KVM: x86/mmu: WARN and clear role.invalid when creating a child shadow page (CVE-2026-80726) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-80726

KVM: x86/mmu: WARN and clear role.invalid when creating a child shadow page

Answer in brief

CVE-2026-80726 records a Unknown severity vulnerability in KVM: x86/mmu: WARN and clear role.invalid when creating a child shadow page. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 3, 2026Updated Sep 3, 2026Source checked Sep 3, 2026First seen by HOL Sep 3, 2026Material review Sep 3, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=a770f6f28b1a9287189f3dc8333eb694d9a2f0ab <9b7984692c18b22d6d61af3f53887fca7fddb0f1 \|\| >=a770f6f28b1a9287189f3dc8333eb694d9a2f0ab <f33ecb89d352348ed5e625f6747ac51ede254e1b \|\| >=a770f6f28b1a9287189f3dc8333eb694d9a2f0ab <0af4711862c5b818204d40b21f0859ad51c230e9 \|\| >=a770f6f28b1a9287189f3dc8333eb694d9a2f0ab <66bc868a33cf1de43f22a94acd8857e0fe33393f \|\| >=a770f6f28b1a9287189f3dc8333eb694d9a2f0ab <9f7760a2e962cbda0d096a27d394d14ad4d22928 \|\| >=a770f6f28b1a9287189f3dc8333eb694d9a2f0ab <5ec42d57655c690234c14aece6dd3f209778c1d8	9b7984692c18b22d6d61af3f53887fca7fddb0f1, f33ecb89d352348ed5e625f6747ac51ede254e1b, 0af4711862c5b818204d40b21f0859ad51c230e9, 66bc868a33cf1de43f22a94acd8857e0fe33393f, 9f7760a2e962cbda0d096a27d394d14ad4d22928, 5ec42d57655c690234c14aece6dd3f209778c1d8
Linux/Linuxgeneric	2.6.30	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 9b7984692c18b22d6d61af3f53887fca7fddb0f1 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 3, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 3, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 3, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: KVM: x86/mmu: WARN and clear role.invalid when creating a child shadow page Explicitly clear role.invalid when deriving a child shadow page's role from its parent to harden against bugs elsewhere in KVM, as violating KVM's invariant that invalid pages are NOT on the list of active MMU pages leads to use-after-free due to __kvm_mmu_prepare_zap_page() using list_add() instead of list_move() when processing an invalid shadow page, i.e. makes a bad situation far worse. Yell loudly if the parent is invalid, as it means KVM has missed a validity check, i.e. KVM is attempting to map memory using an invalid/obsolete root, but continue on as the child is otherwise still a valid shadow page. ================================================================== BUG: KASAN: slab-use-after-free in __kvm_mmu_get_shadow_page+0x1817/0x1860 [kvm] Write of size 8 at addr ff11000153dd1368 by task repro/853 CPU: 1 UID: 1000 PID: 853 Comm: repro Not tainted 7.2.0-rc2-3aec122bdcaf-next-vm #5 PREEMPT Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 Call Trace: <TASK> dump_stack_lvl+0x4b/0x70 print_report+0x153/0x49c kasan_report+0xbc/0xf0 __kvm_mmu_get_shadow_page+0x1817/0x1860 [kvm] mmu_alloc_root+0x141/0x320 [kvm] kvm_mmu_load+0x612/0x20f0 [kvm] kvm_arch_vcpu_ioctl_run+0x3dd5/0x6150 [kvm] kvm_vcpu_ioctl+0x5e4/0x10d0 [kvm] __x64_sys_ioctl+0x131/0x1b0 do_syscall_64+0x67/0x5f0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 </TASK> Allocated by task 853: kasan_save_stack+0x20/0x40 kasan_save_track+0x14/0x30 __kasan_slab_alloc+0x5f/0x70 kmem_cache_alloc_noprof+0xfe/0x2e0 __kvm_mmu_topup_memory_cache+0x135/0x530 [kvm] paging64_page_fault+0x318/0x1e30 [kvm] kvm_mmu_do_page_fault+0x21d/0x630 [kvm] kvm_mmu_page_fault+0x18c/0x17b0 [kvm] kvm_arch_vcpu_ioctl_run+0x1f35/0x6150 [kvm] kvm_vcpu_ioctl+0x5e4/0x10d0 [kvm] __x64_sys_ioctl+0x131/0x1b0 do_syscall_64+0x67/0x5f0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 Freed by task 853: kasan_save_stack+0x20/0x40 kasan_save_track+0x14/0x30 kasan_save_free_info+0x3b/0x60 __kasan_slab_free+0x43/0x70 kmem_cache_free+0xe2/0x400 kvm_mmu_commit_zap_page.part.0+0x1e2/0x310 [kvm] kvm_mmu_free_roots+0x283/0x560 [kvm] kvm_arch_vcpu_ioctl_run+0x33c8/0x6150 [kvm] kvm_vcpu_ioctl+0x5e4/0x10d0 [kvm] __x64_sys_ioctl+0x131/0x1b0 do_syscall_64+0x67/0x5f0 entry_SYSCALL_64_after_hwframe+0x4b/0x53

Quoted source text, attributed separately from HOL analysis.