[deliverable/linux.git] / security / integrity / ima / ima_appraise.c

/*
 * Copyright (C) 2011 IBM Corporation
 *
 * Author:
 * Mimi Zohar <zohar@us.ibm.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, version 2 of the License.
 */
#include <linux/module.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/xattr.h>
#include <linux/magic.h>
#include <linux/ima.h>
#include <linux/evm.h>
#include <crypto/hash_info.h>

#include "ima.h"

static int __init default_appraise_setup(char *str)
{
	if (strncmp(str, "off", 3) == 0)
		ima_appraise = 0;
	else if (strncmp(str, "fix", 3) == 0)
		ima_appraise = IMA_APPRAISE_FIX;
	return 1;
}

__setup("ima_appraise=", default_appraise_setup);

/*
 * ima_must_appraise - set appraise flag
 *
 * Return 1 to appraise
 */
int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func)
{
	if (!ima_appraise)
		return 0;

	return ima_match_policy(inode, func, mask, IMA_APPRAISE);
}

static int ima_fix_xattr(struct dentry *dentry,
			 struct integrity_iint_cache *iint)
{
	int rc, offset;
	u8 algo = iint->ima_hash->algo;

	if (algo <= HASH_ALGO_SHA1) {
		offset = 1;
		iint->ima_hash->xattr.sha1.type = IMA_XATTR_DIGEST;
	} else {
		offset = 0;
		iint->ima_hash->xattr.ng.type = IMA_XATTR_DIGEST_NG;
		iint->ima_hash->xattr.ng.algo = algo;
	}
	rc = __vfs_setxattr_noperm(dentry, XATTR_NAME_IMA,
				   &iint->ima_hash->xattr.data[offset],
				   (sizeof(iint->ima_hash->xattr) - offset) +
				   iint->ima_hash->length, 0);
	return rc;
}

/* Return specific func appraised cached result */
enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint,
					   int func)
{
	switch (func) {
	case MMAP_CHECK:
		return iint->ima_mmap_status;
	case BPRM_CHECK:
		return iint->ima_bprm_status;
	case MODULE_CHECK:
		return iint->ima_module_status;
	case FILE_CHECK:
	default:
		return iint->ima_file_status;
	}
}

static void ima_set_cache_status(struct integrity_iint_cache *iint,
				 int func, enum integrity_status status)
{
	switch (func) {
	case MMAP_CHECK:
		iint->ima_mmap_status = status;
		break;
	case BPRM_CHECK:
		iint->ima_bprm_status = status;
		break;
	case MODULE_CHECK:
		iint->ima_module_status = status;
		break;
	case FILE_CHECK:
	default:
		iint->ima_file_status = status;
		break;
	}
}

static void ima_cache_flags(struct integrity_iint_cache *iint, int func)
{
	switch (func) {
	case MMAP_CHECK:
		iint->flags |= (IMA_MMAP_APPRAISED | IMA_APPRAISED);
		break;
	case BPRM_CHECK:
		iint->flags |= (IMA_BPRM_APPRAISED | IMA_APPRAISED);
		break;
	case MODULE_CHECK:
		iint->flags |= (IMA_MODULE_APPRAISED | IMA_APPRAISED);
		break;
	case FILE_CHECK:
	default:
		iint->flags |= (IMA_FILE_APPRAISED | IMA_APPRAISED);
		break;
	}
}

void ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, int xattr_len,
		       struct ima_digest_data *hash)
{
	struct signature_v2_hdr *sig;

	if (!xattr_value || xattr_len < 2)
		return;

