segmentation fault on closure of call home connection

[RavikumarTulugu]

we are seeing a crash when the call home connection is closed from the other end, the ch_lock and ch_cond parameters are NULL and nc_session_free tries to grab a lock on NULL ch_lock. I am pasting the stack trace below. from the code analysis it looks like the locks are not being allocated for the child sessions on the parent call home session. Please advise.

#0 __GI___pthread_mutex_lock (mutex=0x0) at ../nptl/pthread_mutex_lock.c:65
#1 0x00007ffff76570d6 in nc_session_free (session=0x7fffe4001250, data_free=0x407acf <free_ds>)
at session.c:622
#2 0x0000000000408e7c in np2srv_del_session_clb (session=0x7fffe4001250) at main.c:756
#3 0x000000000040a5fd in worker_thread (arg=0x6e0240) at main.c:1302
#4 0x000000000040b056 in main (argc=3, argv=0x7fffffffe178) at main.c:1541

[michalvasko]

Hi,
firstly, you are right, locks are not allocated for child (Call Home server) session. But locking this lock is always conditioned on the session being NC_SERVER (Call Home client) so I do not know how this could have happened.

However, you are not using recent versions (neither libnetconf2 nor netopeer2 lines match) or you have some modifications so I cannot help you.

Regards,
Michal

[RavikumarTulugu]

I am sorry for a misleading statement, the session is server based and we are using latest code base ( we synced a few weeks back ) we have some internal changes to the code base, they are mostly cosmetic and no way interfere with the main functionality. i am trying to understand the call home locking pattern. Please keep this bug open so that some body else might also run in to this.

[michalvasko]

I have looked again if your situation could happen and I think it could if you created a new NETCONF session from an existing Call Home NETCONF session on the same SSH session (creating a new SSH channel only). If that is what you were doing, it should be fixed. If not, then I don't know how such a situation can occur.

Regards,
Michal

[RavikumarTulugu]

Yes you are right , there are multiple channels and a new session is being created on an existing call home session. Thanks for the fix. i was suspecting the exact line.