I’ve had two Asterisk crashes today that seem to be caused by errors where chan->tech_pvt is pointing to something that can’t be deallocated and I think I see a reference count bug in the above function.

It contains:

if (data->chan_old_vsrc) {
ast_channel_unref(data->chan_old_vsrc);
}

Shouldn’t this also have:

data->chan_old_vsrc = NULL;

It seems to me that if it doesn’t and the next condition also isn’t true, then the next time this same code is executed, it’ll decrement the reference count of the old channel again, which is wrong since it hasn’t been decremented.

What am I missing?