CVE-2026-80667

A flaw was found in the Linux kernel's Mellanox (mlx5) network driver, specifically within the Multi-Port Ethernet Switch (MPESW) work handling for Link Aggregation Groups (LAG). When the mlx5_lag_get_devcom_comp() function returns a null value, the mlx5_mpesw_work() function fails to call complete(). This oversight can cause a process waiting for the work to finish to block indefinitely, leading to a denial of service (DoS) for the affected system.

A flaw in the Linux kernel's Mellanox (mlx5) network driver was rated as having low security impact for Red Hat products. The flaw is in the Multi-Port Ethernet Switch (MPESW) work handling for Link Aggregation Groups (LAG): when mlx5_lag_get_devcom_comp() returns NULL, mlx5_mpesw_work() returns early without calling complete(), so a caller that queued the work and waits on the completion object can block indefinitely, causing a local denial of service. Triggering the vulnerable path requires local access and specific LAG/MPESW configuration on Mellanox hardware; it is not reachable through ordinary network traffic, and it affects availability only, with no impact on confidentiality or integrity. Red Hat Enterprise Linux 6, 7, and 8 and the RHEL 9.2.0.z and 9.4.z streams are not affected because the vulnerable code is not present there, while the kernel and kernel-rt packages in RHEL 9.6.z, 9.8.z, 9.9, and 9.10, the kernel packages in RHEL 10.0.z, 10.2.z, 10.3, and 10.4, and the kernel and kernel-ivos-qualcomm packages in Red Hat In-Vehicle OS 2.0 and 2.1 are affected. The fix for the affected streams is currently deferred given the low impact; the residual risk of deferral is limited to a local, hard-to-trigger hang in the mlx5 driver control path rather than memory corruption, information disclosure, or privilege escalation.

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.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.