A read-after-free memory flaw was found in the Linux kernel's garbage
collection for Unix domain socket file handlers in the way users call
close() and fget() simultaneously and can potentially trigger a race
condition. This flaw allows a local user to crash the system or escalate
their privileges on the system. This flaw affects Linux kernel versions
prior to 5.16-rc4.

Jann Horn discovered a race condition in the Unix domain socket
implementation in the Linux kernel that could result in a read-after-free.
A local attacker could use this to cause a denial of service (system crash)
or possibly execute arbitrary code.