APPLIED[N/J]/Cmnt: [SRU][R/N/J][PATCH 0/3] CVE-2026-53359

[Stefan Bader]

On 10/07/2026 11:01, Cengiz Can via kernel-team wrote:
> https://ubuntu.com/security/CVE-2026-53359
> 
> [ Impact ]
> 
> KVM's shadow paging code contains a use-after-free flaw. When a PDE mapping is
> modified from outside the guest to point to a non-leaf page,
> kvm_mmu_get_child_sp() reuses an existing kvm_mmu_page without comparing the
> role, mixing a direct=1 large-page shadow page with a direct=0 4KB mapping. As
> a result, kvm_mmu_page_get_gfn() computes the wrong GFN when the child is
> zapped and fails to remove the recorded rmap entry, so freeing the memslot
> leaves a dangling rmap entry. Later code that walks that GFN (dirty logging,
> MMU notifier invalidation, and so on) dereferences an sptep in the freed page,
> causing a use-after-free.
> 
> [ Fix ]
> 
> resolute: clean cherry-pick
> noble: clean cherry-pick
> jammy: backported with AI-assisted adaptation
> bionic: backported with AI-assisted adaptation
> 
> [ Test Plan ]
> 
> Boot tested.
> 
> [ Where Problems Could Occur ]
> 
> A regression in this KVM x86 MMU shadow paging change could cause incorrect GFN
> or role handling, leading to broken guest memory mappings, spurious zapping, or
> crashes when running nested or shadow-paged guests.
> 

Applied to noble,jammy:linux/master-next. Already applied for resolute. 
Thanks.

-Stefan
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