KVM: x86: Fix shadow paging use-after-free due to unexpected GFN
In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Fix shadow paging use-after-free due to unexpected GFN The shadow MMU computes GFNs for direct shadow pages using sp->gfn plus the SPTE index. This assumption breaks for shadow paging if the guest page tables are modified between VM entries (similar to commit aad885e77496, "KVM: x86/mmu: Drop/zap existing present SPTE even when creating an MMIO SPTE", 2026-03-27). The flow is as follows: - a PDE is installed for a 2MB mapping, and a page in that area is accessed. KVM creates a kvm_mmu_page consisting of 512 4KB pages; the kvm_mmu_page is marked by FNAME(fetch) as direct-mapped because the guest's mapping is a huge page (and thus contiguous). - the PDE mapping is changed from outside the guest. - the guest accesses another page in the same 2MB area. KVM installs a new leaf SPTE and rmap entry; the SPTE uses the "correct" GFN (i.e. based on the new mapping, as changed in the previous step) but that GFN is outside of the [sp->gfn, sp->gfn + 511] range; therefore the rmap entry cannot be found and removed when the kvm_mmu_page is zapped. - the memslot that covers the first 2MB mapping is deleted, and the kvm_mmu_page for the now-invalid GPA is zapped. However, rmap_remove() only looks at the [sp->gfn, sp->gfn + 511] range established in step 1, and fails to find the rmap entry that was recorded by step 3. - any operation that causes an rmap walk for the same page accessed by step 3 then walks a stale rm
CVE-2026-46113
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-46113
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6aa8b732ca01c3d7a54e93f4d701b8aabbe60fb7",
"lessThan": "9597963a8ca16259d194a1d9950d7bd22a10ab2f",
"versionType": "git"
},
{
"status": "affected",
"version": "6aa8b732ca01c3d7a54e93f4d701b8aabbe60fb7",
"lessThan": "e9d4ea13aa2b6400bb10ec64b370ba3dadcd22f0",
"versionType": "git"
},
{
"status": "affected",
"version": "6aa8b732ca01c3d7a54e93f4d701b8aabbe60fb7",
"lessThan": "488e386484ec8c0e558be6e156edf34ed9f4d5c8",
"versionType": "git"
},
{
"status": "affected",
"version": "6aa8b732ca01c3d7a54e93f4d701b8aabbe60fb7",
"lessThan": "06c19c967b845b63172601fe459667d973b7e6b7",
"versionType": "git"
},
{
"status": "affected",
"version": "6aa8b732ca01c3d7a54e93f4d701b8aabbe60fb7",
"lessThan": "738ec97b1855df6c08fe2369f798fa0b972e556b",
"versionType": "git"
},
{
"status": "affected",
"version": "6aa8b732ca01c3d7a54e93f4d701b8aabbe60fb7",
"lessThan": "14d1e55dfd2cf4711bff164a6aaaddb783552134",
"versionType": "git"
},
{
"status": "affected",
"version": "6aa8b732ca01c3d7a54e93f4d701b8aabbe60fb7",
"lessThan": "0cb2af2ea66ad8ff195c156ea690f11216285bdf",
"versionType": "git"
}
],
"programFiles": [
"arch/x86/kvm/mmu/mmu.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "2.6.20"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "2.6.20",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.15.222",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.175",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.140",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.88",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.30",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.0.7",
"versionType": "semver",
"lessThanOrEqual": "7.0.*"
},
{
"status": "unaffected",
"version": "7.1",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"arch/x86/kvm/mmu/mmu.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-46113
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #40120 · Revision 1
- Added to Heist Feed
- Publisher date