Re: siginfo pid not populated from ptrace?

From: Oleg Nesterov
Date: Mon Dec 10 2018 - 10:37:22 EST

On 12/06, Eric W. Biederman wrote:
> The challenge is that we could be delivering this to a zombie signal
> group leader.


> Sigh it is probably time that I dig in and figure out how to avoid that
> case which we need to fix anyway because we can get the permission
> checks wrong for multi-threaded processes that call setuid and friends.

this is another issue... I am sure we have already discussed this, but I
failed to find any link to the previous discussion.

> Once that is sorted your small change will at least be safe.

I don't think so, any sub-thread can dequeue SIGSTOP unless type == PIDTYPE_PID,
this has nothing to do with the problems connected to zombie leader, or I
misunderstood you.