search

travelping / upg-vpp

User Plane Gateway (UPG) based on VPP
Apache License 2.0
148 stars 51 forks source link

Fix crash in session delete (sparse_vec_free) #318

Closed miguelbf-alb closed 1 year ago

miguelbf-alb commented 1 year ago

I am facing several issues when the PFCP session is removed for a given UE, usually vpp/upg is left on a deadlock state and can't be used anymore. Debugging this further the culprit is in the call to sparse_vec_free. I guess the vec pointer has to be deferenced. Similar code flow exists on other parts of vpp (e.g. https://github.com/FDio/vpp/blob/9bc72ac8de6dcc74aa82fa6c3223e9f93b2dc3c2/src/vnet/udp/udp.c#L491-L510) Runtime testing this change and the deadlock is gone

regards

sergeymatov commented 1 year ago

From the code example you've provided port_nh_sv is still a pointer to vector, can be checked in lines 486 or 501 of file given. This code line will executed every time when PFCP session is about to be deleted, so it's covered by multiple test cases within the test/e2e set. Dereference is surely not needed, probably you hit different issue.

miguelbf-alb commented 1 year ago

@sergeymatov you're right, the argument on that snippet is actually a pointer to the vec pointer (hence the need for dereferencing it). Digging a bit more on this the actual root cause of this is on the implementation of sparse_vec_free on vpp 22.02. Updating the function implementation (specially by considering your commit https://github.com/FDio/vpp/commit/ac199fcd9ba16a9dc3657f8ee02c2a2c82a65417) fixes the issue. Sorry for wasting your time with this one.