{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2021-47221", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-04-10T18:59:19.529Z", "datePublished": "2024-05-21T14:19:27.553Z", "dateUpdated": "2026-05-11T13:50:18.334Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-05-11T13:50:18.334Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/slub: actually fix freelist pointer vs redzoning\n\nIt turns out that SLUB redzoning (\"slub_debug=Z\") checks from\ns->object_size rather than from s->inuse (which is normally bumped to\nmake room for the freelist pointer), so a cache created with an object\nsize less than 24 would have the freelist pointer written beyond\ns->object_size, causing the redzone to be corrupted by the freelist\npointer. This was very visible with \"slub_debug=ZF\":\n\n BUG test (Tainted: G B ): Right Redzone overwritten\n -----------------------------------------------------------------------------\n\n INFO: 0xffff957ead1c05de-0xffff957ead1c05df @offset=1502. First byte 0x1a instead of 0xbb\n INFO: Slab 0xffffef3950b47000 objects=170 used=170 fp=0x0000000000000000 flags=0x8000000000000200\n INFO: Object 0xffff957ead1c05d8 @offset=1496 fp=0xffff957ead1c0620\n\n Redzone (____ptrval____): bb bb bb bb bb bb bb bb ........\n Object (____ptrval____): 00 00 00 00 00 f6 f4 a5 ........\n Redzone (____ptrval____): 40 1d e8 1a aa @....\n Padding (____ptrval____): 00 00 00 00 00 00 00 00 ........\n\nAdjust the offset to stay within s->object_size.\n\n(Note that no caches of in this size range are known to exist in the\nkernel currently.)" } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "mm/slub.c" ], "versions": [ { "version": "89b83f282d8ba380cf2124f88106c57df49c538c", "lessThan": "f6ed2357541612a13a5841b3af4dc32ed984a25f", "status": "affected", "versionType": "git" }, { "version": "89b83f282d8ba380cf2124f88106c57df49c538c", "lessThan": "ce6e8bee7a3883e8008b30f5887dbb426aac6a35", "status": "affected", "versionType": "git" }, { "version": "89b83f282d8ba380cf2124f88106c57df49c538c", "lessThan": "e41a49fadbc80b60b48d3c095d9e2ee7ef7c9a8e", "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/slub.c" ], "versions": [ { "version": "5.7", "status": "affected" }, { "version": "0", "lessThan": "5.7", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.46", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.12.13", "lessThanOrEqual": "5.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.13", "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": "5.10.46" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.7", "versionEndExcluding": "5.12.13" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.7", "versionEndExcluding": "5.13" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/f6ed2357541612a13a5841b3af4dc32ed984a25f" }, { "url": "https://git.kernel.org/stable/c/ce6e8bee7a3883e8008b30f5887dbb426aac6a35" }, { "url": "https://git.kernel.org/stable/c/e41a49fadbc80b60b48d3c095d9e2ee7ef7c9a8e" } ], "title": "mm/slub: actually fix freelist pointer vs redzoning", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "timestamp": "2024-06-17T17:38:07.843861Z", "id": "CVE-2021-47221", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "role": "CISA Coordinator", "version": "2.0.3" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-06-17T17:40:09.755Z" } }, { "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-04T05:32:07.427Z" }, "title": "CVE Program Container", "references": [ { "url": "https://git.kernel.org/stable/c/f6ed2357541612a13a5841b3af4dc32ed984a25f", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/ce6e8bee7a3883e8008b30f5887dbb426aac6a35", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/e41a49fadbc80b60b48d3c095d9e2ee7ef7c9a8e", "tags": [ "x_transferred" ] } ] } ] } }