[PATCH 4.15 23/55] ima/policy: fix parsing of fsuuid

[Greg Kroah-Hartman]

4.15-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx>

commit 36447456e1cca853188505f2a964dbbeacfc7a7a upstream.

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@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Mimi Zohar <zohar@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 security/integrity/ima/ima_policy.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- 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, st
 		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;
 			}