CVE-2026-63940

Description

In the Linux kernel, the following vulnerability has been resolved: KVM: SEV: Ignore Port I/O requests of length '0' Explicitly ignore Port I/O requests of length '0' (or count '0'), so that setting up the software scratch area (and other code) doesn't have to worry about underflowing the length, and to allow for WARNing on trying to configure the scratch area with len==0.

References

• https://git.kernel.org/stable/c/2254972d4d69e279ba4e87bf0968eb08ad0d3c92
• https://git.kernel.org/stable/c/3988bd2723de407ae90fa7a6f6029b4e60238c58
• https://git.kernel.org/stable/c/3b6035bc6bff20e89752ce4358bc4c9a9d5883f2
• https://git.kernel.org/stable/c/c30cde934c7813b4e3069765dac64ce3d31e34f2