{ "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": "2026-10-19T08:54:53.667Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:54:53.667Z" }, "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", "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" } ] } ] } ], "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" } } } }