Linux vulnerability

What happened

In the Linux kernel, the following vulnerability has been resolved: netfilter: synproxy: add mutex to guard hook reference counting As the synproxy infrastructure register netfilter hooks on-demand when a user adds the first iptables target or nftables expression, if done concurrently they can race each other. Introduce a mutex to serialize the refcount control blocks access from both frontends. While a per namespace mutex might be more efficient, it is not needed for target/expression like SYNPROXY.

Affected versions

Linux: ad49d86e07a497e834cb06f2b151dccd75f8e148 through before 0ec9ddc1bda261a2c57636c74c8b4e53000102c9 (git); ad49d86e07a497e834cb06f2b151dccd75f8e148 through before 56ffbe3a08c01dcdb0d6adee9ce1e535bfb3b389 (git); ad49d86e07a497e834cb06f2b151dccd75f8e148 through before debc57b83d5b323df74bf010c8d50fe26ad2ed6b (git); ad49d86e07a497e834cb06f2b151dccd75f8e148 through before 0f8ba5e4c53d2e4a536aa68140beda9fe59b2f88 (git); ad49d86e07a497e834cb06f2b151dccd75f8e148 through before 640441348258220e78daed40528b85b8afcedab6 (git); ad49d86e07a497e834cb06f2b151dccd75f8e148 through before aaf80701dc2f7a48fe543961e21f8ca3924d587c (git); ad49d86e07a497e834cb06f2b151dccd75f8e148 through before fbf0591275f50eae5733c3d7a8cd6c1e79933ffa (git); ad49d86e07a497e834cb06f2b151dccd75f8e148 through before 2fcba19caaeb2a33017459d3430f057967bb91b6 (git); 5.3; V3.1.6 through before * (custom) Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

• Apply vendor-provided updates or mitigations.
• Review affected product exposure and access logs.