lmtp segfault after upgrade

[Timo Sirainen]

On 2 May 2017, at 10.41, Tom Sommer <mail at tomsommer.dk> wrote:
> 
> (gdb) bt full
> #0  i_stream_seek (stream=0x21, v_offset=0) at istream.c:298
>        _stream = <value optimized out>
> #1  0x00007fe98391ff32 in i_stream_concat_read_next (stream=0x1efe6c0) at istream-concat.c:77
>        prev_input = 0x1ef1560
>        data = 0x0
>        data_size = <value optimized out>
>        size = <value optimized out>
> #2  i_stream_concat_read (stream=0x1efe6c0) at istream-concat.c:175

This isn't very obvious.. There hasn't been any changes to istream-concat code in 2.2.29 and I can't really think of any other changes either that could be causing these crashes. Do these crashes happen to all mail deliveries or only some (any idea of percentage)? Maybe only for deliveries that have multiple recipients (in different backends)? We'll try to reproduce, but I'd think someone else would have already noticed/complained if it was that badly broken..

What's your doveconf -n? Also can you try running via valgrind to see what it logs before the crash? :

service lmtp {
  executable = /usr/bin/valgrind --vgdb=no -q /usr/libexec/dovecot/lmtp # or whatever the lmtp path really is
}