KVM: x86/mmu: Drop/zap existing present SPTE even when creating an MMIO SPTE
Summary
| CVE | CVE-2026-23401 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-04-01 09:16:15 UTC |
| Updated | 2026-04-18 09:16:24 UTC |
| Description | In the Linux kernel, the following vulnerability has been resolved: KVM: x86/mmu: Drop/zap existing present SPTE even when creating an MMIO SPTE When installing an emulated MMIO SPTE, do so *after* dropping/zapping the existing SPTE (if it's shadow-present). While commit a54aa15c6bda3 was right about it being impossible to convert a shadow-present SPTE to an MMIO SPTE due to a _guest_ write, it failed to account for writes to guest memory that are outside the scope of KVM. E.g. if host userspace modifies a shadowed gPTE to switch from a memslot to emulted MMIO and then the guest hits a relevant page fault, KVM will install the MMIO SPTE without first zapping the shadow-present SPTE. ------------[ cut here ]------------ is_shadow_present_pte(*sptep) WARNING: arch/x86/kvm/mmu/mmu.c:484 at mark_mmio_spte+0xb2/0xc0 [kvm], CPU#0: vmx_ept_stale_r/4292 Modules linked in: kvm_intel kvm irqbypass CPU: 0 UID: 1000 PID: 4292 Comm: vmx_ept_stale_r Not tainted 7.0.0-rc2-eafebd2d2ab0-sink-vm #319 PREEMPT Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:mark_mmio_spte+0xb2/0xc0 [kvm] Call Trace: <TASK> mmu_set_spte+0x237/0x440 [kvm] ept_page_fault+0x535/0x7f0 [kvm] kvm_mmu_do_page_fault+0xee/0x1f0 [kvm] kvm_mmu_page_fault+0x8d/0x620 [kvm] vmx_handle_exit+0x18c/0x5a0 [kvm_intel] kvm_arch_vcpu_ioctl_run+0xc55/0x1c20 [kvm] kvm_vcpu_ioctl+0x2d5/0x980 [kvm] __x64_sys_ioctl+0x8a/0xd0 do_syscall_64+0xb5/0x730 entry_SYSCALL_64_after_hwframe+0x4b/0x53 RIP: 0033:0x47fa3f </TASK> ---[ end trace 0000000000000000 ]--- |
Risk And Classification
EPSS: 0.000560000 probability, percentile 0.174550000 (date 2026-04-21)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected a54aa15c6bda3ca7e2f9e040ba968a1da303e24f 20656cd1f243d3a154aac5dd1b823110b6906fe1 git | Not specified |
| CNA | Linux | Linux | affected a54aa15c6bda3ca7e2f9e040ba968a1da303e24f ed5909992f344a7d3f4024261e9f751d9618a27d git | Not specified |
| CNA | Linux | Linux | affected a54aa15c6bda3ca7e2f9e040ba968a1da303e24f fd28c5618699180cd69619801e9ae6a5266c0a22 git | Not specified |
| CNA | Linux | Linux | affected a54aa15c6bda3ca7e2f9e040ba968a1da303e24f 459158151a158a6703b49f3c9de0e536d8bd553f git | Not specified |
| CNA | Linux | Linux | affected a54aa15c6bda3ca7e2f9e040ba968a1da303e24f 695320de6eadb75aaed8be1787c4ce4c189e4c7b git | Not specified |
| CNA | Linux | Linux | affected a54aa15c6bda3ca7e2f9e040ba968a1da303e24f bce7fe59d43531623f3e43779127bfb33804925d git | Not specified |
| CNA | Linux | Linux | affected a54aa15c6bda3ca7e2f9e040ba968a1da303e24f aad885e774966e97b675dfe928da164214a71605 git | Not specified |
| CNA | Linux | Linux | affected 5.13 | Not specified |
| CNA | Linux | Linux | unaffected 5.13 semver | Not specified |
| CNA | Linux | Linux | unaffected 5.15.203 5.15.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.1.168 6.1.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.6.131 6.6.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.80 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.21 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.19.11 6.19.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.0 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/ed5909992f344a7d3f4024261e9f751d9618a27d | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/459158151a158a6703b49f3c9de0e536d8bd553f | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/bce7fe59d43531623f3e43779127bfb33804925d | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/695320de6eadb75aaed8be1787c4ce4c189e4c7b | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/aad885e774966e97b675dfe928da164214a71605 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/fd28c5618699180cd69619801e9ae6a5266c0a22 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/20656cd1f243d3a154aac5dd1b823110b6906fe1 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.