CVE-2025-40254

Name of the Vulnerable Software and Affected Versions Linux kernel versions prior to 6.17.0-rc4+

Description The Linux kernel contains a flaw in the Open vSwitch (OVS) component related to the handling of Network Service Header (NSH) fields within the set(nsh(...)) action. The validation process for this action is fundamentally flawed, leading to potential kernel crashes or unpredictable behavior. Specifically, the code incorrectly handles nested attributes, causing memory corruption during validation and flow installation. The issue stems from confusion between flags related to masked attributes and improper memory layout handling. Attempts to utilize this action result in either validation failure or a kernel crash, and even if a flow is installed, it will not function as intended due to mixed-up keys and masks. The functionality was never fully operational since its introduction.

Recommendations Versions prior to 6.17.0-rc4+ should be updated.