Re: [PATCH v3 6/6] ima: Reset IMA_NONACTION_RULE_FLAGS after post_setattr
From: Mimi Zohar <zohar@linux.ibm.com>
Date: 2025-02-03 01:31:53
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On Wed, 2025-01-22 at 18:24 +0100, Roberto Sassu wrote:
From: Roberto Sassu <roberto.sassu@huawei.com>
Commit 11c60f23ed13 ("integrity: Remove unused macro
IMA_ACTION_RULE_FLAGS") removed the IMA_ACTION_RULE_FLAGS mask, due to it
not being used after commit 0d73a55208e9 ("ima: re-introduce own integrity
cache lock").
However, it seems that the latter commit mistakenly used the wrong mask
when moving the code from ima_inode_post_setattr() to process_measurement(). There
is no mention in the commit message about this
change and it looks quite important, since changing from IMA_ACTIONS_FLAGS
(later renamed to IMA_NONACTION_FLAGS) to IMA_ACTION_RULE_FLAGS was done by
commit 42a4c603198f0 ("ima: fix ima_inode_post_setattr").
Roberto, thank you for the detailed explanation. Could we summarize the problem as:
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 original change of resetting only the policy-specific flags and not the new file status, but with new mask 0xfb000000 since the policy-specific flags changed meanwhile. Also rename IMA_ACTION_RULE_FLAGS to IMA_NONACTION_RULE_FLAGS, to be consistent with IMA_NONACTION_FLAGS.
Instead of restoring the bit mask that is used only once, consider inlining the correct bit mask (e.g. IMA_NONACTION_FLAGS & ~IMA_NEW_FILE) and expanding the existing comment.
Cc: stable@vger.kernel.org # v4.16.x
Fixes: 11c60f23ed13 ("integrity: Remove unused macro IMA_ACTION_RULE_FLAGS")Please update the Fixes tag to refer to commit 0d73a55208e9.
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
quoted hunk ↗ jump to hunk
--- security/integrity/ima/ima.h | 1 + security/integrity/ima/ima_main.c | 2 +- 2 files changed, 2 insertions(+), 1 deletion(-)diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index e1a3d1239bee..615900d4150d 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h@@ -141,6 +141,7 @@ struct ima_kexec_hdr {/* IMA iint policy rule cache flags */ #define IMA_NONACTION_FLAGS 0xff000000 +#define IMA_NONACTION_RULE_FLAGS 0xfb000000 #define IMA_DIGSIG_REQUIRED 0x01000000 #define IMA_PERMIT_DIRECTIO 0x02000000 #define IMA_NEW_FILE 0x04000000diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 46adfd524dd8..7173dca20c23 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c@@ -275,7 +275,7 @@ static int process_measurement(struct file *file, const structcred *cred, /* reset appraisal flags if ima_inode_post_setattr was called */
Update the comment based on the original commit 42a4c603198f ("ima: fix
ima_inode_post_setattr") patch description.
thanks,
Mimi
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