1 files changed, 27 insertions, 3 deletions

diff --git a/kernel/futex.c b/kernel/futex.c
index d9b3a2228f9d..e7a35f1039e7 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -530,8 +530,25 @@ lookup_pi_state(u32 uval, struct futex_hash_bucket *hb,
                                 return -EINVAL;
 
                         WARN_ON(!atomic_read(&pi_state->refcount));
-                        WARN_ON(pid && pi_state->owner &&
-                                pi_state->owner->pid != pid);
+
+                        /*
+                         * When pi_state->owner is NULL then the owner died
+                         * and another waiter is on the fly. pi_state->owner
+                         * is fixed up by the task which acquires
+                         * pi_state->rt_mutex.
+                         *
+                         * We do not check for pid == 0 which can happen when
+                         * the owner died and robust_list_exit() cleared the
+                         * TID.
+                         */
+                        if (pid && pi_state->owner) {
+                                /*
+                                 * Bail out if user space manipulated the
+                                 * futex value.
+                                 */
+                                if (pid != task_pid_vnr(pi_state->owner))
+                                        return -EINVAL;
+                        }
 
                         atomic_inc(&pi_state->refcount);
                         *ps = pi_state;
@@ -758,6 +775,13 @@ static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_q *this)
         if (!pi_state)
                 return -EINVAL;
 
+        /*
+         * If current does not own the pi_state then the futex is
+         * inconsistent and user space fiddled with the futex value.
+         */
+        if (pi_state->owner != current)
+                return -EINVAL;
+
         raw_spin_lock(&pi_state->pi_mutex.wait_lock);
         new_owner = rt_mutex_next_owner(&pi_state->pi_mutex);
 
@@ -1971,7 +1995,7 @@ retry_private:
         /* Unqueue and drop the lock */
         unqueue_me_pi(&q);
 
-        goto out;
+        goto out_put_key;
 
 out_unlock_put_key:
         queue_unlock(&q, hb);