ima: accept previously set IMA_NEW_FILE

commit 1ac202e upstream. Modifying the attributes of a file makes ima_inode_post_setattr reset the IMA cache flags. So if the file, which has just been created, is opened a second time before the first file descriptor is closed, verification fails since the security.ima xattr has not been written yet. We therefore have to look at the IMA_NEW_FILE even if the file already existed. With this patch there should no longer be an error when cat tries to open testfile: $ rm -f testfile $ ( echo test >&3 ; touch testfile ; cat testfile ) 3>testfile A file being new is no reason to accept that it is missing a digital signature demanded by the policy. Signed-off-by: Daniel Glöckner <[email protected]> Signed-off-by: Mimi Zohar <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
anholt · May 25, 2017 · 9103425 · 9103425
1 parent ce7146c
commit 9103425
Showing 1 changed file with 3 additions and 2 deletions.
diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
@@ -204,10 +204,11 @@ int ima_appraise_measurement(enum ima_hooks func,
 
 		cause = "missing-hash";
 		status = INTEGRITY_NOLABEL;
-		if (opened & FILE_CREATED) {
+		if (opened & FILE_CREATED)
 			iint->flags |= IMA_NEW_FILE;
+		if ((iint->flags & IMA_NEW_FILE) &&
+		    !(iint->flags & IMA_DIGSIG_REQUIRED))
 			status = INTEGRITY_PASS;
-		}
 		goto out;
 	}