ptrace: PTRACE_LISTEN forgets to unlock ->siglock

If PTRACE_LISTEN fails after lock_task_sighand() it doesn't drop ->siglock.

Reported-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Oleg Nesterov 2011-09-25 19:46:22 +02:00 committed by Linus Torvalds
parent b172e38e43
commit f9d81f61c8

View File

@ -744,20 +744,17 @@ int ptrace_request(struct task_struct *child, long request,
break;
si = child->last_siginfo;
if (unlikely(!si || si->si_code >> 8 != PTRACE_EVENT_STOP))
break;
child->jobctl |= JOBCTL_LISTENING;
/*
* If NOTIFY is set, it means event happened between start
* of this trap and now. Trigger re-trap immediately.
*/
if (child->jobctl & JOBCTL_TRAP_NOTIFY)
signal_wake_up(child, true);
if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) {
child->jobctl |= JOBCTL_LISTENING;
/*
* If NOTIFY is set, it means event happened between
* start of this trap and now. Trigger re-trap.
*/
if (child->jobctl & JOBCTL_TRAP_NOTIFY)
signal_wake_up(child, true);
ret = 0;
}
unlock_task_sighand(child, &flags);
ret = 0;
break;
case PTRACE_DETACH: /* detach a process that was attached. */