[patch 16/26] FUTEX: Restore the dropped ERSCH fix

[Greg KH <gregkh@suse.de>]

[-- Attachment #1: futex-restore-the-dropped-ersch-fix.patch --]
[-- Type: text/plain, Size: 1221 bytes --]

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

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

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.

Results in a NULL pointer dereference in case the search fails.

Restore it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
 kernel/futex.c |   14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

--- linux-2.6.21.6.orig/kernel/futex.c
+++ linux-2.6.21.6/kernel/futex.c
@@ -390,14 +390,12 @@ static struct task_struct * futex_find_g
 
 	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;

--