From mboxrd@z Thu Jan  1 00:00:00 1970
From: Oleg Nesterov <oleg@redhat.com>
Subject: Re: Compat 32-bit syscall entry from 64-bit task!? [was: Re:
	[RFC,PATCH 1/2] seccomp_filters: system call filtering using BPF]
Date: Mon, 23 Jan 2012 17:56:44 +0100
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Cc: Indan Zupancic <indan@nul.nu>, Andi Kleen <andi@firstfloor.org>,
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To: Chris Evans <scarybeasts@gmail.com>
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On 01/18, Chris Evans wrote:
>
> Thanks, Oleg. Seems like this would be a nice change to have. As we
> can see, people do use ptrace() as a security technology.

OK, I'll send it.

> With this in place, you can also (where possible) set up the tracee
> with PR_SET_PDEATHSIG==SIGKILL. And then, you have defences again
> either of the tracer or tracee dying from a stray SIGKILL.

This can only help if the tracer is the natural parent, is it enough?

Indan suggested PTRACE_O_SIGKILL_ON_DEATH, perhaps it makes sense.

Oleg.