[Dovecot] segfault in Debian Squeeze + Dovecot 2.1.10

Joe Auty joe at netmusician.org
Mon Sep 24 22:03:46 EEST 2012 

>
> Timo Sirainen <mailto:tss at iki.fi>
> September 24, 2012 10:32 AM
>
> Well, the good news is that it crashes only after it has already 
> disconnected the client anyway. But I thought I fixed this bug in 
> v2.1.10 and I'm not able to reproduce it myself.. Having debugging 
> information available might show something useful. Try installing 
> dovecot-dbg package and getting the bt full again?

Thanks Timo, I have done so. Here is the results of my debugging info now:

  gdb /usr/lib/dovecot/imap-login /var/run/dovecot/login/core
GNU gdb (GDB) 7.0.1-debian
Copyright (C) 2009 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later 
<http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>...
Reading symbols from /usr/lib/dovecot/imap-login...Reading symbols from 
/usr/lib/debug/usr/lib/dovecot/imap-login...done.
(no debugging symbols found)...done.

warning: Can't read pathname for load map: Input/output error.
Reading symbols from /usr/lib/dovecot/libdovecot-login.so.0...Reading 
symbols from 
/usr/lib/debug/usr/lib/dovecot/libdovecot-login.so.0.0.0...done.
(no debugging symbols found)...done.
Loaded symbols for /usr/lib/dovecot/libdovecot-login.so.0
Reading symbols from /usr/lib/dovecot/libdovecot.so.0...Reading symbols 
from /usr/lib/debug/usr/lib/dovecot/libdovecot.so.0.0.0...done.
(no debugging symbols found)...done.
Loaded symbols for /usr/lib/dovecot/libdovecot.so.0
Reading symbols from /lib/libc.so.6...(no debugging symbols found)...done.
Loaded symbols for /lib/libc.so.6
Reading symbols from /usr/lib/libssl.so.0.9.8...(no debugging symbols 
found)...done.
Loaded symbols for /usr/lib/libssl.so.0.9.8
Reading symbols from /usr/lib/libcrypto.so.0.9.8...(no debugging symbols 
found)...done.
Loaded symbols for /usr/lib/libcrypto.so.0.9.8
Reading symbols from /lib/librt.so.1...(no debugging symbols found)...done.
Loaded symbols for /lib/librt.so.1
Reading symbols from /lib/libdl.so.2...(no debugging symbols found)...done.
Loaded symbols for /lib/libdl.so.2
Reading symbols from /lib64/ld-linux-x86-64.so.2...(no debugging symbols 
found)...done.
Loaded symbols for /lib64/ld-linux-x86-64.so.2
Reading symbols from /usr/lib/libz.so.1...(no debugging symbols 
found)...done.
Loaded symbols for /usr/lib/libz.so.1
Reading symbols from /lib/libpthread.so.0...(no debugging symbols 
found)...done.
Loaded symbols for /lib/libpthread.so.0
Core was generated by `dovecot/imap-login   ?'.
Program terminated with signal 11, Segmentation fault.
#0  hash_table_destroy (_table=0x28) at hash.c:106
106    hash.c: No such file or directory.
     in hash.c
(gdb) bt full
#0  hash_table_destroy (_table=0x28) at hash.c:106
         table = <value optimized out>
#1  0x00007ff300721054 in settings_parser_deinit (_ctx=<value optimized 
out>) at settings-parser.c:237
         ctx = 0x0
#2  0x00007ff30074633d in master_service_settings_cache_deinit 
(_cache=<value optimized out>)
     at master-service-settings-cache.c:86
         cache = 0x9f9a60
         entry = 0xa016e0
         next = 0x0
         __FUNCTION__ = "master_service_settings_cache_deinit"
#3  0x00007ff3009a5018 in main_deinit (binary=<value optimized out>, 
argc=2, argv=0x9f8370) at main.c:355
No locals.
#4  login_binary_run (binary=<value optimized out>, argc=2, 
argv=0x9f8370) at main.c:407
         set_pool = 0x9f8a30
         allow_core_dumps = <value optimized out>
         login_socket = <value optimized out>
         c = <value optimized out>
#5  0x00007ff3003c0c8d in __libc_start_main () from /lib/libc.so.6
No symbol table info available.
#6  0x0000000000402459 in _start ()
No symbol table info available.
(gdb)


