pat: Linux AX25: `address already in use` error after first connection

I’ve got Direwolf running as a software TNC with the -p command, and I run kissattach to connect the Linux AX.25 stack to that port.

This works, and when I connect in Pat, my emails are sent and received, and Pat disconnects.

Afterwards, any attempts to connect again are met with:

Remote accepted 4BR6SH6JZATY
Transmitting [Re: Test] [offset 0]
FF
>FQ
2022/05/16 02:25:09 Disconnected.
2022/05/16 02:25:24 Connecting to N4POW-10 (ax25)...
2022/05/16 02:25:24 Unable to establish connection to remote: address already in use

Active AX.25 sockets
Dest       Source     Device  State        Vr/Vs    Send-Q  Recv-Q
N4POW-10   K1MLN-0    ax0     LISTENING    006/001  0       0     
N4POW-10   K1MLN-0    ???     LISTENING    002/004  0       0     
N4POW-10   K1MLN-0    ???     LISTENING    006/000  0       0     
N4POW-10   K1MLN-0    ???     LISTENING    005/002  0       0     
N4POW-10   K1MLN-0    ???     LISTENING    005/002  0       0     
N4POW-10   K1MLN-0    ???     LISTENING    005/002  0       0     
N4POW-10   K1MLN-0    ???     LISTENING    006/003  0       0     
N4POW-10   K1MLN-0    ???     LISTENING    006/000  0       0     
N4POW-10   K1MLN-0    ???     LISTENING    005/002  0       0     

$ sudo ifconfig ax0
ax0: flags=67<UP,BROADCAST,RUNNING>  mtu 255
        ax25 K1MLN-9  txqueuelen 10  (AMPR AX.25)
        RX packets 81  bytes 6678 (6.5 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 49  bytes 1397 (1.3 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

I have no similar problems when using simply axcall. I can connect and reconnect all day, even after Pat gets into this bad state. But Pat will not work.

Restarting Pat doesn’t resolve it - I have to restart everything all the way up to Direwolf.

Pat Version 0.12.1-2+b1 Direwolf Version 1.6 $ uname -rv 5.17.5-surface #3 SMP PREEMPT Sat May 7 16:37:05 UTC 2022 (A custom kernel for Surface Laptops running Debian)