{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-80726", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-26T14:34:25.789Z", "datePublished": "2026-09-03T08:21:45.923Z", "dateUpdated": "2026-09-04T04:58:16.442Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-09-04T04:58:16.442Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: x86/mmu: WARN and clear role.invalid when creating a child shadow page\n\nExplicitly clear role.invalid when deriving a child shadow page's role from\nits parent to harden against bugs elsewhere in KVM, as violating KVM's\ninvariant that invalid pages are NOT on the list of active MMU pages leads\nto use-after-free due to __kvm_mmu_prepare_zap_page() using list_add()\ninstead of list_move() when processing an invalid shadow page, i.e. makes a\nbad situation far worse.\n\nYell loudly if the parent is invalid, as it means KVM has missed a validity\ncheck, i.e. KVM is attempting to map memory using an invalid/obsolete root,\nbut continue on as the child is otherwise still a valid shadow page.\n\n ==================================================================\n BUG: KASAN: slab-use-after-free in __kvm_mmu_get_shadow_page+0x1817/0x1860 [kvm]\n Write of size 8 at addr ff11000153dd1368 by task repro/853\n\n CPU: 1 UID: 1000 PID: 853 Comm: repro Not tainted 7.2.0-rc2-3aec122bdcaf-next-vm #5 PREEMPT\n Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015\n Call Trace:\n \n dump_stack_lvl+0x4b/0x70\n print_report+0x153/0x49c\n kasan_report+0xbc/0xf0\n __kvm_mmu_get_shadow_page+0x1817/0x1860 [kvm]\n mmu_alloc_root+0x141/0x320 [kvm]\n kvm_mmu_load+0x612/0x20f0 [kvm]\n kvm_arch_vcpu_ioctl_run+0x3dd5/0x6150 [kvm]\n kvm_vcpu_ioctl+0x5e4/0x10d0 [kvm]\n __x64_sys_ioctl+0x131/0x1b0\n do_syscall_64+0x67/0x5f0\n entry_SYSCALL_64_after_hwframe+0x4b/0x53\n \n\n Allocated by task 853:\n kasan_save_stack+0x20/0x40\n kasan_save_track+0x14/0x30\n __kasan_slab_alloc+0x5f/0x70\n kmem_cache_alloc_noprof+0xfe/0x2e0\n __kvm_mmu_topup_memory_cache+0x135/0x530 [kvm]\n paging64_page_fault+0x318/0x1e30 [kvm]\n kvm_mmu_do_page_fault+0x21d/0x630 [kvm]\n kvm_mmu_page_fault+0x18c/0x17b0 [kvm]\n kvm_arch_vcpu_ioctl_run+0x1f35/0x6150 [kvm]\n kvm_vcpu_ioctl+0x5e4/0x10d0 [kvm]\n __x64_sys_ioctl+0x131/0x1b0\n do_syscall_64+0x67/0x5f0\n entry_SYSCALL_64_after_hwframe+0x4b/0x53\n\n Freed by task 853:\n kasan_save_stack+0x20/0x40\n kasan_save_track+0x14/0x30\n kasan_save_free_info+0x3b/0x60\n __kasan_slab_free+0x43/0x70\n kmem_cache_free+0xe2/0x400\n kvm_mmu_commit_zap_page.part.0+0x1e2/0x310 [kvm]\n kvm_mmu_free_roots+0x283/0x560 [kvm]\n kvm_arch_vcpu_ioctl_run+0x33c8/0x6150 [kvm]\n kvm_vcpu_ioctl+0x5e4/0x10d0 [kvm]\n __x64_sys_ioctl+0x131/0x1b0\n do_syscall_64+0x67/0x5f0\n entry_SYSCALL_64_after_hwframe+0x4b/0x53" } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H", "baseScore": 9.3, "baseSeverity": "CRITICAL" }, "scenarios": [ { "lang": "en", "value": "AV:L - The bug is reached only through host KVM x86 shadow-MMU handling on the KVM_RUN ioctl path (kvm_arch_vcpu_ioctl_run -> kvm_mmu_page_fault/kvm_mmu_load -> __kvm_mmu_get_shadow_page), driven by guest page faults and root reloads, not by remote network or physical input.\nAC:L - The reproducer (UID 1000) triggers this reliably by combining guest page-table churn with MMU reclaim (make_mmu_pages_available/kvm_mmu_zap_oldest_mmu_pages) so an in-use root is zapped invalid while children are still created; the attacker controls both fault and reclaim sides of the race.\nPR:N - Exploitation requires only code running inside an already-running KVM guest (or equivalent guest-driven KVM_RUN activity); no host root, CAP_SYS_ADMIN, or direct /dev/kvm access is needed beyond what any cloud VM tenant or compromised guest process already has.