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

[Oleg Nesterov]

On 06/05, zhongjiang wrote:
>
>  static int kill_something_info(int sig, struct siginfo *info, pid_t pid)
>  {
> -	int ret;
> +	int ret, vpid;
>  
>  	if (pid > 0) {
>  		rcu_read_lock();
> @@ -1395,8 +1395,12 @@ static int kill_something_info(int sig, struct siginfo *info, pid_t pid)
>  
>  	read_lock(&tasklist_lock);
>  	if (pid != -1) {
> +		if (pid == INT_MIN)
> +			vpid = INT_MAX;

Well, this probably needs a comment to explain that this is just "avoid ub".

And if we really want the fix, to me

	if (pid == INT_MIN)
		return -ESRCH;

at the start makes more sense...

Oleg.