CVE-2026-98164

KVM: x86/mmu: Check write tracking in all address spaces

MEDIUM
5.5
CVSS Score
Published: September 29, 2026 at 12:02 PM UTC
Updated: October 7, 2026 at 07:17 AM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.2%

Description

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]

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

4.2 ≤ v < 6.1.1874.2 ≤ v < 6.12.1084.2 ≤ v < 6.18.494.2 ≤ v < 6.6.1564.2 ≤ v < 7.1.134.2 ≤ v < 7.26.13 ≤ v < 6.18.496.19 ≤ v < 7.1.136.2 ≤ v < 6.6.1566.7 ≤ v < 6.12.108699023e239658e62da6f42f47d31b54788521ec17.2 rc17.2 rc27.2 rc37.2 rc47.2 rc5
Vendor states this is fixed in 09aa68552d2542cc6c23edd1568ac265dc5d886f (fixed)
Vendor states this is fixed in 0f38453cdb2e17566ccb7c0f3dabd5bd21caca26 (fixed)
Vendor states this is fixed in 429b6f43b4d8c98988fdca99e02dc156134e3d77 (fixed)
Vendor states this is fixed in c0a9bd5fca0b5f2dea32b0fc31350e71e8648112 (fixed)
Vendor states this is fixed in d8636c8f9f95d0fd1e2f6f1cad0d5757aa6f212a (fixed)
Vendor states this is fixed in ec8fcaf354c1cbb36755d48e9f5a00c9591349e5 (fixed)
Vendor states this is fixed in 4.2 (unaffected)
Vendor states this is fixed in 6.1.187 (unaffected)
Vendor states this is fixed in 6.12.108 (unaffected)
Vendor states this is fixed in 6.18.49 (unaffected)
Vendor states this is fixed in 6.6.156 (unaffected)
Vendor states this is fixed in 7.1.13 (unaffected)
Vendor states this is fixed in 7.2 (unaffected)

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-670

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