FUTEX: Restore the dropped ERSCH fix

The return value of futex_find_get_task() needs to be -ESRCH in case
that the search fails.  This was part of the original futex fixes and
got accidentally dropped, when the futex-tidy-up patch was split out.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Stable Team <stable@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 6 insertions, 8 deletions

diff --git a/kernel/futex.c b/kernel/futex.c
index df248f5e0836..45490bec5831 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -409,14 +409,12 @@ static struct task_struct * futex_find_get_task(pid_t pid)
 
         rcu_read_lock();
         p = find_task_by_pid(pid);
-        if (!p)
-                goto out_unlock;
-        if ((current->euid != p->euid) && (current->euid != p->uid)) {
-                p = NULL;
-                goto out_unlock;
-        }
-        get_task_struct(p);
-out_unlock:
+
+        if (!p || ((current->euid != p->euid) && (current->euid != p->uid)))
+                p = ERR_PTR(-ESRCH);
+        else
+                get_task_struct(p);
+
         rcu_read_unlock();
 
         return p;