Hi, sorry for the late reply.
The commit you've pointed at before is the commit introducing code for the
snippets.
Your claim that main is fixed is incorrect: I've bisected through the git
history, and the commit that "fixes" it, is the one flipping imapc features to
negatives: https://github.com/dovecot/core/commit/
7810b38d30b7dbb2155f78873fe760bc9e2e6212 However, the default imapc_features
value stays the same, so all the "negative" features are suddenly enabled.
I've reset the defaults in the frontend config to what it was before:
imapc_features = no-fetch-size no-fetch-headers no-search no-modseq no-delay-
login no-fetch-bodystructure no-acl
and then dovecot starts crashing again in the described scenario. It is the
"no-fetch-size" flag, and if I use "rfc822.size" feature on a 2.3 branch it
stops crashing.
Turns out this same feature adds some filter that seems to be meant for some
exchange email side-effect: https://github.com/dovecot/core/blob/main/src/lib-
storage/index/imapc/imapc-mail-fetch.c#L596 where this filter tries to remove
any X-Message-Flag header. This is weird, because it could have been an
normally received header as well as something that was tacked on later by
exchange.
The main bug is not fixed by just removing that filter: chaining filters is
probably very broken when using the imapc backend, and it might be broken in
other unknown scenarios.
Regards,
John
-----Original message-----
From: Aki Tuomi via dovecot <dovecot@dovecot.org>
Sent: Friday, 19th January 2024, 8:37
To: Aki Tuomi via dovecot <dovecot@dovecot.org>; John van der Kamp
<jk...@amazon.nl>
Subject: RE: Crash in dovecot snippet when using imapc
CAUTION: This email originated from outside of the organization. Do
not click links or open attachments unless you can confirm the sender
and know the content is safe.
Sorry, the provided patch link was wrong, it's already in 2.3.21, my
bad. Anyways, it is still fixed in main, since it does not happen
there.
Aki
> On 19/01/2024 09:13 EET Aki Tuomi via dovecot <dovecot@dovecot.org>
wrote:
>
>
> Hi!
>
> I was able to reproduce this issue with 2.3.21, but it seems to
have been fixed in main. I think https://github.com/dovecot/core/
commit/1c1b77dbf9a548aac788efb76973ce2d0fa6c732.patch will fix this.
>
> Aki
>
> > On 18/01/2024 22:51 EET John van der Kamp via dovecot
<dovecot@dovecot.org> wrote:
> >
> >
> > Hello,
> >
> >
> > I've found a crash in a very specific setup. A dovecot server
with imapc connection needs to receive an email with no body contents
for the intent of generating a preview/snippet. It crashes somewhere
deep in the jungle of istream and snapshots. I've included a script
which sets up the systems to reproduce the crash.
> >
> >
> > I've tested this with several versions. 2.3.16 doesn't seem to be
affected, but 2.3.20 and 2.3.21 are affect.