>
>
> Joe Auty <mailto:joe at netmusician.org>
> September 23, 2012 7:05 AM
>>
>> Timo Sirainen <mailto:tss at iki.fi>
>> September 23, 2012 5:58 AM
>>
>>
>> You should have a similar log line about the crash in mail.log (or 
>> wherever "doveadm log find" says that errors get logged). Find those 
>> lines, then configure login processes to dump core files. This 
>> probably should work:
>>
>> service imap-login {
>> executable = imap-login -D
>> }
>>
>> Next time it crashes hopefully you'll have 
>> /var/run/dovecot/login/core* file(s). Get a gdb backtrace from it 
>> send it:
>>
>> gdb /usr/lib/dovecot/imap-login /var/run/dovecot/login/core
>> bt full
>
> I hope I'm doing this correctly!
>
> # gdb /usr/lib/dovecot/imap-login /var/run/dovecot/login/core
> GNU gdb (GDB) 7.0.1-debian
> Copyright (C) 2009 Free Software Foundation, Inc.
> License GPLv3+: GNU GPL version 3 or later 
> <http://gnu.org/licenses/gpl.html>
> This is free software: you are free to change and redistribute it.
> There is NO WARRANTY, to the extent permitted by law.  Type "show 
> copying"
> and "show warranty" for details.
> This GDB was configured as "x86_64-linux-gnu".
> For bug reporting instructions, please see:
> <http://www.gnu.org/software/gdb/bugs/>...
> Reading symbols from /usr/lib/dovecot/imap-login...(no debugging 
> symbols found)...done.
>
> warning: Can't read pathname for load map: Input/output error.
> Reading symbols from /usr/lib/dovecot/libdovecot-login.so.0...(no 
> debugging symbols found)...done.
> Loaded symbols for /usr/lib/dovecot/libdovecot-login.so.0
> Reading symbols from /usr/lib/dovecot/libdovecot.so.0...(no debugging 
> symbols found)...done.
> Loaded symbols for /usr/lib/dovecot/libdovecot.so.0
> Reading symbols from /lib/libc.so.6...(no debugging symbols 
> found)...done.
> Loaded symbols for /lib/libc.so.6
> Reading symbols from /usr/lib/libssl.so.0.9.8...(no debugging symbols 
> found)...done.
> Loaded symbols for /usr/lib/libssl.so.0.9.8
> Reading symbols from /usr/lib/libcrypto.so.0.9.8...(no debugging 
> symbols found)...done.
> Loaded symbols for /usr/lib/libcrypto.so.0.9.8
> Reading symbols from /lib/librt.so.1...(no debugging symbols 
> found)...done.
> Loaded symbols for /lib/librt.so.1
> Reading symbols from /lib/libdl.so.2...(no debugging symbols 
> found)...done.
> Loaded symbols for /lib/libdl.so.2
> Reading symbols from /lib64/ld-linux-x86-64.so.2...(no debugging 
> symbols found)...done.
> Loaded symbols for /lib64/ld-linux-x86-64.so.2
> Reading symbols from /usr/lib/libz.so.1...(no debugging symbols 
> found)...done.
> Loaded symbols for /usr/lib/libz.so.1
> Reading symbols from /lib/libpthread.so.0...(no debugging symbols 
> found)...done.
> Loaded symbols for /lib/libpthread.so.0
> Core was generated by `dovecot/imap-login   ?'.
> Program terminated with signal 11, Segmentation fault.
> #0  0x00007f789cd08e14 in hash_table_destroy () from 
> /usr/lib/dovecot/libdovecot.so.0
> (gdb) bt full
> #0  0x00007f789cd08e14 in hash_table_destroy () from 
> /usr/lib/dovecot/libdovecot.so.0
> No symbol table info available.
> #1  0x00007f789ccda054 in settings_parser_deinit () from 
> /usr/lib/dovecot/libdovecot.so.0
> No symbol table info available.
> #2  0x00007f789ccff33d in master_service_settings_cache_deinit () from 
> /usr/lib/dovecot/libdovecot.so.0
> No symbol table info available.
> #3  0x00007f789cf5e018 in login_binary_run () from 
> /usr/lib/dovecot/libdovecot-login.so.0
> No symbol table info available.
> #4  0x00007f789c979c8d in __libc_start_main () from /lib/libc.so.6
> No symbol table info available.
> #5  0x0000000000402459 in ?? ()
> No symbol table info available.
> #6  0x00007fff8a9c65f8 in ?? ()
> No symbol table info available.
> #7  0x000000000000001c in ?? ()
> No symbol table info available.
> #8  0x0000000000000002 in ?? ()
> No symbol table info available.
> #9  0x00007fff8a9c7e6a in ?? ()
> No symbol table info available.
> #10 0x00007fff8a9c7e7d in ?? ()
> No symbol table info available.
> #11 0x0000000000000000 in ?? ()
> No symbol table info available.
>
>
>>
>>
>> Joe Auty <mailto:joe at netmusician.org>
>> September 22, 2012 3:57 PM
>> Hello,
>>
>> I'm seeing a lot of these in my /var/log/messages in Debian Squeeze, 
>> I suspect this might be causing performance issues. Any suggestions 
>> what I can try to fix this?
>>
>>
>> I'm using the 2.1.10 packages obtained with the following in my 
>> sources.list:
>>
>> deb http://xi.rename-it.nl/debian/ stable-auto/dovecot-2.1 main
>>
>>
>> I need to use Dovecot 2.1.x because I need to support handling 
>> multiple SSL certs.
>> ------------------------------------------------------------------------
>
>
>
>
>
> Timo Sirainen <mailto:tss at iki.fi>
> September 23, 2012 5:58 AM
>
>
> You should have a similar log line about the crash in mail.log (or 
> wherever "doveadm log find" says that errors get logged). Find those 
> lines, then configure login processes to dump core files. This 
> probably should work:
>
> service imap-login {
> executable = imap-login -D
> }
>
> Next time it crashes hopefully you'll have 
> /var/run/dovecot/login/core* file(s). Get a gdb backtrace from it send it:
>
> gdb /usr/lib/dovecot/imap-login /var/run/dovecot/login/core
> bt full
>
>
> Joe Auty <mailto:joe at netmusician.org>
> September 22, 2012 3:57 PM
> Hello,
>
> I'm seeing a lot of these in my /var/log/messages in Debian Squeeze, I 
> suspect this might be causing performance issues. Any suggestions what 
> I can try to fix this?
>
>
> I'm using the 2.1.10 packages obtained with the following in my 
> sources.list:
>
> deb http://xi.rename-it.nl/debian/ stable-auto/dovecot-2.1 main
>
>
> I need to use Dovecot 2.1.x because I need to support handling 
> multiple SSL certs.
> ------------------------------------------------------------------------

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