CVE-2026-43468

A flaw was found in the net/mlx5 component of the Linux kernel. This vulnerability involves a deadlock condition that can occur when the eswitch_mode_set function attempts to acquire a devlink lock while the esw->work_queue is executing and also trying to acquire the same lock. This concurrent lock acquisition can lead to a system freeze or unresponsiveness, resulting in a Denial of Service (DoS).

This Moderate severity flaw in the Linux kernel's net/mlx5 component can lead to a system freeze, causing a Denial of Service. The vulnerability arises from a deadlock when the eswitch_mode_set function and the esw->work_queue concurrently attempt to acquire the same devlink lock. This issue specifically affects systems utilizing Mellanox network adapters where these functions are actively used.

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.

To prevent the mlx5_core kernel module from loading, create a file named /etc/modprobe.d/blacklist-mlx5.conf with the content blacklist mlx5_core. This action will disable Mellanox network adapters, impacting network functionality. After applying the change, regenerate the initramfs using dracut -f -v and reboot the system for the mitigation to take effect. A system restart is required.