> >
> >
> > For me it produces a traceback like this, using the ubuntu
version from here: https://packages.ubuntu.com/noble/dovecot-core
> >
> >
> > (gdb) bt
> > #0 __pthread_kill_implementation (no_tid=0, signo=6,
threadid=140530132887360) at ./nptl/pthread_kill.c:44
> > #1 __pthread_kill_internal (signo=6, threadid=140530132887360)
at ./nptl/pthread_kill.c:78
> > #2 __GI___pthread_kill (threadid=140530132887360,
signo=signo@entry=6) at ./nptl/pthread_kill.c:89
> > #3 0x00007fcfb8842476 in __GI_raise (sig=sig@entry=6) at ../
sysdeps/posix/raise.c:26
> > #4 0x00007fcfb88287f3 in __GI_abort () at ./stdlib/abort.c:79
> > #5 0x00007fcfb8b37fe5 in default_fatal_finish (status=0,
type=LOG_TYPE_PANIC) at ../lib/failures.c:465
> > #6 fatal_handler_real (ctx=<optimized out>, format=<optimized
out>, args=<optimized out>) at ../lib/failures.c:477
> > #7 0x00007fcfb8be50d7 in i_internal_fatal_handler
(ctx=<optimized out>, format=<optimized out>, args=<optimized out>)
at ../lib/failures.c:879
> > #8 0x00007fcfb8b37eea in i_panic (format=0x7fcfb8c29020 "file
%s: line %d (%s): assertion failed: (%s)") at ../lib/failures.c:530
> > #9 0x00007fcfb8b3387b in i_stream_header_filter_snapshot_free
(_snapshot=<optimized out>) at ../lib-mail/istream-header-filter.c:
663
> > #10 i_stream_header_filter_snapshot_free
(_snapshot=0x55dabe297a60) at ../lib-mail/istream-header-filter.c:655
> > #11 0x00007fcfb8bf25ac in i_stream_snapshot_free
(_snapshot=_snapshot@entry=0x55dabe29b0d0) at ../lib/istream.c:253
> > #12 0x00007fcfb8bf2654 in i_stream_unref (stream=0x7ffc16cc7fa0)
at ../lib/istream.c:66
> > #13 0x00007fcfb8d96baa in index_mail_write_body_snippet
(mail=0x55dabe292058) at index/index-mail.c:1151
> > #14 0x00007fcfb8d97e48 in index_mail_parse_bodystructure
(mail=0x55dabe292058, field=MAIL_CACHE_BODY_SNIPPET) at index/index-
mail.c:1551
> > #15 0x00007fcfb8d97fe2 in index_mail_fetch_body_snippet
(value_r=0x7ffc16cc8050, mail=0x55dabe292058) at index/index-mail.c:
1602
> > #16 index_mail_get_special (_mail=0x55dabe292058,
field=<optimized out>, value_r=0x7ffc16cc8050) at index/index-mail.c:
1730
> > #17 0x00007fcfb8d16ffe in mail_get_special
(mail=mail@entry=0x55dabe292058,
field=field@entry=MAIL_FETCH_BODY_SNIPPET,
value_r=value_r@entry=0x7ffc16cc8050)
> > at /home/ubuntu/dovecot/new/dovecot-2.3.21+dfsg1/src/lib-
storage/mail.c:418
> > #18 0x000055dabc52645c in fetch_snippet (ctx=0x55dabe26e050,
mail=0x55dabe292058, preview=0x55dabe28f1f8) at ./src/imap/imap-
fetch-body.c:615
> > #19 0x000055dabc52b5cc in imap_fetch_more_int
(ctx=0x55dabe26e050, cancel=false) at ./src/imap/imap-fetch.c:562
> > #20 0x000055dabc52b8ad in imap_fetch_more (ctx=0x55dabe26e050,
cmd=0x55dabe26de98) at ./src/imap/imap-fetch.c:617
> > #21 0x000055dabc51fd07 in cmd_fetch (cmd=0x55dabe26de98) at ./
src/imap/cmd-fetch.c:382
> > #22 0x000055dabc528af4 in command_exec (cmd=0x55dabe26de98) at ./
src/imap/imap-commands.c:201
> > #23 0x000055dabc52e9e2 in client_command_input (cmd=<optimized
out>) at ./src/imap/imap-client.c:1237
> > #24 0x000055dabc52ea96 in client_command_input (cmd=<optimized
out>) at ./src/imap/imap-client.c:1307
> > #25 0x000055dabc52eeed in client_handle_next_command
(remove_io_r=<synthetic pointer>, client=0x55dabe26d2c8) at ./src/
imap/imap-client.c:1349
> > #26 client_handle_input (client=0x55dabe26d2c8) at ./src/imap/
imap-client.c:1363
> > #27 0x000055dabc52f2c4 in client_input (client=0x55dabe26d2c8) at
./src/imap/imap-client.c:1407
> > #28 0x00007fcfb8bfe27d in io_loop_call_io (io=0x55dabe26e660) at
../lib/ioloop.c:737
> > #29 0x00007fcfb8bff81a in io_loop_handler_run_internal
(ioloop=0x55dabe243fd0) at ../lib/ioloop-epoll.c:222
> > #30 0x00007fcfb8bff8d4 in io_loop_handler_run
(ioloop=0x55dabe243fd0) at ../lib/ioloop.c:789
> > #31 0x00007fcfb8bffa90 in io_loop_run (ioloop=0x55dabe243fd0) at
../lib/ioloop.c:762
> > #32 0x00007fcfb8b6ce57 in master_service_run
(service=0x55dabe243e20, callback=callback@entry=0x55dabc533210
<client_connected>) at ../lib-master/master-service.c:878
> > #33 0x000055dabc51ad37 in main (argc=<optimized out>,
argv=<optimized out>) at ./src/imap/main.c:575
> >
> >
> > John
> >
> >
> >
> > Hello,
> >
> > I've found a crash in a very specific setup. A dovecot server
with imapc
> > connection needs to receive an email with no body contents for
the intent of
> > generating a preview/snippet. It crashes somewhere deep in the
jungle of
> > istream and snapshots. I've included a script which sets up the
systems to
> > reproduce the crash.
