The dns__nta_shutdown() could be run from different threads and it was accessing nta->timer unlocked. Don't check and stop the timer from dns__nta_shutdown() directly, but leave it for the async callback.
The dns__nta_shutdown() could be run from different threads and it was accessing nta->timer unlocked. Don't check and stop the timer from dns__nta_shutdown() directly, but leave it for the async callback.