deadlock in ssh_channel_open_forward_unix

My ssh client deadlocked for 2 days, and I found the deadlock took place in ssh_channel_open_forward_unix

This is with the libssh of Ubuntu 24.04 (0.10.6/openssl/zlib)

Here is the stack I got by attaching gdb to the deadlocked client:

#0  0x0000792816f1b4cd in __GI___poll (fds=0x57f90e5349c0, nfds=1, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x0000792817542531 in ?? () from /lib/x86_64-linux-gnu/libssh.so.4
#2  0x000079281754c0ed in ?? () from /lib/x86_64-linux-gnu/libssh.so.4
#3  0x000079281754c2c1 in ?? () from /lib/x86_64-linux-gnu/libssh.so.4
#4  0x0000792817561dc1 in ?? () from /lib/x86_64-linux-gnu/libssh.so.4
#5  0x00007928175242b5 in ssh_channel_open_forward_unix () from /lib/x86_64-linux-gnu/libssh.so.4

The deadlock happened while rebooting the server it was connected to. The sequence of events that happened are:

1. The unix domain socket the client was connected to was closed when the service was killed by reboot
2. The client tried to reconnect immediately
3. The client managed to create a new ssh session because the ssh server was not killed by reboot yet
4. The client deadlocked when trying to connect to the socket

I guess that during the reboot, the ssh server was killed right in the middle of ssh_channel_open_forward_unix, and that may be what caused the deadlock. I did not manage to replicate the problem.