CVE-2026-43012

A flaw was found in the Linux kernel's net/mlx5 driver. This vulnerability occurs when the switchdev mode fails to initialize or transition correctly, leading to an improper rollback to legacy mode. During this rollback, the system attempts to unregister an already unregistered uplink network device, which can cause a kernel panic. A local attacker or process could exploit this flaw to trigger a system crash, resulting in a Denial of Service (DoS).

A Moderate severity flaw exists in the Linux kernel's net/mlx5 driver, affecting systems with Mellanox network adapters. This vulnerability can lead to a kernel panic and system crash if the switchdev mode fails to initialize or transition correctly, causing an improper rollback. Exploitation requires local access to trigger the Denial of Service.

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 mitigate this issue, systems not requiring switchdev functionality for Mellanox network adapters should be configured to operate in legacy mode. This can be done using the devlink utility. For example, to set the eswitch mode to legacy for a device named mlx5_0: # devlink dev eswitch set mlx5_0 mode legacy Applying this configuration may require a network service restart or system reboot to ensure the change is fully active.