From f149b31557446aff9ca96d4be7e39cc266f6e7cc Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Mon, 3 Sep 2018 09:50:36 +0200 Subject: [PATCH] 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 Signed-off-by: "Eric W. Biederman" --- kernel/signal.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/kernel/signal.c b/kernel/signal.c index 20931a892ace..d7d1adf735f4 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -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; /*