Re: Potential security problem in patch: Fix reading /proc/<pid>/memwhen parent dies.

From: Linus Torvalds
Date: Thu Nov 18 2004 - 20:00:09 EST




On Thu, 18 Nov 2004, Alan Cox wrote:
>
> The original point of this was that if our parent changed then our new
> parent is not aware of our special status. As a result we can send
> random signals to init and since it does not see SIGCLD we can get
> zombies or worse when we exit.

How could we send random signals? That's what the "exit_signal" thing is
for, and the code does

if (p->exit_signal != -1)
p->exit_signal = SIGCHLD;

for that.

Is there any other way to set exit_signal afterwards? If so, I think we
should have a security check at _that_ point.

Linus
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