend the measurement
635 636 637
 *
 * Based on policy, the buffer is measured into the ima log.
 */
638 639 640
void process_buffer_measurement(const void *buf, int size,
				const char *eventname, enum ima_hooks func,
				int pcr)
641 642 643 644 645
{
	int ret = 0;
	struct ima_template_entry *entry = NULL;
	struct integrity_iint_cache iint = {};
	struct ima_event_data event_data = {.iint = &iint,
646 647 648
					    .filename = eventname,
					    .buf = buf,
					    .buf_len = size};
649
	struct ima_template_desc *template = NULL;
650 651 652 653 654 655
	struct {
		struct ima_digest_data hdr;
		char digest[IMA_MAX_DIGEST_SIZE];
	} hash = {};
	int violation = 0;
	int action = 0;
656
	u32 secid;
657

658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687
	/*
	 * Both LSM hooks and auxilary based buffer measurements are
	 * based on policy.  To avoid code duplication, differentiate
	 * between the LSM hooks and auxilary buffer measurements,
	 * retrieving the policy rule information only for the LSM hook
	 * buffer measurements.
	 */
	if (func) {
		security_task_getsecid(current, &secid);
		action = ima_get_action(NULL, current_cred(), secid, 0, func,
					&pcr, &template);
		if (!(action & IMA_MEASURE))
			return;
	}

	if (!pcr)
		pcr = CONFIG_IMA_MEASURE_PCR_IDX;

	if (!template) {
		template = lookup_template_desc("ima-buf");
		ret = template_desc_init_fields(template->fmt,
						&(template->fields),
						&(template->num_fields));
		if (ret < 0) {
			pr_err("template %s init failed, result: %d\n",
			       (strlen(template->name) ?
				template->name : template->fmt), ret);
			return;
		}
	}
688 689 690 691 692 693 694 695 696

	iint.ima_hash = &hash.hdr;
	iint.ima_hash->algo = ima_hash_algo;
	iint.ima_hash->length = hash_digest_size[ima_hash_algo];

	ret = ima_calc_buffer_hash(buf, size, iint.ima_hash);
	if (ret < 0)
		goto out;

697
	ret = ima_alloc_init_template(&event_data, &entry, template);
698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718
	if (ret < 0)
		goto out;

	ret = ima_store_template(entry, violation, NULL, buf, pcr);

	if (ret < 0)
		ima_free_template_entry(entry);

out:
	return;
}

/**
 * ima_kexec_cmdline - measure kexec cmdline boot args
 * @buf: pointer to buffer
 * @size: size of buffer
 *
 * Buffers can only be measured, not appraised.
 */
void ima_kexec_cmdline(const void *buf, int size)
{
719
	if (buf && size != 0)
720
		process_buffer_measurement(buf, size, "kexec-cmdline",
721
					   KEXEC_CMDLINE, 0);
722 723
}

724 725 726 727
static int __init init_ima(void)
{
	int error;

728
	ima_init_template_list();
729
	hash_setup(CONFIG_IMA_DEFAULT_HASH);
730
	error = ima_init();
731 732 733 734 735 736 737 738 739 740

	if (error && strcmp(hash_algo_name[ima_hash_algo],
			    CONFIG_IMA_DEFAULT_HASH) != 0) {
		pr_info("Allocating %s failed, going to use default hash algorithm %s\n",
			hash_algo_name[ima_hash_algo], CONFIG_IMA_DEFAULT_HASH);
		hash_setup_done = 0;
		hash_setup(CONFIG_IMA_DEFAULT_HASH);
		error = ima_init();
	}

741 742 743 744
	error = register_blocking_lsm_notifier(&ima_lsm_policy_notifier);
	if (error)
		pr_warn("Couldn't register LSM notifier, error %d\n", error);

745
	if (!error)
746
		ima_update_policy_flag();
747

748 749 750 751
	return error;
}

late_initcall(init_ima);	/* Start IMA after the TPM is available */