bridge mst

The bridge mst tag covers content related to the Multiple Spanning Tree (MST) protocol in the Linux kernel bridge implementation. A recent thread discusses CVE-2025-40297, a use-after-free vulnerability in the bridge MST code that could be triggered when MST handling bypasses a port's state during deletion, allowing FDB learning to race with port teardown. The upstream maintainers fixed the race by adding a vlan_group sanity check, and the patch has been merged into stable kernels. This tag is relevant for Linux system administrators, security researchers, and anyone managing L2 switching features in Linux environments who need to understand MST-related vulnerabilities and their mitigations.