posix_timer: Fix error path in timer_create

Move CLOCK_DISPATCH(which_clock, timer_create, (new_timer)) after all
posible EFAULT erros.

*_timer_create may allocate/get resources.
(for example posix_cpu_timer_create does get_task_struct)

[ tglx: fold the remove crappy comment patch into this ]

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: <stable@kernel.org>
Reviewed-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 4 insertions, 7 deletions

diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c
index 00d1fda58ab6..ad723420acc3 100644
--- a/kernel/posix-timers.c
+++ b/kernel/posix-timers.c
@@ -559,14 +559,7 @@ SYSCALL_DEFINE3(timer_create, const clockid_t, which_clock,
         new_timer->it_id = (timer_t) new_timer_id;
         new_timer->it_clock = which_clock;
         new_timer->it_overrun = -1;
-        error = CLOCK_DISPATCH(which_clock, timer_create, (new_timer));
-        if (error)
-                goto out;
 
-        /*
-         * return the timer_id now.  The next step is hard to
-         * back out if there is an error.
-         */
         if (copy_to_user(created_timer_id,
                          &new_timer_id, sizeof (new_timer_id))) {
                 error = -EFAULT;
@@ -597,6 +590,10 @@ SYSCALL_DEFINE3(timer_create, const clockid_t, which_clock,
         new_timer->sigq->info.si_tid   = new_timer->it_id;
         new_timer->sigq->info.si_code  = SI_TIMER;
 
+        error = CLOCK_DISPATCH(which_clock, timer_create, (new_timer));
+        if (error)
+                goto out;
+
         spin_lock_irq(&current->sighand->siglock);
         new_timer->it_signal = current->signal;
         list_add(&new_timer->list, &current->signal->posix_timers);