Oracle Linux: CVE-2018-18559: ELSA-2019-0163: kernel security, bug fix, and enhancement update (IMPORTANT) (Multiple Advisories)

In the Linux kernel through 4.19, a use-after-free can occur due to a race condition between fanout_add from setsockopt and bind on an AF_PACKET socket. This issue exists because of the 15fe076edea787807a7cdc168df832544b58eba6 incomplete fix for a race condition. The code mishandles a certain multithreaded case involving a packet_do_bind unregister action followed by a packet_notifier register action. Later, packet_release operates on only one of the two applicable linked lists. The attacker can achieve Program Counter control.
A use-after-free flaw can occur in the Linux kernel due to a race condition between packet_do_bind() and packet_notifier() functions called for an AF_PACKET socket. An unprivileged, local user could use this flaw to induce kernel memory corruption on the system, leading to an unresponsive system or to a crash. Due to the nature of the flaw, privilege escalation cannot be fully ruled out.