{"api_version":"1","generated_at":"2026-10-23T12:14:01+00:00","cve":"CVE-2026-98468","urls":{"html":"https://cve.report/CVE-2026-98468","api":"https://cve.report/api/cve/CVE-2026-98468.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-98468","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-98468"},"summary":{"title":"KVM: arm64: Fix spurious warning for benign stage 2 teardown race","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: arm64: Fix spurious warning for benign stage 2 teardown race\n\nkvmtool was used to establish an L1 guest with 8 CPUs and 8 GiB of RAM, an\nL2 guest with 4 CPUs and 4 GiB of RAM and an L3 guest with 2 CPUs and 2 GiB\nof RAM, all of which was then exited.\n\nUnder memory pressure in the L0 host warnings were observed due to\nmigration triggered by compaction:\n\nWARNING: arch/arm64/kvm/mmu.c:336 at __unmap_stage2_range+0x64/0x80,\nCPU#5: kcompactd0/66\n\nWhich was, in turn, triggered by an MMU notifier for the host invalidation:\n\nmmu_notifier_invalidate_range_start()\n  -> ... -> kvm_mmu_notifier_invalidate_range_start()\n    -> kvm_mmu_unmap_gfn_range()\n      -> kvm_unmap_gfn_range()\n        -> kvm_nested_s2_unmap()\n          -> kvm_stage2_unmap_range()\n            -> __unmap_stage2_range()\n               -> stage2_apply_range()\n       \t       <- -EINVAL, triggering a WARN_ON()\n\nRacing with L0's teardown of stage 2 page tables:\n\nexit_mm()\n  -> mmput()\n    -> __mmput()\n      -> exit_mmap()\n        -> mmu_notifier_release()\n\t  -> ... -> kvm_mmu_notifier_release()\n            -> kvm_flush_shadow_all()\n              -> kvm_arch_flush_shadow_all()\n\t        -> kvm_free_stage2_pgd()\n\t\t  -> [ acquire kvm->mmu_lock for write ]\n\t\t  -> mmu->pgt = NULL [ among other tasks ]\n\t\t  -> [ release kvm->mmu_lock for write ]\n\nIt turns out there is a benign race resulting in a spurious warning:\n\n\tThread A - notify: migration   | Thread B - notify: release\n\t-------------------------------|---------------------------------\n\t< kvm->mmu_lock held >         |\n\tstage2_apply_range()           |\n\t  get mmu->pgt, check !NULL    |\n\t  ...                          | kvm_arch_flush_shadow_all()\n\t  cond_resched_rwlock_write(); |   < contend, sleep kvm->mmu_lock >\n\t< drop kvm->mmu_lock >         |   < acquire kvm->mmu_lock>\n                                       |   ...\n\t\t\t\t       |   kvm_free_stage2_pgd()\n                                       |     mmu->pgt = NULL\n\t\t\t\t       |   < invalidate MMU >\n\t\t\t\t       |   ...\n\t\t\t\t       |   < release kvm->mmu_lock >\n\t[ scheduled ]\t\t       |\n\tstage2_apply_range()           |\n\t  < loop to next >             |\n\t  get, mmu->pgt, check !NULL   |\n\t  is NULL, return -EINVAL      |\n        __unmap_stage2_range()         |\n\t  WARN_ON(-EINVAL) <--- entirely spurious - the race was handled\n                                 correctly.\n\nFix the spurious warning by updating stage2_apply_range() to no longer\ntreat concurrent PGT teardown on lock release as an error - whether the\nwalker is tearing down page tables or doing something else this is a\nlegitimate reason to abort the operation without error.\n\nThis keeps the warning in place for all other circumstances.\n\nIn practice only __unmap_stage2_range() actually does anything with the\nerror so this only impacts that.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-10-18 16:16:57","updated_at":"2026-10-19 10:18:56"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/c23ed110d27ba99cf3a881986514f79aacedf476","name":"https://git.kernel.org/stable/c/c23ed110d27ba99cf3a881986514f79aacedf476","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/330346dda3bf5f8a3b06723024f7d906326270cf","name":"https://git.kernel.org/stable/c/330346dda3bf5f8a3b06723024f7d906326270cf","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/38b70fc453c3112f1a62583b89903ae41116cc27","name":"https://git.kernel.org/stable/c/38b70fc453c3112f1a62583b89903ae41116cc27","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/f44a92633136b409ebb9b7036fceb7e11de60a20","name":"https://git.kernel.org/stable/c/f44a92633136b409ebb9b7036fceb7e11de60a20","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-98468","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98468","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ec14c272408af43d392f65f55e66f3b94fc61921 f44a92633136b409ebb9b7036fceb7e11de60a20 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ec14c272408af43d392f65f55e66f3b94fc61921 