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From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date: Fri, 3 Dec 2021 11:55:12 -0300
Message-ID: <CAMXh4bVBP5EU+1Zi4fK+=GHr0Miytjb-_J3+336t8i=J+TnL2A@mail.gmail.com>
Subject: Re: segmentation fault with glibc-2.34
To: Andreas Fink <finkandreas@web.de>
Cc: libc-help <libc-help@sourceware.org>
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On Fri, Dec 3, 2021 at 10:38 AM Andreas Fink via Libc-help
<libc-help@sourceware.org> wrote:
>
> Hello,
> I have observed a crash in firefox with glibc-2.34 and have found a
> small reproducer.
> Is the sigsys signal handler valid? If yes, then there is a bug in
> glibc-2.34.
> If it is invalid to set the result in the context, I think the firefox
> sandbox is doing dodgy things.
>
> gcc test.c -lseccomp
> strace ./a.out

The seccomp filter *explicitly* blocks newfstatat, which might be used
by getpwuid.

>
> This test reproducer does not segfault with 2.33 (it gives a
> "Permission denied")
>
> Cheers
> Andreas