{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2022-50300", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-09-15T14:18:36.812Z", "datePublished": "2025-09-15T14:45:55.896Z", "dateUpdated": "2026-08-05T08:58:04.535Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T08:58:04.535Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: fix extent map use-after-free when handling missing device in read_one_chunk\n\nStore the error code before freeing the extent_map. Though it's\nreference counted structure, in that function it's the first and last\nallocation so this would lead to a potential use-after-free.\n\nThe error can happen eg. when chunk is stored on a missing device and\nthe degraded mount option is missing.\n\nBugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=216721" } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The vulnerable path runs only during btrfs mount (open_ctree → btrfs_read_sys_array/btrfs_read_chunk_tree → read_one_chunk), reached via a local mount of a crafted or incomplete multi-device image, not via network packet processing.\nAC:L - An attacker can reliably trigger the UAF by supplying a filesystem whose chunk stripe references a missing device and ensuring mount without the non-default degraded option; the freshly allocated extent_map always has refcount 1 so free_extent_map unconditionally frees map before the PTR_ERR read.\nPR:N - btrfs lacks FS_USERNS_MOUNT so the attacker need not hold privileges on the victim host; crafting and delivering a malicious image (USB, download, shared disk) is sufficient, matching other mount-time filesystem UAF scores.\nUI:R - Exploitation requires a user or administrator to mount the attacker-controlled btrfs image, which is the necessary interaction that enters open_ctree and reaches read_one_chunk.\nS:U - Impact is confined to kernel memory in the host's btrfs mount path; this is standard kernel memory corruption without crossing a VM, IOMMU, or other security authority boundary.\nC:H - This is a genuine use-after-free of the kmalloc'd map_lookup and extent_map objects; per CVSS kernel guidance a UAF enables reclaim and disclosure of freed object contents for arbitrary kernel memory read.\nI:H - Use-after-free of heap objects during mount enables heap grooming and write/control-flow primitives once the freed map_lookup/extent_map slabs are reused, so integrity impact is High.\nA:H - The UAF on freed map_lookup memory can cause kernel oops/panic (including via inconsistent mount continuation if a reused object yields a misleading return code), so availability impact is High." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/btrfs/volumes.c" ], "versions": [ { "version": "adfb69af7d8cb6a3958f75aad1ef4bc96891d116", "lessThan": "b8e7ed42bc3ca0d0e4191ee394d34962d3624c22", "status": "affected", "versionType": "git" }, { "version": "adfb69af7d8cb6a3958f75aad1ef4bc96891d116", "lessThan": "fce3713197ebba239e1c7e02174ed216ea1ee014", "status": "affected", "versionType": "git" }, { "version": "adfb69af7d8cb6a3958f75aad1ef4bc96891d116", "lessThan": "169a4cf46882974d4db6d85eb623ec898e51bbc0", "status": "affected", "versionType": "git" }, { "version": "adfb69af7d8cb6a3958f75aad1ef4bc96891d116", "lessThan": "1742e1c90c3da344f3bb9b1f1309b3f47482756a", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/btrfs/volumes.c" ], "versions": [ { "version": "4.15", "status": "affected" }, { "version": "0", "lessThan": "4.15", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.87", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.0.18", "lessThanOrEqual": "6.0.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.4", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.2", "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": "4.15", "versionEndExcluding": "5.15.87" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.15", "versionEndExcluding": "6.0.18" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.15", "versionEndExcluding": "6.1.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.15", "versionEndExcluding": "6.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/b8e7ed42bc3ca0d0e4191ee394d34962d3624c22" }, { "url": "https://git.kernel.org/stable/c/fce3713197ebba239e1c7e02174ed216ea1ee014" }, { "url": "https://git.kernel.org/stable/c/169a4cf46882974d4db6d85eb623ec898e51bbc0" }, { "url": "https://git.kernel.org/stable/c/1742e1c90c3da344f3bb9b1f1309b3f47482756a" } ], "title": "btrfs: fix extent map use-after-free when handling missing device in read_one_chunk", "x_generator": { "engine": "bippy-1.2.0" } } } }