* [PATCH v2] ima: fallback to using i_version to detect file change
@ 2026-02-13 17:49 Mimi Zohar
2026-02-13 19:51 ` Frederick Lawler
0 siblings, 1 reply; 3+ messages in thread
From: Mimi Zohar @ 2026-02-13 17:49 UTC (permalink / raw)
To: linux-integrity
Cc: Mimi Zohar, Frederick Lawler, Jeff Layton, Roberto Sassu,
Roberto Sassu
Commit db1d1e8b9867 ("IMA: use vfs_getattr_nosec to get the i_version")
replaced detecting file change based on i_version with
STATX_CHANGE_COOKIE.
On filesystems without STATX_CHANGE_COOKIE enabled, revert back to
detecting file change based on i_version.
On filesystems which do not support either, assume the file changed.
Reported-by: Roberto Sassu <roberto.sassu@huawei.com>
Fixes: db1d1e8b9867 ("IMA: use vfs_getattr_nosec to get the i_version")
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
---
Changelog v2:
- Use the real_inode's iversion to detect file change on overlayfs
- Add Roberto's Reported-by tag
security/integrity/ima/ima_api.c | 13 +++++++----
security/integrity/ima/ima_main.c | 39 ++++++++++++++++++++++++-------
2 files changed, 40 insertions(+), 12 deletions(-)
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index c35ea613c9f8..28cf1fe07f8f 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -267,15 +267,20 @@ int ima_collect_measurement(struct ima_iint_cache *iint, struct file *file,
goto out;
/*
- * Detecting file change is based on i_version. On filesystems
- * which do not support i_version, support was originally limited
- * to an initial measurement/appraisal/audit, but was modified to
- * assume the file changed.
+ * Detect file change based on STATX_CHANGE_COOKIE, when supported,
+ * and fallback to detecting file change based on i_version.
+ *
+ * On filesystems which did not support i_version, support was
+ * originally limited to an initial measurement/appraisal/audit,
+ * but was later modified to assume the file changed.
*/
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;
+ else if (IS_I_VERSION(real_inode))
+ i_version = inode_peek_iversion(real_inode);
+
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 1d6229b156fb..4fc383479847 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -180,6 +180,34 @@ static void ima_rdwr_violation_check(struct file *file,
"invalid_pcr", "open_writers");
}
+/*
+ * Detect file change based on STATX_CHANGE_COOKIE, when supported, and
+ * fallback to detecting file change based on i_version. On filesystems
+ * which do not support either, assume the file changed.
+ */
+static bool ima_detect_file_change(struct ima_iint_cache *iint,
+ struct inode *inode, struct file *file)
+{
+ struct kstat stat;
+ int result;
+
+ result = vfs_getattr_nosec(&file->f_path, &stat, STATX_CHANGE_COOKIE,
+ AT_STATX_SYNC_AS_STAT);
+
+ if (!result && stat.result_mask & STATX_CHANGE_COOKIE &&
+ stat.change_cookie != iint->real_inode.version)
+ return true;
+ else if (!(stat.result_mask & STATX_CHANGE_COOKIE) &&
+ IS_I_VERSION(inode) &&
+ !(inode_eq_iversion(inode, iint->real_inode.version)))
+ return true;
+ else if (!(stat.result_mask & STATX_CHANGE_COOKIE) &&
+ !(IS_I_VERSION(inode)))
+ return true;
+
+ return false;
+}
+
static void ima_check_last_writer(struct ima_iint_cache *iint,
struct inode *inode, struct file *file)
{
@@ -191,18 +219,13 @@ static void ima_check_last_writer(struct ima_iint_cache *iint,
mutex_lock(&iint->mutex);
if (atomic_read(&inode->i_writecount) == 1) {
- struct kstat stat;
-
clear_bit(IMA_EMITTED_OPENWRITERS, &iint->atomic_flags);
update = test_and_clear_bit(IMA_UPDATE_XATTR,
&iint->atomic_flags);
- 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->real_inode.version) {
+
+ if (iint->flags & IMA_NEW_FILE ||
+ ima_detect_file_change(iint, inode, file)) {
iint->flags &= ~(IMA_DONE_MASK | IMA_NEW_FILE);
iint->measured_pcrs = 0;
if (update)
--
2.53.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v2] ima: fallback to using i_version to detect file change
2026-02-13 17:49 [PATCH v2] ima: fallback to using i_version to detect file change Mimi Zohar
@ 2026-02-13 19:51 ` Frederick Lawler
2026-02-18 20:34 ` Mimi Zohar
0 siblings, 1 reply; 3+ messages in thread
From: Frederick Lawler @ 2026-02-13 19:51 UTC (permalink / raw)
To: Mimi Zohar; +Cc: linux-integrity, Jeff Layton, Roberto Sassu, Roberto Sassu
On Fri, Feb 13, 2026 at 12:49:47PM -0500, Mimi Zohar wrote:
> Commit db1d1e8b9867 ("IMA: use vfs_getattr_nosec to get the i_version")
> replaced detecting file change based on i_version with
> STATX_CHANGE_COOKIE.
>
> On filesystems without STATX_CHANGE_COOKIE enabled, revert back to
> detecting file change based on i_version.
>
> On filesystems which do not support either, assume the file changed.
