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CVE-2026-53359

KVM: x86: Fix shadow paging use-after-free due to unexpected role

HIGH 8.8

At a glance

Source
NVD
EPSS
EPSS 1.37 % · percentile 72 ()
State
PUBLISHED
Published
Updated
Assigner
Linux
NVD status
Modified

Description

In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Fix shadow paging use-after-free due to unexpected role Commit 0cb2af2ea66ad ("KVM: x86: Fix shadow paging use-after-free due to unexpected GFN") fixed a shadow paging mismatch between stored and computed GFNs; the bug could be triggered by changing a PDE mapping from outside the guest, and then deleting a memslot. The rmap_remove() call would miss entries created after the PDE change because the GFN of the leaf SPTE does not match the GFN of the struct kvm_mmu_page. A similar hole however remains if the modified PDE points to a non-leaf page. In this case the gfn can be made to match, but the role does not match: the original large 2MB page creates a kvm_mmu_page with direct=1, while the new 4KB needs a kvm_mmu_page with direct=0. However, kvm_mmu_get_child_sp() does not compare the role, and therefore reuses the page. The next step is installing a leaf (4KB) SPTE on the new path which records an rmap entry under the gfn resolved by the walk. But when that child is zapped its parent kvm_mmu_page has direct=1 and kvm_mmu_page_get_gfn() computes the gfn for the 4KB page as sp->gfn + index instead of using sp->shadowed_translation[] (or sp->gfns[] in older kernels). It therefore fails to remove the recorded entry. When the memslot is dropped the shadow page is freed but the rmap entry survives, as in the scenario that was already fixed. Code that later walks that gfn (dirty logging, MMU notifier invalidation, and so on) dereferences an sptep that lies in the freed page, causing the use-after-free.

Weaknesses (CWE)

References

Scores

VersionScoreVectorScored by
CVSS 3.1HIGH 8.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:HLinux
CVSS 3.1HIGH 8.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:HNVD · 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Secondary)

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
Linux · Linuxaffected 2032a93d66fa282ba0f2ea9152eeff9511fa9a96 < 0b5e8ead71e683bcf6232db16234cf7e6d553a23 ; affected 2032a93d66fa282ba0f2ea9152eeff9511fa9a96 < b1337aae5e194324e4810d561764e7793f8b3864 ; affected 2032a93d66fa282ba0f2ea9152eeff9511fa9a96 < 9291654d69e08542de37755cebe4d5b02c3170d1 ; affected 2032a93d66fa282ba0f2ea9152eeff9511fa9a96 < 2ad3afa40ac6aa340dada122f9abfa46c0a6eb35 ; affected 2032a93d66fa282ba0f2ea9152eeff9511fa9a96 < 5e470998a23e4c3d89ed24e8172cb22747e61efa ; affected 2032a93d66fa282ba0f2ea9152eeff9511fa9a96 < 1ae7d5a6db6c190ce183e3098ca0e0846e14d462
Linux · Linuxaffected 2.6.36 ; unaffected 0 < 2.6.36 ; unaffected 5.15.222 ≤ 5.15.* ; unaffected 6.1.177 ≤ 6.1.* ; unaffected 6.6.144 ≤ 6.6.* ; unaffected 6.12.95 ≤ 6.12.*

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD