signal: Never allocate siginfo for SIGKILL or SIGSTOP

The SIGKILL and SIGSTOP signals are never delivered to userspace so
queued siginfo for these signals can never be observed.  Therefore
remove the chance of failure by never even attempting to allocate
siginfo in those cases.

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
This commit is contained in:
Eric W. Biederman 2018-09-03 09:50:36 +02:00
parent 0351505405
commit f149b31557

View file

@ -1054,10 +1054,11 @@ static int __send_signal(int sig, struct siginfo *info, struct task_struct *t,
result = TRACE_SIGNAL_DELIVERED;
/*
* fast-pathed signals for kernel-internal things like SIGSTOP
* or SIGKILL.
* Skip useless siginfo allocation for SIGKILL SIGSTOP,
* and kernel threads.
*/
if ((info == SEND_SIG_FORCED) || (t->flags & PF_KTHREAD))
if ((info == SEND_SIG_FORCED) ||
sig_kernel_only(sig) || (t->flags & PF_KTHREAD))
goto out_set;
/*