Deadlock Vulnerability in Linux Kernel Affecting mlx5e Networking Driver

CVE-2026-80739

What is CVE-2026-80739?

A deadlock vulnerability exists in the mlx5e networking driver within the Linux kernel, specifically related to flow management. The issue arises when the function __mlx5e_add_fdb_flow() fails, leading to flow deletion via mlx5e_tc_del_flow(). The deletion improperly acquires the ESW devcom lock without checking the flow type, resulting in a potential deadlock scenario. To mitigate this, a new PEER flag has been introduced to identify flows created on peer devices, ensuring that proper locking protocols are followed, thus preventing recursive locking and enhancing system stability.

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