diff --git a/ipc/sem.c b/ipc/sem.c index 2bf535dd0b93..cc6af85d1b15 100644 --- a/ipc/sem.c +++ b/ipc/sem.c @@ -2148,6 +2148,7 @@ static long do_semtimedop(int semid, struct sembuf __user *tsops, * scenarios where we were awakened externally, during the * window between wake_q_add() and wake_up_q(). */ + rcu_read_lock(); error = READ_ONCE(queue.status); if (error != -EINTR) { /* @@ -2157,10 +2158,10 @@ static long do_semtimedop(int semid, struct sembuf __user *tsops, * overwritten by the previous owner of the semaphore. */ smp_mb(); + rcu_read_unlock(); goto out_free; } - rcu_read_lock(); locknum = sem_lock(sma, sops, nsops); if (!ipc_valid_object(&sma->sem_perm))