{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-89919","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-09-11T19:38:34.775Z","datePublished":"2026-09-16T10:32:14.013Z","dateUpdated":"2026-09-16T14:40:12.561Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-09-16T14:40:12.561Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: s390: keyop: use mmu_lock to read gmap->asce\n\nEvery other dat_* consumer in this file (kvm_s390_get_skeys,\nset_skeys, get_cmma_bits, set_cmma_bits, MEM_CLR_CMMA,\nkvm_s390_fixup_prefix, kvm_test_age_gfn, kvm_age_gfn) reads\nkvm->arch.gmap->asce *inside* the mmu_lock read-side. keyop is the only\noutlier.\n\ngmap->asce is mutated under write_lock(mmu_lock) by gmap_set_limit()\nand keyop might use a stale asce value for walking as KVM_S390_KEYOP\nand KVM_S390_VM_MEM_LIMIT_SIZE can run concurrently. This can result\nin memory corruption."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - Triggered by KVM_S390_KEYOP and KVM_SET_DEVICE_ATTR(KVM_S390_VM_MEM_LIMIT_SIZE) ioctls on a VM fd from /dev/kvm. Not reachable via network packets or guest instruction emulation.\nAC:L - The attacker controls both sides of the race by issuing KEYOP and MEM_LIMIT_SIZE concurrently on a VM they created (before vCPUs exist). No victim state or other uncontrolled condition is required.\nPR:L - Regular (non-ucontrol) VM creation has no capability check; any user who can open /dev/kvm, typically via kvm-group membership, can create a VM and issue these ioctls. CAP_SYS_ADMIN is not required.\nUI:N - The attacker issues the ioctls on a VM they created; no separate user action is required.\nS:U - This is host-userspace-to-host-kernel memory corruption via KVM ioctls, not a guest-to-host escape. MEM_LIMIT_SIZE is rejected once vCPUs exist, and guest storage-key paths already read gmap->asce under mmu_lock.\nC:H - kvm_s390_keyop snapshots gmap->asce without mmu_lock while gmap_set_limit() can free that CRST under write_lock, a page-table use-after-free. Walking reused tables, including ISKE/page_get_storage_key, can disclose kernel memory.\nI:H - SSKE walks the stale ASCE with DAT_WALK_ALLOC and writes via page_set_storage_key and pgste updates. The use-after-free of gmap tables enables writes into recycled kernel memory and storage-key changes on attacker-chosen physical pages.\nA:H - Walking freed CRST/PTE memory or spinning on PGSTE locks derived from reused pages can oops, panic, or hang the host kernel."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/s390/kvm/kvm-s390.c"],"versions":[{"version":"0ee4ddc1647b8b3b9e7a94d798a1774a764428c1","lessThan":"ae452b990e0544425f77045351c56e77158858e7","status":"affected","versionType":"git"},{"version":"0ee4ddc1647b8b3b9e7a94d798a1774a764428c1","lessThan":"da07a751efa4583385f9f0f47113549fe8871242","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/s390/kvm/kvm-s390.c"],"versions":[{"version":"7.0","status":"affected"},{"version":"0","lessThan":"7.0","status":"unaffected","versionType":"semver"},{"version":"7.2.5","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3-rc1","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":"7.0","versionEndExcluding":"7.2.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"7.0","versionEndExcluding":"7.3-rc1"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/ae452b990e0544425f77045351c56e77158858e7"},{"url":"https://git.kernel.org/stable/c/da07a751efa4583385f9f0f47113549fe8871242"}],"title":"KVM: s390: keyop: use mmu_lock to read gmap->asce","x_generator":{"engine":"bippy-1.2.0"}}}}