Linux Kernel Internal Port Memory Leak Vulnerability in net/mlx5e TC

A memory leak vulnerability has been identified in the Linux kernel's net/mlx5e TC component. This issue arises when flow rules, particularly those forwarding packets from internal ports over tunnels with 'new' state connection tracking offload, are processed. The internal port object is linked to the flow's post-action rules, causing its reference count to increase. However, the corresponding decrement function is not called, preventing the object from being freed. This leak is reported by kmemleak as an unreferenced object.

Impact

Exploitation of this vulnerability leads to a memory leak, where internal port objects are not properly released, causing increased memory usage over time.

Reproduction

The vulnerability can be reproduced by creating flow rules that forward packets from internal ports over tunnels, while allowing 'new' state connection tracking offload. This setup will trigger the memory leak by failing to decrement the reference count of the internal port object, leaving it unfreed and unreferenced.

Remediation

Users can apply the latest patches available in the Linux kernel stable tree to address this vulnerability.