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.
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
--
Kees Bakker