In the Linux kernel through 4.19, a use-after-free can occur due to a race condition between fanoutadd from setsockopt and bind on an AFPACKET socket. This issue exists because of the 15fe076edea787807a7cdc168df832544b58eba6 incomplete fix for a race condition. The code mishandles a certain multithreaded case involving a packetdobind unregister action followed by a packetnotifier register action. Later, packetrelease operates on only one of the two applicable linked lists. The attacker can achieve Program Counter control.