\nUI:N - Once the attacker can execute in the guest, triggering the fault/reclaim sequence is entirely self-driven through guest memory and paging behavior with no action required from another user or administrator.\nS:C - Corrupting host KVM MMU active_mmu_pages/list state from guest-controlled faults crosses the guest-to-host virtualization boundary and can compromise the host kernel beyond the guest security domain, enabling VM escape-class impact.\nC:H - The demonstrated slab use-after-free and broken active-list invariant (invalid children left linked while __kvm_mmu_prepare_zap_page uses list_add instead of list_move) provide attacker-influenced host heap corruption that can be leveraged for arbitrary kernel memory reads.\nI:H - The same UAF and doubly-linked list corruption on host kvm_mmu_page objects are writable memory-corruption primitives suitable for control-flow or structure hijacking, not merely benign accounting errors.\nA:H - KASAN reports a host slab UAF with an 8-byte write in __kvm_mmu_get_shadow_page, and list corruption on active_mmu_pages can cause host oops, panic, or hang, denying service to the host and co-located VMs." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/x86/kvm/mmu/mmu.c" ], "versions": [ { "version": "a770f6f28b1a9287189f3dc8333eb694d9a2f0ab", "lessThan": "9b7984692c18b22d6d61af3f53887fca7fddb0f1", "status": "affected", "versionType": "git" }, { "version": "a770f6f28b1a9287189f3dc8333eb694d9a2f0ab", "lessThan": "f33ecb89d352348ed5e625f6747ac51ede254e1b", "status": "affected", "versionType": "git" }, { "version": "a770f6f28b1a9287189f3dc8333eb694d9a2f0ab", "lessThan": "0af4711862c5b818204d40b21f0859ad51c230e9", "status": "affected", "versionType": "git" }, { "version": "a770f6f28b1a9287189f3dc8333eb694d9a2f0ab", "lessThan": "66bc868a33cf1de43f22a94acd8857e0fe33393f", "status": "affected", "versionType": "git" }, { "version": "a770f6f28b1a9287189f3dc8333eb694d9a2f0ab", "lessThan": "9f7760a2e962cbda0d096a27d394d14ad4d22928", "status": "affected", "versionType": "git" }, { "version": "a770f6f28b1a9287189f3dc8333eb694d9a2f0ab", "lessThan": "5ec42d57655c690234c14aece6dd3f209778c1d8", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/x86/kvm/mmu/mmu.c" ], "versions": [ { "version": "2.6.30", "status": "affected" }, { "version": "0", "lessThan": "2.6.30", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.183", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.152", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.104", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.45", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.9", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.30", "versionEndExcluding": "6.1.183" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.30", "versionEndExcluding": "6.6.152" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.30", "versionEndExcluding": "6.12.104" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.30", "versionEndExcluding": "6.18.45" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.30", "versionEndExcluding": "7.1.9" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.30", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/9b7984692c18b22d6d61af3f53887fca7fddb0f1" }, { "url": "https://git.kernel.org/stable/c/f33ecb89d352348ed5e625f6747ac51ede254e1b" }, { "url": "https://git.kernel.org/stable/c/0af4711862c5b818204d40b21f0859ad51c230e9" }, { "url": "https://git.kernel.org/stable/c/66bc868a33cf1de43f22a94acd8857e0fe33393f" }, { "url": "https://git.kernel.org/stable/c/9f7760a2e962cbda0d096a27d394d14ad4d22928" }, { "url": "https://git.kernel.org/stable/c/5ec42d57655c690234c14aece6dd3f209778c1d8" } ], "title": "KVM: x86/mmu: WARN and clear role.invalid when creating a child shadow page", "x_generator": { "engine": "bippy-1.2.0" } } } }