CVE-2024-1085

A double-free flaw was found in how the Linux kernel's NetFilter system marks whether a catch-all element is enabled. A local user could use this flaw to crash the system.

This flaw is rated as a having Moderate impact, because it can only be exploited by a local user with access to netfilter.

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.

1. This flaw can be mitigated by preventing the affected netfilter (nf_tables) kernel module from being loaded. For instructions on how to blacklist a kernel module, please see https://access.redhat.com/solutions/41278.

2. If the module cannot be disabled, on non-containerized deployments of Red Hat Enterprise Linux, the mitigation is to disable user namespaces:

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

On containerized deployments, such as Red Hat OpenShift Container Platform, do not use the second mitigation (disabling user namespaces) as the user namespaces are required for container functionality. The first mitigation (blacklisting nf_tables) is still viable for containerized deployments, providing the environment is not using netfilter.