Linux Kernel CVE-2025-39973

In the Linux kernel, the following vulnerability has been resolved:

i40e: add validation for ring_len param

The ring_len parameter provided by the virtual function (VF) is assigned directly to the hardware memory context (HMC) without any validation.

To address this, introduce an upper boundary check for both Tx and Rx queue lengths. The maximum number of descriptors supported by the hardware is 8k-32. Additionally, enforce alignment constraints: Tx rings must be a multiple of 8, and Rx rings must be a multiple of 32.

The Linux kernel's i40e network driver (Intel Ethernet 700 Series controllers) in SR-IOV configurations is affected. No CPE strings were supplied in the feed and exact fixed kernel version tags are not enumerated; instead the fix is distributed across multiple stable-tree commits (git.kernel.org/stable/c/0543d40d..., 05fe81fb..., 45a7527c..., 55d22567..., 7d749e38..., afec12ad..., c0c83f4c..., d3b0d3f8...), indicating backports to several maintained stable branches. Affected version ranges should be determined per distribution kernel by checking whether these commits are present; consult your distribution's CVE tracker (e.g., the referenced kernel.org stable commits) for the precise fixed build.