	switch (xattr_value->type) {
	case EVM_IMA_XATTR_DIGSIG:
		sig = (typeof(sig))xattr_value;
		if (sig->version != 2 || xattr_len <= sizeof(*sig))
			return;
		hash->algo = sig->hash_algo;
		break;
	case IMA_XATTR_DIGEST_NG:
		hash->algo = xattr_value->digest[0];
		break;
	case IMA_XATTR_DIGEST:
		/* this is for backward compatibility */
		if (xattr_len == 21) {
			unsigned int zero = 0;
			if (!memcmp(&xattr_value->digest[16], &zero, 4))
				hash->algo = HASH_ALGO_MD5;
			else
				hash->algo = HASH_ALGO_SHA1;
		} else if (xattr_len == 17)
			hash->algo = HASH_ALGO_MD5;
		break;
	}
}

int ima_read_xattr(struct dentry *dentry,
		   struct evm_ima_xattr_data **xattr_value)
{
	struct inode *inode = dentry->d_inode;

	if (!inode->i_op->getxattr)
		return 0;

	return vfs_getxattr_alloc(dentry, XATTR_NAME_IMA, (char **)xattr_value,
				  0, GFP_NOFS);
}

/*
 * ima_appraise_measurement - appraise file measurement
 *
 * Call evm_verifyxattr() to verify the integrity of 'security.ima'.
 * Assuming success, compare the xattr hash with the collected measurement.
 *
 * Return 0 on success, error code otherwise
 */
int ima_appraise_measurement(int func, struct integrity_iint_cache *iint,
			     struct file *file, const unsigned char *filename,
			     struct evm_ima_xattr_data *xattr_value,
			     int xattr_len)
{
	static const char op[] = "appraise_data";
	char *cause = "unknown";
	struct dentry *dentry = file->f_dentry;
	struct inode *inode = dentry->d_inode;
	enum integrity_status status = INTEGRITY_UNKNOWN;
	int rc = xattr_len, hash_start = 0;

	if (!ima_appraise)
		return 0;
	if (!inode->i_op->getxattr)
		return INTEGRITY_UNKNOWN;

	if (rc <= 0) {
		if (rc && rc != -ENODATA)
			goto out;

		cause = "missing-hash";
		status =
		    (inode->i_size == 0) ? INTEGRITY_PASS : INTEGRITY_NOLABEL;
		goto out;
	}

	status = evm_verifyxattr(dentry, XATTR_NAME_IMA, xattr_value, rc, iint);
	if ((status != INTEGRITY_PASS) && (status != INTEGRITY_UNKNOWN)) {
		if ((status == INTEGRITY_NOLABEL)
		    || (status == INTEGRITY_NOXATTRS))
			cause = "missing-HMAC";
		else if (status == INTEGRITY_FAIL)
			cause = "invalid-HMAC";
		goto out;
	}
	switch (xattr_value->type) {
	case IMA_XATTR_DIGEST_NG:
		/* first byte contains algorithm id */
		hash_start = 1;
	case IMA_XATTR_DIGEST:
		if (iint->flags & IMA_DIGSIG_REQUIRED) {
			cause = "IMA signature required";
			status = INTEGRITY_FAIL;
			break;
		}
		if (xattr_len - sizeof(xattr_value->type) - hash_start >=
				iint->ima_hash->length)
			/* xattr length may be longer. md5 hash in previous
			   version occupied 20 bytes in xattr, instead of 16
			 */
			rc = memcmp(&xattr_value->digest[hash_start],
				    iint->ima_hash->digest,
				    iint->ima_hash->length);
		else
			rc = -EINVAL;
		if (rc) {
			cause = "invalid-hash";
			status = INTEGRITY_FAIL;
			break;
		}
		status = INTEGRITY_PASS;
		break;
	case EVM_IMA_XATTR_DIGSIG:
		iint->flags |= IMA_DIGSIG;
		rc = integrity_digsig_verify(INTEGRITY_KEYRING_IMA,
					     (const char *)xattr_value, rc,
					     iint->ima_hash->digest,
					     iint->ima_hash->length);
		if (rc == -EOPNOTSUPP) {
			status = INTEGRITY_UNKNOWN;
		} else if (rc) {
			cause = "invalid-signature";
			status = INTEGRITY_FAIL;
		} else {
			status = INTEGRITY_PASS;
		}
		break;
	default:
		status = INTEGRITY_UNKNOWN;
		cause = "unknown-ima-data";
		break;
	}

