Re: [Dovecot] Crash in pop3 with version 2.2.12
Le 28 mars 2014 à 17:12, Urban Loesch a écrit : Hi, thanks for your fast help. Now pop3 works again without error. Thanks Urban Am 28.03.2014 15:03, schrieb Teemu Huovila: Thats my bad. This commit should fix it http://hg.dovecot.org/dovecot-2.2/rev/b0359910ec96. Thanks for reporting it. Teemu Huovila Hello, I'm still wondering... under which circumstances could the crash occur? Trying here to reproduce it with an unpatched 2.2.12, without success: LIST and UIDL always return consistent results, without crashes, and behave that way on several mailboxes. I'm asking, because the problem could thus be tied to some configurations/settings only (as Urban wrote: I saw some people on the list [...]); but the correction brought by b0359910ec96 is an unconditional one. On the other hand, the problem might be raised because of some particular combination of circumstances, which I can't reproduce now, but which I could face one day or another... Hence the question: to patch or not to patch? Many thanks in advance, Axel
Re: [Dovecot] Crash in pop3 with version 2.2.12
On 4/4/2014 11:18 πμ, Axel Luttgens wrote: I'm still wondering... under which circumstances could the crash occur? I was wondering the same thing. We are now running 2.2.12 in production for two weeks (unpatched) and we have not seen such an error (despite extensive use of POP3). Regards, Nick
Re: [Dovecot] Crash in pop3 with version 2.2.12
Hello On 04/04/2014 11:18 AM, Axel Luttgens wrote: I'm still wondering... under which circumstances could the crash occur? This issue occurs whenever the function src/pop3/pop3-commands.c:client_uidls_save() is called. The function is called when: The pop3 internal structure client-message_uidls_save is 1. This in turn happens when any of these is true: 1. pop3 logoutformat has %u 2. config setting pop3_uidl_duplicates is not the default allow 3. config setting pop3_save_uidl=yes The problem manifests in two different ways. 1) When the zlib plugin is active the executable crashed due to a segmentation fault. 2) If there is no zlib, the data returned by the UIDL command is off-by-one and the last data item is null. Without zlib the error might look something like this: C:uidl S:+OK S:1 0002533553b6 S:2 0003533553b6 S:3 0004533553b6 S:4 0005533553b6 S:5 0006533553b6 S:6 (null) S:. Hence the question: to patch or not to patch? Patch, if your setup will need to meet any of the three criteria triggering the issue, before 2.2.13 is released. br, Teemu Huovila
Re: [Dovecot] Crash in pop3 with version 2.2.12
Le 4 avr. 2014 à 10:37, Teemu Huovila a écrit : Hello On 04/04/2014 11:18 AM, Axel Luttgens wrote: I'm still wondering... under which circumstances could the crash occur? This issue occurs whenever the function src/pop3/pop3-commands.c:client_uidls_save() is called. The function is called when: The pop3 internal structure client-message_uidls_save is 1. This in turn happens when any of these is true: 1. pop3 logoutformat has %u 2. config setting pop3_uidl_duplicates is not the default allow 3. config setting pop3_save_uidl=yes The problem manifests in two different ways. 1) When the zlib plugin is active the executable crashed due to a segmentation fault. 2) If there is no zlib, the data returned by the UIDL command is off-by-one and the last data item is null. Without zlib the error might look something like this: C:uidl S:+OK S:1 0002533553b6 S:2 0003533553b6 S:3 0004533553b6 S:4 0005533553b6 S:5 0006533553b6 S:6 (null) S:. Hence the question: to patch or not to patch? Patch, if your setup will need to meet any of the three criteria triggering the issue, before 2.2.13 is released. Hello Teemu, Thank you very much for your kind and very detailed explanation. None of 1. to 3. apply here, so I guess I've just been lucky. On the other hand, I didn't notice that the patch applies to a very precise context (the client_uidls_save function); it should thus be safe to apply it in all cases (even if un-needed with some *current* configuration). Sincerely, Axel
[Dovecot] Crash in pop3 with version 2.2.12
Hi,
today I upgraded to version 2.2.12 under Debian Squeeze.
I saw some people on the list they had the same problems with version 2.2.11,
but which should have been fixed in version 2.2.12.
My logfile shows:
..
Mar 28 08:25:01 mailstore dovecot: pop3-login: Login: user=u...@domain.net,
method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=34568, secured,
session=Jp6RmaX1YAB/AAAB
Mar 28 08:25:06 mailstore dovecot: pop3(u...@domain.net pid:34568
session:Jp6RmaX1YAB/AAAB): Fatal: master: service(pop3): child 34568 killed
with
signal 11 (core dumped)
...
I made some more dubugging and I found that the pop3 process crashed on the
uidl command.
Here my output from telnet session:
..
root@mailstore: # telnet localhost 110
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
+OK Dovecot ready.
user u...@domain.net
+OK
pass PASS
+OK Logged in.
list
+OK 5 messages:
1 3492
2 21924
3 3525
4 3472
5 3273
.
uidl
Connection closed by foreign host.
