About a week ago, we at TravelBird had this bizarre problem with nginx workers segfaulting on TLS connections from Safari and curl, but not Firefox or Chrome. Nginx logs would state the worker process exited on signal 11 and dmesg would show the feared nginx[12345]: segfault at 8 ip 000000000042a08d sp 00007fffe5eebca0 error 4 in nginx[400000+b9000]