out:
	if (status != INTEGRITY_PASS) {
		if ((ima_appraise & IMA_APPRAISE_FIX) &&
		    (!xattr_value ||
		     xattr_value->type != EVM_IMA_XATTR_DIGSIG)) {
			if (!ima_fix_xattr(dentry, iint))
				status = INTEGRITY_PASS;
		}
		integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, filename,
				    op, cause, rc, 0);
	} else {
		ima_cache_flags(iint, func);
	}
	ima_set_cache_status(iint, func, status);
	return status;
}

/*
 * ima_update_xattr - update 'security.ima' hash value
 */
void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file)
{
	struct dentry *dentry = file->f_dentry;
	int rc = 0;

	/* do not collect and update hash for digital signatures */
	if (iint->flags & IMA_DIGSIG)
		return;

	rc = ima_collect_measurement(iint, file, NULL, NULL);
	if (rc < 0)
		return;

	ima_fix_xattr(dentry, iint);
}

/**
 * ima_inode_post_setattr - reflect file metadata changes
 * @dentry: pointer to the affected dentry
 *
 * Changes to a dentry's metadata might result in needing to appraise.
 *
 * This function is called from notify_change(), which expects the caller
 * to lock the inode's i_mutex.
 */
void ima_inode_post_setattr(struct dentry *dentry)
{
	struct inode *inode = dentry->d_inode;
	struct integrity_iint_cache *iint;
	int must_appraise, rc;

	if (!ima_initialized || !ima_appraise || !S_ISREG(inode->i_mode)
	    || !inode->i_op->removexattr)
		return;

	must_appraise = ima_must_appraise(inode, MAY_ACCESS, POST_SETATTR);
	iint = integrity_iint_find(inode);
	if (iint) {
		iint->flags &= ~(IMA_APPRAISE | IMA_APPRAISED |
				 IMA_APPRAISE_SUBMASK | IMA_APPRAISED_SUBMASK |
				 IMA_ACTION_FLAGS);
		if (must_appraise)
			iint->flags |= IMA_APPRAISE;
	}
	if (!must_appraise)
		rc = inode->i_op->removexattr(dentry, XATTR_NAME_IMA);
	return;
}

/*
 * ima_protect_xattr - protect 'security.ima'
 *
 * Ensure that not just anyone can modify or remove 'security.ima'.
 */
static int ima_protect_xattr(struct dentry *dentry, const char *xattr_name,
			     const void *xattr_value, size_t xattr_value_len)
{
	if (strcmp(xattr_name, XATTR_NAME_IMA) == 0) {
		if (!capable(CAP_SYS_ADMIN))
			return -EPERM;
		return 1;
	}
	return 0;
}

static void ima_reset_appraise_flags(struct inode *inode)
{
	struct integrity_iint_cache *iint;

	if (!ima_initialized || !ima_appraise || !S_ISREG(inode->i_mode))
		return;

	iint = integrity_iint_find(inode);
	if (!iint)
		return;

	iint->flags &= ~IMA_DONE_MASK;
	return;
}

int ima_inode_setxattr(struct dentry *dentry, const char *xattr_name,
		       const void *xattr_value, size_t xattr_value_len)
{
	int result;

	result = ima_protect_xattr(dentry, xattr_name, xattr_value,
				   xattr_value_len);
	if (result == 1) {
		ima_reset_appraise_flags(dentry->d_inode);
		result = 0;
	}
	return result;
}

int ima_inode_removexattr(struct dentry *dentry, const char *xattr_name)
{
	int result;

