On Friday, 25 October 2019 11:11:32 CEST Alexander Bokovoy wrote:
On pe, 25 loka 2019, Kees Bakker wrote:
>On 24-10-19 16:12, Alexander Bokovoy wrote:
>>On to, 24 loka 2019, Kees Bakker via FreeIPA-users wrote:
>>>Hey,
>>>
>>>With x2go [1] you can start a remote desktop. Going from UNIX (client) to
>>>UNIX (server) it will use SSH behinds the scenes.
>>>
>>>However, on a IPA client the x2goclient command fails with a segfault
>>>(somewhere in a ssh library). This is caused by the modified
>>>/etc/ssh/ssh_config. More specifically this
>>>
>>> ProxyCommand /usr/bin/sss_ssh_knownhostsproxy -p %p %h
>>>
>>>When you disable this line the x2go connection succeeds.
>>>
>>>[1]
https://wiki.x2go.org/doku.php
>>
>>If you could install debug packages and generate a backtrace, that would
>>be great as it would help to understand where it happens. Thanks in
>>advance!
>
>Hey Alexander,
>
>The segfault is in a library of the libssh-4 package. I don't know if that
>is something you wanted to be involved with. Anyway, here is the stack
>strace of the segfault.
Thanks. So the crash is in ssh_poll_set_events(). Andreas, do you have
any ideas?
Where is libssh installed from? It looks like this is libssh 0.8.0.
>segfault at 4 ip 00007f6e7e0d5eeb sp 00007f6e64e6ea88 error 6 in
>libssh.so.4.5.0
>
>After installing the dgbsym package and running from gdb I could get a
>stack trace
>
>Thread 6 "SshMasterConnec" received signal SIGSEGV, Segmentation fault.
>[Switching to Thread 0x7fffdf1a0700 (LWP 14736)]
>0x00007ffff7b89eeb in ssh_poll_set_events (p=0x7fffd40076b0, events=4) at
>./src/poll.c:349 349 ./src/poll.c: No such file or directory.
>(gdb) where
>#0 0x00007ffff7b89eeb in ssh_poll_set_events (p=0x7fffd40076b0, events=4)
>at ./src/poll.c:349 #1 0x00007ffff7b8d3c8 in ssh_socket_unbuffered_write
>(len=<optimized out>, buffer=<optimized out>, s=0x7fffd4003850) at
>./src/socket.c:574
>#2 ssh_socket_nonblocking_flush (s=s@entry=0x7fffd4003850) at
>./src/socket.c:667 #3 0x00007ffff7b8d4c4 in ssh_socket_write
>(s=0x7fffd4003850, buffer=<optimized out>, len=len@entry=64) at
>./src/socket.c:628
>#4 0x00007ffff7b846c3 in ssh_packet_write (session=0x7fffd4004bc0,
>session=0x7fffd4004bc0) at ./src/packet.c:1316 #5 packet_send2
>(session=session@entry=0x7fffd4004bc0) at ./src/packet.c:1386 #6
>0x00007ffff7b85315 in ssh_packet_send
>(session=session@entry=0x7fffd4004bc0) at ./src/packet.c:1411 #7
>0x00007ffff7b72d69 in channel_write_common (channel=0x7fffd40112e0,
>data=0x7fffdf11fce0, len=6, is_stderr=0) at ./src/channels.c:1357
>#8 0x0000555555640cc3 in ?? ()
>#9 0x0000555555644745 in ?? ()
>#10 0x00007ffff581de3c in ?? () from
>/usr/lib/x86_64-linux-gnu/libQtCore.so.4 #11 0x00007ffff558b6db in
>start_thread (arg=0x7fffdf1a0700) at pthread_create.c:463 #12
>0x00007ffff4d1388f in clone () at
>../sysdeps/unix/sysv/linux/x86_64/clone.S:95
--
Andreas Schneider asn(a)samba.org
Samba Team
www.samba.org
GPG-ID: 8DFF53E18F2ABC8D8F3C92237EE0FC4DCC014E3D