>
Tested-by: Frederick Lawler <fred@cloudflare.com>
> Reported-by: Roberto Sassu <roberto.sassu@huawei.com>
> Fixes: db1d1e8b9867 ("IMA: use vfs_getattr_nosec to get the i_version")
> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
> ---
> Changelog v2:
> - Use the real_inode's iversion to detect file change on overlayfs
> - Add Roberto's Reported-by tag
>
> security/integrity/ima/ima_api.c | 13 +++++++----
> security/integrity/ima/ima_main.c | 39 ++++++++++++++++++++++++-------
> 2 files changed, 40 insertions(+), 12 deletions(-)
>
> diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
> index c35ea613c9f8..28cf1fe07f8f 100644
> --- a/security/integrity/ima/ima_api.c
> +++ b/security/integrity/ima/ima_api.c
> @@ -267,15 +267,20 @@ int ima_collect_measurement(struct ima_iint_cache *iint, struct file *file,
> goto out;
>
> /*
> - * Detecting file change is based on i_version. On filesystems
> - * which do not support i_version, support was originally limited
> - * to an initial measurement/appraisal/audit, but was modified to
> - * assume the file changed.
> + * Detect file change based on STATX_CHANGE_COOKIE, when supported,
> + * and fallback to detecting file change based on i_version.
> + *
> + * On filesystems which did not support i_version, support was
> + * originally limited to an initial measurement/appraisal/audit,
> + * but was later modified to assume the file changed.
> */
> 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;
> + else if (IS_I_VERSION(real_inode))
> + i_version = inode_peek_iversion(real_inode);
> +
> 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 1d6229b156fb..4fc383479847 100644
> --- a/security/integrity/ima/ima_main.c
> +++ b/security/integrity/ima/ima_main.c
> @@ -180,6 +180,34 @@ static void ima_rdwr_violation_check(struct file *file,
> "invalid_pcr", "open_writers");
> }
>
> +/*
> + * Detect file change based on STATX_CHANGE_COOKIE, when supported, and
> + * fallback to detecting file change based on i_version. On filesystems
> + * which do not support either, assume the file changed.
> + */
> +static bool ima_detect_file_change(struct ima_iint_cache *iint,
> + struct inode *inode, struct file *file)
> +{
> + struct kstat stat;
> + int result;
> +
> + result = vfs_getattr_nosec(&file->f_path, &stat, STATX_CHANGE_COOKIE,
> + AT_STATX_SYNC_AS_STAT);
> +
> + if (!result && stat.result_mask & STATX_CHANGE_COOKIE &&
> + stat.change_cookie != iint->real_inode.version)
> + return true;
> + else if (!(stat.result_mask & STATX_CHANGE_COOKIE) &&
> + IS_I_VERSION(inode) &&
> + !(inode_eq_iversion(inode, iint->real_inode.version)))
> + return true;
> + else if (!(stat.result_mask & STATX_CHANGE_COOKIE) &&
> + !(IS_I_VERSION(inode)))
> + return true;
> +
> + return false;
> +}
> +
> static void ima_check_last_writer(struct ima_iint_cache *iint,
> struct inode *inode, struct file *file)
> {
> @@ -191,18 +219,13 @@ static void ima_check_last_writer(struct ima_iint_cache *iint,
>
> mutex_lock(&iint->mutex);
> if (atomic_read(&inode->i_writecount) == 1) {
> - struct kstat stat;
> -
> clear_bit(IMA_EMITTED_OPENWRITERS, &iint->atomic_flags);
>
> update = test_and_clear_bit(IMA_UPDATE_XATTR,
> &iint->atomic_flags);
> - 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->real_inode.version) {
> +
> + if (iint->flags & IMA_NEW_FILE ||
> + ima_detect_file_change(iint, inode, file)) {
> iint->flags &= ~(IMA_DONE_MASK | IMA_NEW_FILE);
> iint->measured_pcrs = 0;
> if (update)
> --
> 2.53.0
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v2] ima: fallback to using i_version to detect file change
2026-02-13 19:51 ` Frederick Lawler
@ 2026-02-18 20:34 ` Mimi Zohar
0 siblings, 0 replies; 3+ messages in thread
From: Mimi Zohar @ 2026-02-18 20:34 UTC (permalink / raw)
To: Frederick Lawler
Cc: linux-integrity, Jeff Layton, Roberto Sassu, Roberto Sassu
On Fri, 2026-02-13 at 13:51 -0600, Frederick Lawler wrote:
> On Fri, Feb 13, 2026 at 12:49:47PM -0500, Mimi Zohar wrote:
> > Commit db1d1e8b9867 ("IMA: use vfs_getattr_nosec to get the i_version")
> > replaced detecting file change based on i_version with
> > STATX_CHANGE_COOKIE.
> >
> > On filesystems without STATX_CHANGE_COOKIE enabled, revert back to
> > detecting file change based on i_version.
> >
> > On filesystems which do not support either, assume the file changed.
> >
>
> Tested-by: Frederick Lawler <fred@cloudflare.com>
Thanks, Fred. It's temporarily queued in the next-integrity-testing branch.
>
^ permalink raw reply [flat|nested] 3+ messages in thread
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2026-02-18 20:34 ` Mimi Zohar
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