{"id":"CVE-2026-31553","state":"PUBLISHED","title":"KVM: arm64: Fix the descriptor address in __kvm_at_swap_desc()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: arm64: Fix the descriptor address in __kvm_at_swap_desc()\n\nUsing \"(u64 __user *)hva + offset\" to get the virtual addresses of S1/S2\ndescriptors looks really wrong, if offset is not zero. What we want to get\nfor swapping is hva + offset, not hva + offset*8. ;-)\n\nFix it.","publishedAt":"2026-04-24T14:35:37.828Z","updatedAt":"2026-08-05T12:23:27.579Z","severity":{"score":8.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"f6927b41d57390c597a126063e2e518911976878","status":"affected","lessThan":"4307e05e568782fc92eff651b09ee5dee88a058d","versionType":"git"},{"version":"f6927b41d57390c597a126063e2e518911976878","status":"affected","lessThan":"0496acc42fb51eee040b5170cec05cec41385540","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/arm64/kvm/at.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.19","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.19","versionType":"semver"},{"version":"6.19.11","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/arm64/kvm/at.c"]}],"references":["https://git.kernel.org/stable/c/4307e05e568782fc92eff651b09ee5dee88a058d","https://git.kernel.org/stable/c/0496acc42fb51eee040b5170cec05cec41385540"],"weaknesses":[],"ingestedAt":"2026-10-29T20:11:40.391Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/31xxx/CVE-2026-31553.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-31553","state":"PUBLISHED","datePublished":"2026-04-24T14:35:37.828Z","dateUpdated":"2026-08-05T12:23:27.579Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-03-09T15:48:24.115Z"},"containers":{"cna":{"title":"KVM: arm64: Fix the descriptor address in __kvm_at_swap_desc()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: arm64: Fix the descriptor address in __kvm_at_swap_desc()\n\nUsing \"(u64 __user *)hva + offset\" to get the virtual addresses of S1/S2\ndescriptors looks really wrong, if offset is not zero. What we want to get\nfor swapping is hva + offset, not hva + offset*8. ;-)\n\nFix it."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"f6927b41d57390c597a126063e2e518911976878","status":"affected","lessThan":"4307e05e568782fc92eff651b09ee5dee88a058d","versionType":"git"},{"version":"f6927b41d57390c597a126063e2e518911976878","status":"affected","lessThan":"0496acc42fb51eee040b5170cec05cec41385540","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/arm64/kvm/at.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.19","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.19","versionType":"semver"},{"version":"6.19.11","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/arm64/kvm/at.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/4307e05e568782fc92eff651b09ee5dee88a058d"},{"url":"https://git.kernel.org/stable/c/0496acc42fb51eee040b5170cec05cec41385540"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","baseScore":8.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The vulnerable path is reached by local execution of a KVM vCPU that traps arm64 AT instructions through KVM_RUN. It is not reachable by network packets or physical input.\nAC:L - The attacker can control the guest/nested page-table layout, enable hardware Access Flag management, choose a nonzero descriptor offset, and execute the trapping AT instruction. No race or external condition is required.\nPR:L - Exploitation requires control of guest or VM execution state, such as a tenant/guest operator able to run a nested-virtualization-capable VM, but not host administrator privileges. Given uncertainty, this is scored as low rather than high privilege.\nUI:N - No victim action is required once the attacker can run the malicious guest code. The trigger is a direct guest instruction/emulation path.\nS:C - This is a KVM guest-triggered bug in host-side emulation, so a plausible exploit crosses the VM isolation boundary. Corruption can affect memory in the host VMM/VM backing context rather than only the guest instruction stream.\nC:H - The incorrect pointer arithmetic creates guest-controlled memory corruption in the host userspace address used for VM memory, which can be leveraged as part of a VM escape. Per the overestimation rule, this is treated as high confidentiality impact.\nI:H - The CAS targets the wrong address and can write an attacker-influenced descriptor value outside the intended page-table entry. This is a memory corruption primitive with plausible control-flow or data integrity consequences in the VMM/VM boundary context.\nA:H - Repeated triggering can corrupt translation descriptors or adjacent VM/VMM memory and can reliably break guest execution or the VMM handling path. Kernel/KVM memory-corruption paths are scored as high availability impact."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:23:27.579Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.19","versionEndExcluding":"6.19.11"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.19","versionEndExcluding":"7.0"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}