	result = ima_protect_xattr(dentry, xattr_name, NULL, 0);
	if (result == 1) {
		ima_reset_appraise_flags(dentry->d_inode);
		result = 0;
	}
	return result;
}
Commit	Line	Data
2fe5d6de MZ	1	/*
	2	* Copyright (C) 2011 IBM Corporation
	3	*
	4	* Author:
	5	* Mimi Zohar <zohar@us.ibm.com>
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License as published by
	9	* the Free Software Foundation, version 2 of the License.
	10	*/
	11	#include <linux/module.h>
	12	#include <linux/file.h>
	13	#include <linux/fs.h>
	14	#include <linux/xattr.h>
	15	#include <linux/magic.h>
	16	#include <linux/ima.h>
	17	#include <linux/evm.h>
3ea7a560	18	#include <crypto/hash_info.h>
2fe5d6de MZ	19
	20	#include "ima.h"
	21
	22	static int __init default_appraise_setup(char *str)
	23	{
	24	if (strncmp(str, "off", 3) == 0)
	25	ima_appraise = 0;
	26	else if (strncmp(str, "fix", 3) == 0)
	27	ima_appraise = IMA_APPRAISE_FIX;
	28	return 1;
	29	}
	30
	31	__setup("ima_appraise=", default_appraise_setup);
	32
	33	/*
	34	* ima_must_appraise - set appraise flag
	35	*
	36	* Return 1 to appraise
	37	*/
d26e1936	38	int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func)
2fe5d6de	39	{
07f6a794 MZ	40	if (!ima_appraise)
	41	return 0;
	42
	43	return ima_match_policy(inode, func, mask, IMA_APPRAISE);
2fe5d6de MZ	44	}
2fe5d6de MZ	45
def3e8b9	46	static int ima_fix_xattr(struct dentry *dentry,
c7c8bb23	47	struct integrity_iint_cache *iint)
2fe5d6de	48	{
3ea7a560 DK	49	int rc, offset;
	50	u8 algo = iint->ima_hash->algo;
	51
	52	if (algo <= HASH_ALGO_SHA1) {
	53	offset = 1;
	54	iint->ima_hash->xattr.sha1.type = IMA_XATTR_DIGEST;
	55	} else {
	56	offset = 0;
	57	iint->ima_hash->xattr.ng.type = IMA_XATTR_DIGEST_NG;
	58	iint->ima_hash->xattr.ng.algo = algo;
	59	}
	60	rc = __vfs_setxattr_noperm(dentry, XATTR_NAME_IMA,
	61	&iint->ima_hash->xattr.data[offset],
	62	(sizeof(iint->ima_hash->xattr) - offset) +
	63	iint->ima_hash->length, 0);
	64	return rc;
2fe5d6de MZ	65	}
2fe5d6de MZ	66
d79d72e0 MZ	67	/* Return specific func appraised cached result */
	68	enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint,
	69	int func)
	70	{
089bc8e9	71	switch (func) {
d79d72e0 MZ	72	case MMAP_CHECK:
	73	return iint->ima_mmap_status;
	74	case BPRM_CHECK:
	75	return iint->ima_bprm_status;
	76	case MODULE_CHECK:
	77	return iint->ima_module_status;
	78	case FILE_CHECK:
	79	default:
	80	return iint->ima_file_status;
	81	}
	82	}
	83
	84	static void ima_set_cache_status(struct integrity_iint_cache *iint,
	85	int func, enum integrity_status status)
	86	{
089bc8e9	87	switch (func) {
d79d72e0 MZ	88	case MMAP_CHECK:
	89	iint->ima_mmap_status = status;
	90	break;
	91	case BPRM_CHECK:
	92	iint->ima_bprm_status = status;
	93	break;
	94	case MODULE_CHECK:
	95	iint->ima_module_status = status;
	96	break;
	97	case FILE_CHECK:
	98	default:
	99	iint->ima_file_status = status;
	100	break;
	101	}
