{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2024-43832", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-08-17T09:11:59.273Z", "datePublished": "2024-08-17T09:21:50.230Z", "dateUpdated": "2026-08-05T11:36:41.646Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:36:41.646Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ns390/uv: Don't call folio_wait_writeback() without a folio reference\n\nfolio_wait_writeback() requires that no spinlocks are held and that\na folio reference is held, as documented. After we dropped the PTL, the\nfolio could get freed concurrently. So grab a temporary reference." } ], "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 - The vulnerable code is reached through the s390 KVM protected-virtualization path — the `KVM_S390_PV_COMMAND`/`KVM_RUN` ioctls on /dev/kvm and the host's secure/non-secure storage-access fault handler running in the vCPU thread. No network input is involved, so local system access is required.\nAC:L - The attacker controls both sides of the race: it forces `rc == -EAGAIN` deterministically (start writeback on the file/shmem-backed guest page so `make_folio_secure()` returns -EAGAIN, or hold the folio lock) while a second thread `MADV_DONTNEED`s/munmaps that guest memory to free the folio in the window after the PTL and mmap_read_lock are dropped. The attempt is cheap and infinitely retryable.\nPR:L - Only an unprivileged local user with access to /dev/kvm (commonly mode 0666 or the `kvm` group on distros) is needed to create a VM, enable protected virtualization, and drive the unpack/secure-storage paths; no CAP_SYS_ADMIN or real root is required. A malicious guest reaching `handle_pv_uvc()` with a guest-controlled address is likewise not a privileged host actor.\nUI:N - The entire sequence is performed by the attacker's own threads via ioctls and memory-management syscalls on its own VM. No victim action of any kind is needed.\nS:U - The attacking process and the corrupted resources (host kernel MM metadata) live under the same security authority — this is a local host-kernel compromise, not an IOMMU or hypervisor-boundary escape granting control of a separate authority.\nC:H - This is a use-after-free on a folio whose `struct page` has been reallocated to an unrelated owner; the code reads that stale state and the resulting page-state corruption is leverageable for disclosure of memory belonging to other subsystems. Per UAF scoring guidance, confidentiality impact is High.\nI:H - `folio_wait_bit_common()` performs an atomic `set_bit(PG_waiters, &folio->flags)` write into a `struct page` that now describes someone else's allocation, corrupting core MM metadata for a page the attacker can influence the reuse of via heap/page grooming — a write primitive into kernel state, hence High.\nA:H - A stale `PG_writeback` bit in the reused page makes `folio_wait_bit()` sleep TASK_UNINTERRUPTIBLE with no waker, producing an unkillable task and hung-task panics, while a spurious `PG_waiters` trips `bad_page()` (\"BUG: Bad page state\") since `PAGE_FLAGS_CHECK_AT_PREP` covers the whole flags mask. Either outcome is a full kernel-level denial of service." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/s390/kernel/uv.c" ], "versions": [ { "version": "214d9bbcd3a67230b932f6cea83c078ab34d9e70", "lessThan": "1a1eb2f3fc453dcd52726d13e863938561489cb7", "status": "affected", "versionType": "git" }, { "version": "214d9bbcd3a67230b932f6cea83c078ab34d9e70", "lessThan": "8736604ef53359a718c246087cd21dcec232d2fb", "status": "affected", "versionType": "git" }, { "version": "214d9bbcd3a67230b932f6cea83c078ab34d9e70", "lessThan": "b21aba72aadd94bdac275deab021fc84d6c72b16", "status": "affected", "versionType": "git" }, { "version": "214d9bbcd3a67230b932f6cea83c078ab34d9e70", "lessThan": "3f29f6537f54d74e64bac0a390fb2e26da25800d", "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/kernel/uv.c" ], "versions": [ { "version": "5.7", "status": "affected" }, { "version": "0", "lessThan": "5.7", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.103", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.44", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.10.3", "lessThanOrEqual": "6.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.11", "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": "5.7", "versionEndExcluding": "6.1.103" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.7", "versionEndExcluding": "6.6.44" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.7", "versionEndExcluding": "6.10.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.7", "versionEndExcluding": "6.11" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/1a1eb2f3fc453dcd52726d13e863938561489cb7" }, { "url": "https://git.kernel.org/stable/c/8736604ef53359a718c246087cd21dcec232d2fb" }, { "url": "https://git.kernel.org/stable/c/b21aba72aadd94bdac275deab021fc84d6c72b16" }, { "url": "https://git.kernel.org/stable/c/3f29f6537f54d74e64bac0a390fb2e26da25800d" } ], "title": "s390/uv: Don't call folio_wait_writeback() without a folio reference", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2024-43832", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "version": "2.0.3", "timestamp": "2024-09-10T16:08:24.816195Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-09-12T17:33:07.778Z" } }, { "title": "CVE Program Container", "references": [ { "url": "https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T22:05:16.929Z" } } ] } }