diff --git a/kernel/futex.c b/kernel/futex.c
index 4eeb63de7e54..1f6d646eee4a 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -900,7 +900,7 @@ static int attach_to_pi_owner(u32 uval, union futex_key *key,
 	if (!p)
 		return -ESRCH;
 
-	if (!p->mm) {
+	if (unlikely(p->flags & PF_KTHREAD)) {
 		put_task_struct(p);
 		return -EPERM;
 	}