diff --git a/kernel/ptrace.c b/kernel/ptrace.c index b760bae64cf1..aa94aee9d4c9 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -364,8 +364,14 @@ static int ptrace_attach(struct task_struct *task, long request, mutex_unlock(&task->signal->cred_guard_mutex); out: if (!retval) { - wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, - TASK_UNINTERRUPTIBLE); + /* + * We do not bother to change retval or clear JOBCTL_TRAPPING + * if wait_on_bit() was interrupted by SIGKILL. The tracer will + * not return to user-mode, it will exit and clear this bit in + * __ptrace_unlink() if it wasn't already cleared by the tracee; + * and until then nobody can ptrace this task. + */ + wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, TASK_KILLABLE); proc_ptrace_connector(task, PTRACE_ATTACH); }