	102	}
	103
	104	static void ima_cache_flags(struct integrity_iint_cache *iint, int func)
	105	{
089bc8e9	106	switch (func) {
d79d72e0 MZ	107	case MMAP_CHECK:
	108	iint->flags \|= (IMA_MMAP_APPRAISED \| IMA_APPRAISED);
	109	break;
	110	case BPRM_CHECK:
	111	iint->flags \|= (IMA_BPRM_APPRAISED \| IMA_APPRAISED);
	112	break;
	113	case MODULE_CHECK:
	114	iint->flags \|= (IMA_MODULE_APPRAISED \| IMA_APPRAISED);
	115	break;
	116	case FILE_CHECK:
	117	default:
	118	iint->flags \|= (IMA_FILE_APPRAISED \| IMA_APPRAISED);
	119	break;
	120	}
	121	}
	122
d3634d0f DK	123	void ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, int xattr_len,
	124	struct ima_digest_data *hash)
	125	{
	126	struct signature_v2_hdr *sig;
	127
3ea7a560	128	if (!xattr_value \|\| xattr_len < 2)
d3634d0f DK	129	return;
d3634d0f DK	130
3ea7a560 DK	131	switch (xattr_value->type) {
	132	case EVM_IMA_XATTR_DIGSIG:
	133	sig = (typeof(sig))xattr_value;
	134	if (sig->version != 2 \|\| xattr_len <= sizeof(*sig))
	135	return;
	136	hash->algo = sig->hash_algo;
	137	break;
	138	case IMA_XATTR_DIGEST_NG:
	139	hash->algo = xattr_value->digest[0];
	140	break;
	141	case IMA_XATTR_DIGEST:
	142	/* this is for backward compatibility */
	143	if (xattr_len == 21) {
	144	unsigned int zero = 0;
	145	if (!memcmp(&xattr_value->digest[16], &zero, 4))
	146	hash->algo = HASH_ALGO_MD5;
	147	else
	148	hash->algo = HASH_ALGO_SHA1;
	149	} else if (xattr_len == 17)
	150	hash->algo = HASH_ALGO_MD5;
	151	break;
	152	}
d3634d0f DK	153	}
	154
	155	int ima_read_xattr(struct dentry *dentry,
	156	struct evm_ima_xattr_data **xattr_value)
	157	{
	158	struct inode *inode = dentry->d_inode;
	159
	160	if (!inode->i_op->getxattr)
	161	return 0;
	162
	163	return vfs_getxattr_alloc(dentry, XATTR_NAME_IMA, (char **)xattr_value,
	164	0, GFP_NOFS);
	165	}
	166
2fe5d6de MZ	167	/*
	168	* ima_appraise_measurement - appraise file measurement
	169	*
	170	* Call evm_verifyxattr() to verify the integrity of 'security.ima'.
	171	* Assuming success, compare the xattr hash with the collected measurement.
	172	*
	173	* Return 0 on success, error code otherwise
	174	*/
d79d72e0	175	int ima_appraise_measurement(int func, struct integrity_iint_cache *iint,
d3634d0f DK	176	struct file file, const unsigned char filename,
	177	struct evm_ima_xattr_data *xattr_value,
	178	int xattr_len)
2fe5d6de	179	{
52a13284 MZ	180	static const char op[] = "appraise_data";
52a13284 MZ	181	char *cause = "unknown";
2fe5d6de MZ	182	struct dentry *dentry = file->f_dentry;
2fe5d6de MZ	183	struct inode *inode = dentry->d_inode;
2fe5d6de	184	enum integrity_status status = INTEGRITY_UNKNOWN;
3ea7a560	185	int rc = xattr_len, hash_start = 0;
2fe5d6de MZ	186
	187	if (!ima_appraise)
	188	return 0;
	189	if (!inode->i_op->getxattr)
	190	return INTEGRITY_UNKNOWN;
	191
2fe5d6de MZ	192	if (rc <= 0) {
	193	if (rc && rc != -ENODATA)
	194	goto out;
	195
