CVE-2023-23455

A denial of service flaw was found in atm_tc_enqueue in net/sched/sch_atm.c in the Linux kernel. This issue may allow a local attacker to cause a denial of service due to type confusion. Non-negative numbers could indicate a TC_ACT_SHOT condition rather than valid classification results.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

The mitigation is to disable unprivileged user namespaces by setting user.max_user_namespaces to 0:

# echo "user.max_user_namespaces=0" > /etc/sysctl.d/userns.conf
# sysctl -p /etc/sysctl.d/userns.conf