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authorJeff Layton <jlayton@kernel.org>2023-04-17 12:55:51 -0400
committerMimi Zohar <zohar@linux.ibm.com>2023-05-23 18:07:34 -0400
commitdb1d1e8b9867aae5c3e61ad7859abfcc4a6fd6c7 (patch)
treee8383eaf530258062aa0aa585adef06b5f9c3f38 /security
parentf1fcbaa18b28dec10281551dfe6ed3a3ed80e3d6 (diff)
IMA: use vfs_getattr_nosec to get the i_version
IMA currently accesses the i_version out of the inode directly when it does a measurement. This is fine for most simple filesystems, but can be problematic with more complex setups (e.g. overlayfs). Make IMA instead call vfs_getattr_nosec to get this info. This allows the filesystem to determine whether and how to report the i_version, and should allow IMA to work properly with a broader class of filesystems in the future. Reported-and-Tested-by: Stefan Berger <stefanb@linux.ibm.com> Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Diffstat (limited to 'security')
-rw-r--r--security/integrity/ima/ima_api.c9
-rw-r--r--security/integrity/ima/ima_main.c12
2 files changed, 14 insertions, 7 deletions
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index d3662f4acadc..c45902e72044 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -13,7 +13,6 @@
#include <linux/fs.h>
#include <linux/xattr.h>
#include <linux/evm.h>
-#include <linux/iversion.h>
#include <linux/fsverity.h>
#include "ima.h"
@@ -246,10 +245,11 @@ int ima_collect_measurement(struct integrity_iint_cache *iint,
struct inode *inode = file_inode(file);
const char *filename = file->f_path.dentry->d_name.name;
struct ima_max_digest_data hash;
+ struct kstat stat;
int result = 0;
int length;
void *tmpbuf;
- u64 i_version;
+ u64 i_version = 0;
/*
* Always collect the modsig, because IMA might have already collected
@@ -268,7 +268,10 @@ int ima_collect_measurement(struct integrity_iint_cache *iint,
* to an initial measurement/appraisal/audit, but was modified to
* assume the file changed.
*/
- i_version = inode_query_iversion(inode);
+ result = vfs_getattr_nosec(&file->f_path, &stat, STATX_CHANGE_COOKIE,
+ AT_STATX_SYNC_AS_STAT);
+ if (!result && (stat.result_mask & STATX_CHANGE_COOKIE))
+ i_version = stat.change_cookie;
hash.hdr.algo = algo;
hash.hdr.length = hash_digest_size[algo];
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index d66a0a36415e..365db0e43d7c 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -24,7 +24,6 @@
#include <linux/slab.h>
#include <linux/xattr.h>
#include <linux/ima.h>
-#include <linux/iversion.h>
#include <linux/fs.h>
#include "ima.h"
@@ -164,11 +163,16 @@ static void ima_check_last_writer(struct integrity_iint_cache *iint,
mutex_lock(&iint->mutex);
if (atomic_read(&inode->i_writecount) == 1) {
+ struct kstat stat;
+
update = test_and_clear_bit(IMA_UPDATE_XATTR,
&iint->atomic_flags);
- if (!IS_I_VERSION(inode) ||
- !inode_eq_iversion(inode, iint->version) ||
- (iint->flags & IMA_NEW_FILE)) {
+ if ((iint->flags & IMA_NEW_FILE) ||
+ vfs_getattr_nosec(&file->f_path, &stat,
+ STATX_CHANGE_COOKIE,
+ AT_STATX_SYNC_AS_STAT) ||
+ !(stat.result_mask & STATX_CHANGE_COOKIE) ||
+ stat.change_cookie != iint->version) {
iint->flags &= ~(IMA_DONE_MASK | IMA_NEW_FILE);
iint->measured_pcrs = 0;
if (update)