> >
> > I've tested this with several versions. 2.3.16 doesn't seem to be
affected, but
> > 2.3.20 and 2.3.21 are affect.
> >
> > For me it produces a traceback like this, using the ubuntu
version from here:
> > https://packages.ubuntu.com/noble/dovecot-core
> >
> > (gdb) bt
> > #0 __pthread_kill_implementation (no_tid=0, signo=6,
threadid=140530132887360)
> > at ./nptl/pthread_kill.c:44
> > #1 __pthread_kill_internal (signo=6, threadid=140530132887360)
at ./nptl/
> > pthread_kill.c:78
> > #2 __GI___pthread_kill (threadid=140530132887360,
signo=signo@entry=6) at ./
> > nptl/pthread_kill.c:89
> > #3 0x00007fcfb8842476 in __GI_raise (sig=sig@entry=6) at ../
sysdeps/posix/
> > raise.c:26
> > #4 0x00007fcfb88287f3 in __GI_abort () at ./stdlib/abort.c:79
> > #5 0x00007fcfb8b37fe5 in default_fatal_finish (status=0,
type=LOG_TYPE_PANIC)
> > at ../lib/failures.c:465
> > #6 fatal_handler_real (ctx=<optimized out>, format=<optimized
out>,
> > args=<optimized out>) at ../lib/failures.c:477
> > #7 0x00007fcfb8be50d7 in i_internal_fatal_handler
(ctx=<optimized out>,
> > format=<optimized out>, args=<optimized out>) at ../lib/
failures.c:879
> > #8 0x00007fcfb8b37eea in i_panic (format=0x7fcfb8c29020 "file
%s: line %d
> > (%s): assertion failed: (%s)") at ../lib/failures.c:530
> > #9 0x00007fcfb8b3387b in i_stream_header_filter_snapshot_free
> > (_snapshot=<optimized out>) at ../lib-mail/istream-header-
filter.c:663
> > #10 i_stream_header_filter_snapshot_free
(_snapshot=0x55dabe297a60) at ../lib-
> > mail/istream-header-filter.c:655
> > #11 0x00007fcfb8bf25ac in i_stream_snapshot_free
> > (_snapshot=_snapshot@entry=0x55dabe29b0d0) at ../lib/istream.c:
253
> > #12 0x00007fcfb8bf2654 in i_stream_unref (stream=0x7ffc16cc7fa0)
at ../lib/
> > istream.c:66
> > #13 0x00007fcfb8d96baa in index_mail_write_body_snippet
(mail=0x55dabe292058)
> > at index/index-mail.c:1151
> > #14 0x00007fcfb8d97e48 in index_mail_parse_bodystructure
(mail=0x55dabe292058,
> > field=MAIL_CACHE_BODY_SNIPPET) at index/index-mail.c:1551
> > #15 0x00007fcfb8d97fe2 in index_mail_fetch_body_snippet
> > (value_r=0x7ffc16cc8050, mail=0x55dabe292058) at index/index-
mail.c:1602
> > #16 index_mail_get_special (_mail=0x55dabe292058,
field=<optimized out>,
> > value_r=0x7ffc16cc8050) at index/index-mail.c:1730
> > #17 0x00007fcfb8d16ffe in mail_get_special
(mail=mail@entry=0x55dabe292058,
> > field=field@entry=MAIL_FETCH_BODY_SNIPPET,
> > value_r=value_r@entry=0x7ffc16cc8050)
> > at /home/ubuntu/dovecot/new/dovecot-2.3.21+dfsg1/src/lib-
storage/mail.c:418
> > #18 0x000055dabc52645c in fetch_snippet (ctx=0x55dabe26e050,