	196	cause = "missing-hash";
	197	status =
	198	(inode->i_size == 0) ? INTEGRITY_PASS : INTEGRITY_NOLABEL;
	199	goto out;
	200	}
	201
8606404f	202	status = evm_verifyxattr(dentry, XATTR_NAME_IMA, xattr_value, rc, iint);
2fe5d6de MZ	203	if ((status != INTEGRITY_PASS) && (status != INTEGRITY_UNKNOWN)) {
	204	if ((status == INTEGRITY_NOLABEL)
	205	\|\| (status == INTEGRITY_NOXATTRS))
	206	cause = "missing-HMAC";
	207	else if (status == INTEGRITY_FAIL)
	208	cause = "invalid-HMAC";
	209	goto out;
	210	}
8606404f	211	switch (xattr_value->type) {
3ea7a560 DK	212	case IMA_XATTR_DIGEST_NG:
	213	/* first byte contains algorithm id */
	214	hash_start = 1;
8606404f	215	case IMA_XATTR_DIGEST:
0e5a247c DK	216	if (iint->flags & IMA_DIGSIG_REQUIRED) {
	217	cause = "IMA signature required";
	218	status = INTEGRITY_FAIL;
	219	break;
	220	}
3ea7a560 DK	221	if (xattr_len - sizeof(xattr_value->type) - hash_start >=
3ea7a560 DK	222	iint->ima_hash->length)
d3634d0f DK	223	/* xattr length may be longer. md5 hash in previous
	224	version occupied 20 bytes in xattr, instead of 16
	225	*/
3ea7a560	226	rc = memcmp(&xattr_value->digest[hash_start],
a35c3fb6 DK	227	iint->ima_hash->digest,
a35c3fb6 DK	228	iint->ima_hash->length);
c7c8bb23 DK	229	else
c7c8bb23 DK	230	rc = -EINVAL;
8606404f DK	231	if (rc) {
	232	cause = "invalid-hash";
	233	status = INTEGRITY_FAIL;
8606404f DK	234	break;
	235	}
	236	status = INTEGRITY_PASS;
	237	break;
	238	case EVM_IMA_XATTR_DIGSIG:
	239	iint->flags \|= IMA_DIGSIG;
	240	rc = integrity_digsig_verify(INTEGRITY_KEYRING_IMA,
b1aaab22	241	(const char *)xattr_value, rc,
a35c3fb6 DK	242	iint->ima_hash->digest,
a35c3fb6 DK	243	iint->ima_hash->length);
8606404f DK	244	if (rc == -EOPNOTSUPP) {
	245	status = INTEGRITY_UNKNOWN;
	246	} else if (rc) {
	247	cause = "invalid-signature";
	248	status = INTEGRITY_FAIL;
	249	} else {
	250	status = INTEGRITY_PASS;
	251	}
	252	break;
	253	default:
	254	status = INTEGRITY_UNKNOWN;
	255	cause = "unknown-ima-data";
	256	break;
2fe5d6de	257	}
8606404f	258
2fe5d6de MZ	259	out:
2fe5d6de MZ	260	if (status != INTEGRITY_PASS) {
8606404f DK	261	if ((ima_appraise & IMA_APPRAISE_FIX) &&
	262	(!xattr_value \|\|
	263	xattr_value->type != EVM_IMA_XATTR_DIGSIG)) {
def3e8b9 DK	264	if (!ima_fix_xattr(dentry, iint))
def3e8b9 DK	265	status = INTEGRITY_PASS;
2fe5d6de MZ	266	}
	267	integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, filename,
	268	op, cause, rc, 0);
8606404f	269	} else {
d79d72e0	270	ima_cache_flags(iint, func);
2fe5d6de	271	}
d79d72e0	272	ima_set_cache_status(iint, func, status);
2fe5d6de MZ	273	return status;
	274	}
	275
	276	/*
	277	* ima_update_xattr - update 'security.ima' hash value
	278	*/
	279	void ima_update_xattr(struct integrity_iint_cache iint, struct file file)
	280	{
	281	struct dentry *dentry = file->f_dentry;
	282	int rc = 0;
	283
8606404f DK	284	/* do not collect and update hash for digital signatures */
