CVE-2024-36979

Name of the Vulnerable Software and Affected Versions Linux kernel versions prior to 6.6.37

Description The vulnerability is related to a use-after-free issue in the bridge's MST code. It was discovered that nothing prevents a VLAN from being freed while walking the list from the same path as the bridge's forward delay timer. The vulnerability can be exploited by making the br mst vlan set state function use an RCU read lock, ensuring that freed memory is not accessed. The issue is identified by a suspicious RCU usage warning.

Recommendations To resolve the issue, update the Linux kernel to version 6.6.37 or later. As a temporary workaround, consider disabling the br mst vlan set state function until a patch is available. Restrict access to the vulnerable module net/bridge/br mst.c to minimize the risk of exploitation. Avoid using the br forward delay timer expired function in the affected API endpoint until the issue is resolved.