From: Roberto Sassu roberto.sassu@huawei.com
Commit 0d73a55208e9 ("ima: re-introduce own integrity cache lock") mistakenly reverted the performance improvement introduced in commit 42a4c603198f0 ("ima: fix ima_inode_post_setattr"). The unused bit mask was subsequently removed by commit 11c60f23ed13 ("integrity: Remove unused macro IMA_ACTION_RULE_FLAGS").
Restore the performance improvement by introducing the new mask IMA_NONACTION_RULE_FLAGS, equal to IMA_NONACTION_FLAGS without IMA_NEW_FILE, which is not a rule-specific flag.
Finally, reset IMA_NONACTION_RULE_FLAGS instead of IMA_NONACTION_FLAGS in process_measurement(), if the IMA_CHANGE_ATTR atomic flag is set (after file metadata modification).
With this patch, new files for which metadata were modified while they are still open, can be reopened before the last file close (when security.ima is written), since the IMA_NEW_FILE flag is not cleared anymore. Otherwise, appraisal fails because security.ima is missing (files with IMA_NEW_FILE set are an exception).
Cc: stable@vger.kernel.org # v4.16.x Fixes: 0d73a55208e9 ("ima: re-introduce own integrity cache lock") Signed-off-by: Roberto Sassu roberto.sassu@huawei.com --- security/integrity/ima/ima.h | 3 +++ security/integrity/ima/ima_main.c | 7 +++++-- 2 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index 24d09ea91b87..a4f284bd846c 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -149,6 +149,9 @@ struct ima_kexec_hdr { #define IMA_CHECK_BLACKLIST 0x40000000 #define IMA_VERITY_REQUIRED 0x80000000
+/* Exclude non-action flags which are not rule-specific. */ +#define IMA_NONACTION_RULE_FLAGS (IMA_NONACTION_FLAGS & ~IMA_NEW_FILE) + #define IMA_DO_MASK (IMA_MEASURE | IMA_APPRAISE | IMA_AUDIT | \ IMA_HASH | IMA_APPRAISE_SUBMASK) #define IMA_DONE_MASK (IMA_MEASURED | IMA_APPRAISED | IMA_AUDITED | \ diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 9b87556b03a7..b028c501949c 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -269,10 +269,13 @@ static int process_measurement(struct file *file, const struct cred *cred, 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 */ + /* + * Reset appraisal flags (action and non-action rule-specific) + * if ima_inode_post_setattr was called. + */ iint->flags &= ~(IMA_APPRAISE | IMA_APPRAISED | IMA_APPRAISE_SUBMASK | IMA_APPRAISED_SUBMASK | - IMA_NONACTION_FLAGS); + IMA_NONACTION_RULE_FLAGS);
/* * Re-evaulate the file if either the xattr has changed or the