ACK: [SRU][J][PATCH 0/1] CVE-2026-63940

[Ivan Hu]

Acked-by: Ivan Hu <ivan.hu at canonical.com>

On Tue, Oct 6, 2026 at 6:15 AM Rickey Castillo via kernel-team <
kernel-team at lists.ubuntu.com> wrote:

> https://ubuntu.com/security/CVE-2026-63940
>
> [ Impact ]
>
> 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.
>
> [ Fix ]
>
> 3b6035bc6bff ("KVM: SEV: Ignore Port I/O requests of length '0'")
> Applied cleany from linux-6.12.y
>
> [ Test Plan ]
>
> Build and boot tested.
>
> [ Where Problems Could Occur ]
>
> Running legacy, poorly optimized, or custom guest operating systems that
> repeatedly
> trigger these invalid zero-length operations, the host system logs could
> get
> heavily flooded
>
> Sean Christopherson (1):
>   KVM: SEV: Ignore Port I/O requests of length '0'
>
>  arch/x86/kvm/svm/sev.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
>
> --
> 2.53.0
>
>
> --
> kernel-team mailing list
> kernel-team at lists.ubuntu.com
> https://lists.ubuntu.com/mailman/listinfo/kernel-team
>
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