The ping_unhash function in net/ipv4/ping.c in the Linux kernel through
4.10.8 is too late in obtaining a certain lock and consequently cannot
ensure that disconnect function calls are safe, which allows local users to
cause a denial of service (panic) by leveraging access to the protocol
value of IPPROTO_ICMP in a socket system call.

Daniel Jiang discovered that a race condition existed in the ipv4 ping
socket implementation in the Linux kernel. A local privileged attacker
could use this to cause a denial of service (system crash).

 tyhicks> Ubuntu doesn't enable unprivileged ping sockets by default