{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2024-47676", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-09-30T16:00:12.938Z", "datePublished": "2024-10-21T11:53:20.482Z", "dateUpdated": "2026-08-05T11:39:22.950Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:39:22.950Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/hugetlb.c: fix UAF of vma in hugetlb fault pathway\n\nSyzbot reports a UAF in hugetlb_fault(). This happens because\nvmf_anon_prepare() could drop the per-VMA lock and allow the current VMA\nto be freed before hugetlb_vma_unlock_read() is called.\n\nWe can fix this by using a modified version of vmf_anon_prepare() that\ndoesn't release the VMA lock on failure, and then release it ourselves\nafter hugetlb_vma_unlock_read()." } ], "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 vulnerability is triggered by a page fault on a hugetlb mapping in the attacker's own address space, requiring local execution of code on the target system. There is no network-reachable path into `hugetlb_fault()`.\nAC:L - The attacker controls every side of the race — the faulting thread, the sibling thread holding `mmap_lock` for write that forces `mmap_read_trylock()` to fail, and the `munmap()` thread that frees the VMA — and can retry the fault indefinitely. Syzbot reproduced the UAF, confirming it is reliably triggerable.\nPR:L - Any unprivileged local user can create the required private hugetlb VMA via `memfd_create(MFD_HUGETLB)` or `mmap(MAP_HUGETLB|MAP_NORESERVE)` with no capability check, and the UAF path in `hugetlb_no_page()` is reached before any hugepage allocation is attempted. No CAP_* or root is needed.\nUI:N - The attacker's own threads perform the mapping, faulting, and unmapping entirely on their own; no victim action or interaction of any kind is required.\nS:U - The corruption is of a `vm_area_struct` in kernel slab memory belonging to the attacker's own mm, handled by the kernel itself. It is a standard in-kernel memory-safety issue with no crossing of a VM, IOMMU, or other security-authority boundary.\nC:H - After the VMA is freed, `hugetlb_vma_unlock_read()` reads `vma->vm_flags` and `vma->vm_private_data` from reclaimed slab memory, so an attacker who grooms the freed `vm_area_struct` can steer subsequent dereferences and leverage the UAF for kernel memory disclosure.\nI:H - The stale `vma->vm_private_data` is used as a `hugetlb_vma_lock`/`resv_map` pointer and `up_read()` performs an atomic decrement plus possible waiter-list manipulation at that attacker-influenced address, giving a controllable kernel write primitive suitable for privilege escalation via heap spraying.\nA:H - Dereferencing a freed `vm_area_struct` and operating an rwsem derived from reclaimed memory readily causes kernel oops, rwsem-state corruption, or panic, and the attacker can trigger it repeatedly at will." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "mm/hugetlb.c" ], "versions": [ { "version": "9acad7ba3e25d11f4c96df1b7312ae89e6faca5c", "lessThan": "e897d184a8dd4a4e1f39c8c495598e4d9472776c", "status": "affected", "versionType": "git" }, { "version": "9acad7ba3e25d11f4c96df1b7312ae89e6faca5c", "lessThan": "d59ebc99dee0a2687a26df94b901eb8216dbf876", "status": "affected", "versionType": "git" }, { "version": "9acad7ba3e25d11f4c96df1b7312ae89e6faca5c", "lessThan": "98b74bb4d7e96b4da5ef3126511febe55b76b807", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "mm/hugetlb.c" ], "versions": [ { "version": "6.9", "status": "affected" }, { "version": "0", "lessThan": "6.9", "status": "unaffected", "versionType": "semver" }, { "version": "6.10.13", "lessThanOrEqual": "6.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.11.2", "lessThanOrEqual": "6.11.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12", "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": "6.9", "versionEndExcluding": "6.10.13" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "6.11.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "6.12" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/e897d184a8dd4a4e1f39c8c495598e4d9472776c" }, { "url": "https://git.kernel.org/stable/c/d59ebc99dee0a2687a26df94b901eb8216dbf876" }, { "url": "https://git.kernel.org/stable/c/98b74bb4d7e96b4da5ef3126511febe55b76b807" } ], "title": "mm/hugetlb.c: fix UAF of vma in hugetlb fault pathway", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2024-47676", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "version": "2.0.3", "timestamp": "2024-10-21T13:07:59.972172Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-10-21T13:14:17.370Z" } } ] } }