c23ed110d27ba99cf3a881986514f79aacedf476 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ec14c272408af43d392f65f55e66f3b94fc61921 330346dda3bf5f8a3b06723024f7d906326270cf git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ec14c272408af43d392f65f55e66f3b94fc61921 38b70fc453c3112f1a62583b89903ae41116cc27 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.11","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.11 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.112 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.55 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.9 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["arch/arm64/kvm/mmu.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"f44a92633136b409ebb9b7036fceb7e11de60a20","status":"affected","version":"ec14c272408af43d392f65f55e66f3b94fc61921","versionType":"git"},{"lessThan":"c23ed110d27ba99cf3a881986514f79aacedf476","status":"affected","version":"ec14c272408af43d392f65f55e66f3b94fc61921","versionType":"git"},{"lessThan":"330346dda3bf5f8a3b06723024f7d906326270cf","status":"affected","version":"ec14c272408af43d392f65f55e66f3b94fc61921","versionType":"git"},{"lessThan":"38b70fc453c3112f1a62583b89903ae41116cc27","status":"affected","version":"ec14c272408af43d392f65f55e66f3b94fc61921","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["arch/arm64/kvm/mmu.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"6.11"},{"lessThan":"6.11","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.112","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.55","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.9","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.112","versionStartIncluding":"6.11","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.55","versionStartIncluding":"6.11","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.9","versionStartIncluding":"6.11","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3","versionStartIncluding":"6.11","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: arm64: Fix spurious warning for benign stage 2 teardown race\n\nkvmtool was used to establish an L1 guest with 8 CPUs and 8 GiB of RAM, an\nL2 guest with 4 CPUs and 4 GiB of RAM and an L3 guest with 2 CPUs and 2 GiB\nof RAM, all of which was then exited.\n\nUnder memory pressure in the L0 host warnings were observed due to\nmigration triggered by compaction:\n\nWARNING: arch/arm64/kvm/mmu.c:336 at __unmap_stage2_range+0x64/0x80,\nCPU#5: kcompactd0/66\n\nWhich was, in turn, triggered by an MMU notifier for the host invalidation:\n\nmmu_notifier_invalidate_range_start()\n  -> ... -> kvm_mmu_notifier_invalidate_range_start()\n    -> kvm_mmu_unmap_gfn_range()\n      -> kvm_unmap_gfn_range()\n        -> kvm_nested_s2_unmap()\n          -> kvm_stage2_unmap_range()\n            -> __unmap_stage2_range()\n               -> stage2_apply_range()\n       \t       <- -EINVAL, triggering a WARN_ON()\n\nRacing with L0's teardown of stage 2 page tables:\n\nexit_mm()\n  -> mmput()\n    -> __mmput()\n      -> exit_mmap()\n        -> mmu_notifier_release()\n\t  -> ... -> kvm_mmu_notifier_release()\n            -> kvm_flush_shadow_all()\n              -> kvm_arch_flush_shadow_all()\n\t        -> kvm_free_stage2_pgd()\n\t\t  -> [ acquire kvm->mmu_lock for write ]\n\t\t  -> mmu->pgt = NULL [ among other tasks ]\n\t\t  -> [ release kvm->mmu_lock for write ]\n\nIt turns out there is a benign race resulting in a spurious warning:\n\n\tThread A - notify: migration   | Thread B - notify: release\n\t-------------------------------|---------------------------------\n\t< kvm->mmu_lock held >         |\n\tstage2_apply_range()           |\n\t  get mmu->pgt, check !NULL    |\n\t  ...                          | kvm_arch_flush_shadow_all()\n\t  cond_resched_rwlock_write(); |   < contend, sleep kvm->mmu_lock >\n\t< drop kvm->mmu_lock >         |   < acquire kvm->mmu_lock>\n                                       |   ...\n\t\t\t\t       |   kvm_free_stage2_pgd()\n                                       |     mmu->pgt = NULL\n\t\t\t\t       |   < invalidate MMU >\n\t\t\t\t       |   ...\n\t\t\t\t       |   < release kvm->mmu_lock >\n\t[ scheduled ]\t\t       |\n\tstage2_apply_range()           |\n\t  < loop to next >             |\n\t  get, mmu->pgt, check !NULL   |\n\t  is NULL, return -EINVAL      |\n        __unmap_stage2_range()         |\n\t  WARN_ON(-EINVAL) <--- entirely spurious - the race was handled\n                                 correctly.