[SRU][Artful][PATCH 1/1] ima/policy: fix parsing of fsuuid

[Joseph Salisbury]

From: Mike Rapoport <rppt at linux.vnet.ibm.com>

BugLink: http://bugs.launchpad.net/bugs/1755804

The switch to uuid_t invereted the logic of verfication that &entry->fsuuid
is zero during parsing of "fsuuid=" rule. Instead of making sure the
&entry->fsuuid field is not attempted to be overwritten, we bail out for
perfectly correct rule.

Fixes: 787d8c530af7 ("ima/policy: switch to use uuid_t")

Signed-off-by: Mike Rapoport <rppt at linux.vnet.ibm.com>
Cc: stable at vger.kernel.org
Signed-off-by: Mimi Zohar <zohar at linux.vnet.ibm.com>
(cherry picked from commit 36447456e1cca853188505f2a964dbbeacfc7a7a)
Signed-off-by: Joseph Salisbury <joseph.salisbury at canonical.com>
---
 security/integrity/ima/ima_policy.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 95209a5..8daf16e 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -743,7 +743,7 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
 		case Opt_fsuuid:
 			ima_log_string(ab, "fsuuid", args[0].from);
 
-			if (uuid_is_null(&entry->fsuuid)) {
+			if (!uuid_is_null(&entry->fsuuid)) {
 				result = -EINVAL;
 				break;
 			}
-- 
2.7.4