From bb6f907f23c29f3cf5e801985fdacb92f4a17fa7 Mon Sep 17 00:00:00 2001 From: Roberto Sassu Date: Tue, 7 Nov 2017 11:37:07 +0100 Subject: [PATCH] ima: do not update security.ima if appraisal status is not INTEGRITY_PASS BugLink: http://bugs.launchpad.net/bugs/1744213 commit 020aae3ee58c1af0e7ffc4e2cc9fe4dc630338cb upstream. Commit b65a9cfc2c38 ("Untangling ima mess, part 2: deal with counters") moved the call of ima_file_check() from may_open() to do_filp_open() at a point where the file descriptor is already opened. This breaks the assumption made by IMA that file descriptors being closed belong to files whose access was granted by ima_file_check(). The consequence is that security.ima and security.evm are updated with good values, regardless of the current appraisal status. For example, if a file does not have security.ima, IMA will create it after opening the file for writing, even if access is denied. Access to the file will be allowed afterwards. Avoid this issue by checking the appraisal status before updating security.ima. Signed-off-by: Roberto Sassu Signed-off-by: Mimi Zohar Signed-off-by: James Morris Signed-off-by: Greg Kroah-Hartman Signed-off-by: Khalid Elmously Signed-off-by: Stefan Bader --- security/integrity/ima/ima_appraise.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index 809ba70fbbbf..7d769b948de8 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -320,6 +320,9 @@ void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file) if (iint->flags & IMA_DIGSIG) return; + if (iint->ima_file_status != INTEGRITY_PASS) + return; + rc = ima_collect_measurement(iint, file, NULL, 0, ima_hash_algo); if (rc < 0) return; -- 2.39.5