Re: [PATCH][2.4] cleanup ptrace secfix and fix most side effects

Bernhard Kaindl (bk@suse.de)
Fri, 9 May 2003 02:17:28 +0200 (CEST)


Alan wrote:
> Thinking about this harder
>
> A ptraced thread cannot go setuid since we don't permit the exec to do
> it
>
> A setuid thread marks the mm dumpable so no thread can be ptraced (since
> all threads inheriting the mm inherit it from the exec)

Agreed, this is the short form of what I tried to say.

> So ignore my earlier message

Thanks,
Bernd

On Fri, 9 May 2003, Bernhard Kaindl wrote:
>
> a) setuid requires execve() which decouples from the other thread
> and also gives the new thread a newly allocated task->mm.
>
> b) If the thread which calls execve() is being traced, execve ignores
> setuid.
>
> c) If the thread which calls execve() is being not traced, a tracer has
> to attach first, otherwise
...
> d)
...

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