CVE-2026-80739

A flaw was found in the Linux kernel. A race condition exists in the net/mlx5e driver's Traffic Control (TC) flow deletion mechanism. When a flow fails to be added, the deletion process attempts to acquire a lock without proper checks, leading to a recursive lock acquisition in certain 'peer flow' scenarios. This can result in a system deadlock, causing a denial of service.

This vulnerability is rated with a Low severity impact because triggering the flaw requires local administrative privileges (such as CAP_NET_ADMIN) to establish network traffic control filters on systems running specific Mellanox hardware. Under standard Red Hat Enterprise Linux deployments, hardware offload of traffic control flower rules across peer devices is not enabled by default and represents a specialized configuration. Consequently, unprivileged remote attackers cannot exploit this issue, and the blast radius is confined to localized denial of service caused by a kernel deadlock during failed rule insertion.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.