	285	if (iint->flags & IMA_DIGSIG)
	286	return;
	287
d3634d0f	288	rc = ima_collect_measurement(iint, file, NULL, NULL);
2fe5d6de MZ	289	if (rc < 0)
2fe5d6de MZ	290	return;
8606404f	291
2fe5d6de MZ	292	ima_fix_xattr(dentry, iint);
	293	}
	294
	295	/**
	296	* ima_inode_post_setattr - reflect file metadata changes
	297	* @dentry: pointer to the affected dentry
	298	*
	299	* Changes to a dentry's metadata might result in needing to appraise.
	300	*
	301	* This function is called from notify_change(), which expects the caller
	302	* to lock the inode's i_mutex.
	303	*/
	304	void ima_inode_post_setattr(struct dentry *dentry)
	305	{
	306	struct inode *inode = dentry->d_inode;
	307	struct integrity_iint_cache *iint;
	308	int must_appraise, rc;
	309
	310	if (!ima_initialized \|\| !ima_appraise \|\| !S_ISREG(inode->i_mode)
	311	\|\| !inode->i_op->removexattr)
	312	return;
	313
	314	must_appraise = ima_must_appraise(inode, MAY_ACCESS, POST_SETATTR);
	315	iint = integrity_iint_find(inode);
	316	if (iint) {
d79d72e0 MZ	317	iint->flags &= ~(IMA_APPRAISE \| IMA_APPRAISED \|
	318	IMA_APPRAISE_SUBMASK \| IMA_APPRAISED_SUBMASK \|
	319	IMA_ACTION_FLAGS);
2fe5d6de MZ	320	if (must_appraise)
2fe5d6de MZ	321	iint->flags \|= IMA_APPRAISE;
2fe5d6de MZ	322	}
	323	if (!must_appraise)
	324	rc = inode->i_op->removexattr(dentry, XATTR_NAME_IMA);
	325	return;
	326	}
42c63330 MZ	327
	328	/*
	329	* ima_protect_xattr - protect 'security.ima'
	330	*
	331	* Ensure that not just anyone can modify or remove 'security.ima'.
	332	*/
	333	static int ima_protect_xattr(struct dentry dentry, const char xattr_name,
	334	const void *xattr_value, size_t xattr_value_len)
	335	{
	336	if (strcmp(xattr_name, XATTR_NAME_IMA) == 0) {
	337	if (!capable(CAP_SYS_ADMIN))
	338	return -EPERM;
	339	return 1;
	340	}
	341	return 0;
	342	}
	343
	344	static void ima_reset_appraise_flags(struct inode *inode)
	345	{
	346	struct integrity_iint_cache *iint;
	347
	348	if (!ima_initialized \|\| !ima_appraise \|\| !S_ISREG(inode->i_mode))
	349	return;
	350
	351	iint = integrity_iint_find(inode);
	352	if (!iint)
	353	return;
	354
45e2472e	355	iint->flags &= ~IMA_DONE_MASK;
42c63330 MZ	356	return;
	357	}
	358
	359	int ima_inode_setxattr(struct dentry dentry, const char xattr_name,
	360	const void *xattr_value, size_t xattr_value_len)
	361	{
	362	int result;
	363
	364	result = ima_protect_xattr(dentry, xattr_name, xattr_value,
	365	xattr_value_len);
	366	if (result == 1) {
	367	ima_reset_appraise_flags(dentry->d_inode);
	368	result = 0;
	369	}
	370	return result;
	371	}
	372
	373	int ima_inode_removexattr(struct dentry dentry, const char xattr_name)
	374	{
	375	int result;
	376
	377	result = ima_protect_xattr(dentry, xattr_name, NULL, 0);
	378	if (result == 1) {
	379	ima_reset_appraise_flags(dentry->d_inode);
	380	result = 0;
	381	}
	382	return result;
	383	}