> > mail=0x55dabe292058, preview=0x55dabe28f1f8) at ./src/imap/imap-
fetch-body.c:
> > 615
> > #19 0x000055dabc52b5cc in imap_fetch_more_int
(ctx=0x55dabe26e050,
> > cancel=false) at ./src/imap/imap-fetch.c:562
> > #20 0x000055dabc52b8ad in imap_fetch_more (ctx=0x55dabe26e050,
> > cmd=0x55dabe26de98) at ./src/imap/imap-fetch.c:617
> > #21 0x000055dabc51fd07 in cmd_fetch (cmd=0x55dabe26de98) at ./
src/imap/cmd-
> > fetch.c:382
> > #22 0x000055dabc528af4 in command_exec (cmd=0x55dabe26de98) at ./
src/imap/imap-
> > commands.c:201
> > #23 0x000055dabc52e9e2 in client_command_input (cmd=<optimized
out>) at ./src/
> > imap/imap-client.c:1237
> > #24 0x000055dabc52ea96 in client_command_input (cmd=<optimized
out>) at ./src/
> > imap/imap-client.c:1307
> > #25 0x000055dabc52eeed in client_handle_next_command
(remove_io_r=<synthetic
> > pointer>, client=0x55dabe26d2c8) at ./src/imap/imap-client.c:1349
> > #26 client_handle_input (client=0x55dabe26d2c8) at ./src/imap/
imap-client.c:
> > 1363
> > #27 0x000055dabc52f2c4 in client_input (client=0x55dabe26d2c8) at
./src/imap/
> > imap-client.c:1407
> > #28 0x00007fcfb8bfe27d in io_loop_call_io (io=0x55dabe26e660) at
../lib/
> > ioloop.c:737
> > #29 0x00007fcfb8bff81a in io_loop_handler_run_internal
(ioloop=0x55dabe243fd0)
> > at ../lib/ioloop-epoll.c:222
> > #30 0x00007fcfb8bff8d4 in io_loop_handler_run
(ioloop=0x55dabe243fd0) at ../
> > lib/ioloop.c:789
> > #31 0x00007fcfb8bffa90 in io_loop_run (ioloop=0x55dabe243fd0) at
../lib/
> > ioloop.c:762
> > #32 0x00007fcfb8b6ce57 in master_service_run
(service=0x55dabe243e20,
> > callback=callback@entry=0x55dabc533210 <client_connected>) at ../
lib-master/
> > master-service.c:878
> > #33 0x000055dabc51ad37 in main (argc=<optimized out>,
argv=<optimized out>) at
> > ./src/imap/main.c:575
> >
> > John
> >
> > _______________________________________________
> > dovecot mailing list -- dovecot@dovecot.org
> > To unsubscribe send an email to dovecot-le...@dovecot.org
> _______________________________________________
> dovecot mailing list -- dovecot@dovecot.org
> To unsubscribe send an email to dovecot-le...@dovecot.org
_______________________________________________
dovecot mailing list -- dovecot@dovecot.org
To unsubscribe send an email to dovecot-le...@dovecot.org
Amazon Development Center (Netherlands) B.V., Johanna Westerdijkplein
1, NL-2521 EN The Hague, Registration No. Chamber of Commerce
56869649, VAT: NL 852339859B01
_______________________________________________
dovecot mailing list -- dovecot@dovecot.org
To unsubscribe send an email to dovecot-le...@dovecot.org
