Re: [PATCH v2] signal: Avoid undefined behaviour in kill_something_info

From: Oleg Nesterov
Date: Mon Jun 05 2017 - 09:32:14 EST


On 06/05, zhongjiang wrote:
>
> --- a/kernel/signal.c
> +++ b/kernel/signal.c
> @@ -1395,6 +1395,12 @@ static int kill_something_info(int sig, struct siginfo *info, pid_t pid)
>
> read_lock(&tasklist_lock);
> if (pid != -1) {
> + /*
> + * -INT_MIN is undefined, it need to exclude following case to
> + * avoid the UBSAN detection.
> + */
> + if (pid == INT_MIN)
> + return -ESRCH;

you need to do this before read_lock(tasklist)

Oleg.