...
Listing massages or retrieving messages works normally. Only on uidl command
the services crashes.
I made a backtrace.
- start backtrace -
Core was generated by `dovecot/pop3'.
Program terminated with signal 11, Segmentation fault.
#0 0x7f9dd8ca488d in vfprintf () from /lib/libc.so.6
(gdb) bt full
#0 0x7f9dd8ca488d in vfprintf () from /lib/libc.so.6
No symbol table info available.
#1 0x7f9dd8cc6732 in vsnprintf () from /lib/libc.so.6
No symbol table info available.
#2 0x7f9dd904d0db in str_vprintfa (str=0x11aa4f8, fmt=0x409184 %u %s,
args=0x7ab4fff0) at str.c:155
args2 = {{gp_offset = 16, fp_offset = 48, overflow_arg_area =
0x7ab500e0, reg_save_area = 0x7ab50010}}
init_size = 4231558
pos = 0
ret = value optimized out
ret2 = value optimized out
__FUNCTION__ = str_vprintfa
#3 0x004055ff in client_send_line (client=0x11d1e50, fmt=value
optimized out) at pop3-client.c:678
str = 0x11aa4f8
_data_stack_cur_id = 4
va = {{gp_offset = 32, fp_offset = 48, overflow_arg_area =
0x7ab500e0, reg_save_area = 0x7ab50010}}
ret = value optimized out
__FUNCTION__ = client_send_line
#4 0x004073cd in list_uidls_saved_iter (client=0x11d1e50,
ctx=0x11da3c0) at pop3-commands.c:666
found = true
#5 list_uids_iter (client=0x11d1e50, ctx=0x11da3c0) at pop3-commands.c:693
str = value optimized out
permanent_uidl = value optimized out
found = value optimized out
failed = value optimized out
#6 0x00407d88 in cmd_uidl (client=0x11d1e50, name=value optimized
out, args=0x408880 ) at pop3-commands.c:874
ctx = 0x0
seq = value optimized out
#7 client_command_execute (client=0x11d1e50, name=value optimized out,
args=0x408880 ) at pop3-commands.c:938
No locals.
#8 0x00405870 in client_handle_input (client=0x11d1e50) at
pop3-client.c:739
_data_stack_cur_id = 3
line = value optimized out
args = 0x408880
ret = value optimized out
#9 0x7f9dd903c3d6 in io_loop_call_io (io=0x11d2760) at ioloop.c:388
ioloop = 0x11b2740
t_id = 2
#10 0x7f9dd903d45f in io_loop_handler_run (ioloop=value optimized out) at
ioloop-epoll.c:220
ctx = 0x11b2aa0
event = 0x11b3900
list = 0x11b44d0
io = 0x51
tv = {tv_sec = 9, tv_usec = 999326}
msecs = value optimized out
ret = 1
i = 0
call = false
__FUNCTION__ = io_loop_handler_run
#11 0x7f9dd903c348 in io_loop_run (ioloop=0x11b2740) at ioloop.c:412
__FUNCTION__ = io_loop_run
#12 0x7f9dd8fea953 in master_service_run (service=0x11b25d0,
callback=0x409186) at master-service.c:566
No locals.
#13 0x00404ac7 in main (argc=1, argv=0x11b2390) at main.c:277
set_roots = {0x4094e0, 0x0}
login_set = {auth_socket_path = 0x11aa050
/var/run/dovecot/auth-master, postlogin_socket_path = 0x0,
postlogin_timeout_secs = 60, callback =
0x404ca0 login_client_connected,
failure_callback = 0x404c50 login_client_failed, request_auth_token
= 0}
service_flags = value optimized out
storage_service_flags = MAIL_STORAGE_SERVICE_FLAG_DISALLOW_ROOT
username = 0x0
c = value optimized out
(gdb) quit
- end backtrace -
And at least my pop3 configuration part:
- start config -
protocol pop3 {
mail_plugins = quota mail_log notify acl zlib stats
pop3_client_workarounds = outlook-no-nuls oe-ns-eoh
pop3_lock_session = yes
pop3_logout_format = bytes_sent=%o top=%t/%p, retr=%r/%b, del=%d/%m, size=%s
uidl_hash=%u session=%{session}
pop3_reuse_xuidl = yes
}
- end config -
Setting pop3_reuse_xuidl = no has noe effect. Always the same crash.
Thanks and regards
Urban Loesch
Re: [Dovecot] Crash in pop3 with version 2.2.12
Thats my bad. This commit should fix it http://hg.dovecot.org/dovecot-2.2/rev/b0359910ec96. Thanks for reporting it. Teemu Huovila
Re: [Dovecot] Crash in pop3 with version 2.2.12
Hi, thanks for your fast help. Now pop3 works again without error. Thanks Urban Am 28.03.2014 15:03, schrieb Teemu Huovila: Thats my bad. This commit should fix it http://hg.dovecot.org/dovecot-2.2/rev/b0359910ec96. Thanks for reporting it. Teemu Huovila
