Bug#857344: exim4-daemon-heavy: segfault in DKIM verification

[Andreas Metzler]

On 2017-03-10 nijel <michal at cihar.com> wrote:
> Package: exim4-daemon-heavy
> Version: 4.88-5
> Severity: important

> Dear Maintainer,

> When upgrading system to stretch, I've noticed occasional segfaults of
> exim.

> Backtrace:

> #0  __memcmp_sse2 () at ../sysdeps/x86_64/multiarch/../memcmp.S:57
> #1  0x000055ff73dfcccb in pdkim_finish_bodyhash (ctx=0x55ff74306ce0, ctx=0x55ff74306ce0) at pdkim.c:814
> #2  pdkim_feed_finish (ctx=0x55ff74306ce0, return_signatures=return_signatures at entry=0x55ff7404c108 <dkim_signatures>) at pdkim.c:1392
> #3  0x000055ff73d80079 in dkim_exim_verify_finish () at dkim.c:147
> #4  0x000055ff73da10f4 in receive_msg (extract_recip=extract_recip at entry=0) at receive.c:3272
> #5  0x000055ff73d5c210 in handle_smtp_call (accepted=0x7ffd6864a650, accept_socket=<optimized out>, listen_socket_count=<optimized out>, 
>     listen_sockets=0x55ff742f5740) at daemon.c:509
> #6  daemon_go () at daemon.c:2040
> #7  0x000055ff73d51363 in main (argc=3, cargv=0x7ffd6868ad98) at exim.c:4808

> The DKIM signature in the received mail seems to be (if I didn't mess 
> up something with gdb):

> "DKIM-Signature: a=rsa-sha1; c=relaxed/relaxed; d=am-nis.com;\n\ts=s512; l=18869; x=1489743197; h=From:To:Subject:Content-Type:\n\tDate:Message-ID; b=EUtdmveJf3sgSeaGgvvseKpfKtxEXTUfVsh8vTriUI/9y\n\tIpwbJXpFa+nSkKMPrQvD80B76wI7YLx+MYSoPusuw==\n"

> I'll try with 4.89 from unstable to see if that helps (though
> obviously I'm not able to reproduce this reliably).

Hello,

Looks like https://bugs.exim.org/show_bug.cgi?id=2029 which indeed should
be fixed in 4.89.

cu Andreas
-- 
`What a good friend you are to him, Dr. Maturin. His other friends are
so grateful to you.'
`I sew his ears on from time to time, sure'