CVE Catalog

CVE-2026-98164

Unknown
Published: Translated: NVD NIST

Summary

In the Linux kernel, KVM x86/mmu's kvm_gfn_is_write_tracked() only checks the supplied memslot, but page tracking is per-address-space and shadow pages are shared across address spaces. With SMM, a GFN can be write-tracked in one address space and appear untracked in another. The fix checks the supplied slot first, then the slot for the other address space, preventing mmu_try_to_unsync_pages() from marking an upper-level shadow page unsync and triggering a BUG in pte_list_remove().

Risk Assessment

The vulnerability can lead to a system crash (BUG) in KVM, potentially enabling DoS attacks on virtual machines or the host.

Recommendation

Apply the Linux kernel patch that checks write tracking in all address spaces. Update the kernel to a patched version.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: KVM: x86/mmu: Check write tracking in all address spaces kvm_gfn_is_write_tracked() checks only the supplied memslot, but page tracking is per-address-space and shadow pages are shared across all address spaces. With SMM, a GFN can therefore be write-tracked in one address space and appear untracked through the other. Check the supplied slot first, then the slot for the other address space. This ensures all callers honor write tracking regardless of the active address space. In particular, it prevents mmu_try_to_unsync_pages() from marking an upper-level shadow page unsync and eventually triggering the BUG in pte_list_remove(). [invert direction of the conditional. - Paolo]

Vulnerability data from NVD (NIST) · CISA KEV · EPSS