A use-after-free exists in the Linux Kernel in tc_new_tfilter that could
allow a local attacker to gain privilege escalation. The exploit requires
unprivileged user namespaces. We recommend upgrading past commit
04c2a47ffb13c29778e2a14e414ad4cb5a5db4b5

It was discovered that the network traffic control implementation in the
Linux kernel contained a use-after-free vulnerability. A local attacker
could use this to cause a denial of service (system crash) or possibly
execute arbitrary code.