\n\nFix the spurious warning by updating stage2_apply_range() to no longer\ntreat concurrent PGT teardown on lock release as an error - whether the\nwalker is tearing down page tables or doing something else this is a\nlegitimate reason to abort the operation without error.\n\nThis keeps the warning in place for all other circumstances.\n\nIn practice only __unmap_stage2_range() actually does anything with the\nerror so this only impacts that."}],"providerMetadata":{"dateUpdated":"2026-10-19T09:20:06.341Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/f44a92633136b409ebb9b7036fceb7e11de60a20"},{"url":"https://git.kernel.org/stable/c/c23ed110d27ba99cf3a881986514f79aacedf476"},{"url":"https://git.kernel.org/stable/c/330346dda3bf5f8a3b06723024f7d906326270cf"},{"url":"https://git.kernel.org/stable/c/38b70fc453c3112f1a62583b89903ae41116cc27"}],"title":"KVM: arm64: Fix spurious warning for benign stage 2 teardown race","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-98468","datePublished":"2026-10-18T15:15:20.882Z","dateReserved":"2026-09-25T10:25:14.351Z","dateUpdated":"2026-10-19T09:20:06.341Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-10-18 16:16:57","lastModifiedDate":"2026-10-19 10:18:56","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"98468","Ordinal":"1","Title":"KVM: arm64: Fix spurious warning for benign stage 2 teardown rac","CVE":"CVE-2026-98468","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"98468","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: arm64: Fix spurious warning for benign stage 2 teardown race\n\nkvmtool was used to establish an L1 guest with 8 CPUs and 8 GiB of RAM, an\nL2 guest with 4 CPUs and 4 GiB of RAM and an L3 guest with 2 CPUs and 2 GiB\nof RAM, all of which was then exited.\n\nUnder memory pressure in the L0 host warnings were observed due to\nmigration triggered by compaction:\n\nWARNING: arch/arm64/kvm/mmu.c:336 at __unmap_stage2_range+0x64/0x80,\nCPU#5: kcompactd0/66\n\nWhich was, in turn, triggered by an MMU notifier for the host invalidation:\n\nmmu_notifier_invalidate_range_start()\n  -> ... -> kvm_mmu_notifier_invalidate_range_start()\n    -> kvm_mmu_unmap_gfn_range()\n      -> kvm_unmap_gfn_range()\n        -> kvm_nested_s2_unmap()\n          -> kvm_stage2_unmap_range()\n            -> __unmap_stage2_range()\n               -> stage2_apply_range()\n       \t       <- -EINVAL, triggering a WARN_ON()\n\nRacing with L0's teardown of stage 2 page tables:\n\nexit_mm()\n  -> mmput()\n    -> __mmput()\n      -> exit_mmap()\n        -> mmu_notifier_release()\n\t  -> ... -> kvm_mmu_notifier_release()\n            -> kvm_flush_shadow_all()\n              -> kvm_arch_flush_shadow_all()\n\t        -> kvm_free_stage2_pgd()\n\t\t  -> [ acquire kvm->mmu_lock for write ]\n\t\t  -> mmu->pgt = NULL [ among other tasks ]\n\t\t  -> [ release kvm->mmu_lock for write ]\n\nIt turns out there is a benign race resulting in a spurious warning:\n\n\tThread A - notify: migration   | Thread B - notify: release\n\t-------------------------------|---------------------------------\n\t< kvm->mmu_lock held >         |\n\tstage2_apply_range()           |\n\t  get mmu->pgt, check !NULL    |\n\t  ...                          | kvm_arch_flush_shadow_all()\n\t  cond_resched_rwlock_write(); |   < contend, sleep kvm->mmu_lock >\n\t< drop kvm->mmu_lock >         |   < acquire kvm->mmu_lock>\n                                       |   ...\n\t\t\t\t       |   kvm_free_stage2_pgd()\n                                       |     mmu->pgt = NULL\n\t\t\t\t       |   < invalidate MMU >\n\t\t\t\t       |   ...\n\t\t\t\t       |   < release kvm->mmu_lock >\n\t[ scheduled ]\t\t       |\n\tstage2_apply_range()           |\n\t  < loop to next >             |\n\t  get, mmu->pgt, check !NULL   |\n\t  is NULL, return -EINVAL      |\n        __unmap_stage2_range()         |\n\t  WARN_ON(-EINVAL) <--- entirely spurious - the race was handled\n                                 correctly.\n\nFix the spurious warning by updating stage2_apply_range() to no longer\ntreat concurrent PGT teardown on lock release as an error - whether the\nwalker is tearing down page tables or doing something else this is a\nlegitimate reason to abort the operation without error.\n\nThis keeps the warning in place for all other circumstances.\n\nIn practice only __unmap_stage2_range() actually does anything with the\nerror so this only impacts that.","Type":"Description","Title":"KVM: arm64: Fix spurious warning for benign stage 2 teardown rac"}]}}}