{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-21722", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-12-29T08:45:45.753Z", "datePublished": "2025-02-27T02:07:30.387Z", "dateUpdated": "2026-08-05T11:53:56.989Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:53:56.989Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnilfs2: do not force clear folio if buffer is referenced\n\nPatch series \"nilfs2: protect busy buffer heads from being force-cleared\".\n\nThis series fixes the buffer head state inconsistency issues reported by\nsyzbot that occurs when the filesystem is corrupted and falls back to\nread-only, and the associated buffer head use-after-free issue.\n\n\nThis patch (of 2):\n\nSyzbot has reported that after nilfs2 detects filesystem corruption and\nfalls back to read-only, inconsistencies in the buffer state may occur.\n\nOne of the inconsistencies is that when nilfs2 calls mark_buffer_dirty()\nto set a data or metadata buffer as dirty, but it detects that the buffer\nis not in the uptodate state:\n\n WARNING: CPU: 0 PID: 6049 at fs/buffer.c:1177 mark_buffer_dirty+0x2e5/0x520\n fs/buffer.c:1177\n ...\n Call Trace:\n \n nilfs_palloc_commit_alloc_entry+0x4b/0x160 fs/nilfs2/alloc.c:598\n nilfs_ifile_create_inode+0x1dd/0x3a0 fs/nilfs2/ifile.c:73\n nilfs_new_inode+0x254/0x830 fs/nilfs2/inode.c:344\n nilfs_mkdir+0x10d/0x340 fs/nilfs2/namei.c:218\n vfs_mkdir+0x2f9/0x4f0 fs/namei.c:4257\n do_mkdirat+0x264/0x3a0 fs/namei.c:4280\n __do_sys_mkdirat fs/namei.c:4295 [inline]\n __se_sys_mkdirat fs/namei.c:4293 [inline]\n __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4293\n do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nThe other is when nilfs_btree_propagate(), which propagates the dirty\nstate to the ancestor nodes of a b-tree that point to a dirty buffer,\ndetects that the origin buffer is not dirty, even though it should be:\n\n WARNING: CPU: 0 PID: 5245 at fs/nilfs2/btree.c:2089\n nilfs_btree_propagate+0xc79/0xdf0 fs/nilfs2/btree.c:2089\n ...\n Call Trace:\n \n nilfs_bmap_propagate+0x75/0x120 fs/nilfs2/bmap.c:345\n nilfs_collect_file_data+0x4d/0xd0 fs/nilfs2/segment.c:587\n nilfs_segctor_apply_buffers+0x184/0x340 fs/nilfs2/segment.c:1006\n nilfs_segctor_scan_file+0x28c/0xa50 fs/nilfs2/segment.c:1045\n nilfs_segctor_collect_blocks fs/nilfs2/segment.c:1216 [inline]\n nilfs_segctor_collect fs/nilfs2/segment.c:1540 [inline]\n nilfs_segctor_do_construct+0x1c28/0x6b90 fs/nilfs2/segment.c:2115\n nilfs_segctor_construct+0x181/0x6b0 fs/nilfs2/segment.c:2479\n nilfs_segctor_thread_construct fs/nilfs2/segment.c:2587 [inline]\n nilfs_segctor_thread+0x69e/0xe80 fs/nilfs2/segment.c:2701\n kthread+0x2f0/0x390 kernel/kthread.c:389\n ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147\n ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244\n \n\nBoth of these issues are caused by the callbacks that handle the\npage/folio write requests, forcibly clear various states, including the\nworking state of the buffers they hold, at unexpected times when they\ndetect read-only fallback.\n\nFix these issues by checking if the buffer is referenced before clearing\nthe page/folio state, and skipping the clear if it is." } ], "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 only through local VFS activity on a mounted nilfs2 volume — write/mkdir/fsync/sync syscalls plus kernel writeback on that mount. There is no network consumer of fs/nilfs2/page.c.\nAC:L - The attacker supplies the corrupted image that makes the read-only fallback deterministic, and drives both sides of the race themselves (sync/fsync or memory pressure to force writeback, concurrently with a mkdir/write loop holding buffer references); syzbot reproduced it reliably and the fix carries a Tested-by.\nPR:L - Once the volume is mounted — automounted removable media, a shared multi-user nilfs2 mount, or a loop image — an ordinary unprivileged user reaches the force-clear through plain VFS syscalls, with no capability check anywhere on the path to nilfs_clear_folio_dirty().\nUI:N - With the filesystem already mounted (udisks2 automount or an existing shared mount), the attacker triggers corruption detection, writeback, and the concurrent buffer access entirely on their own; no victim action is required.\nS:U - The corruption occurs in kernel buffer-head and page-cache structures on the same host under the same security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - Clearing BH_Dirty removes the buffer_busy() protection so try_to_free_buffers() frees the bh ring while nilfs_lookup_dirty_node_buffers() is still dereferencing it, giving a use-after-free read of reallocated slab contents; force-clearing BH_Uptodate/folio uptodate additionally lets stale page-cache data be treated as valid.\nI:H - The same UAF window has the segment constructor perform get_bh() and list_add_tail() into freed buffer_head memory — an attacker-groomable write primitive — and the force-clear silently discards in-flight ifile/DAT metadata updates and drops block mappings, corrupting on-disk filesystem state.\nA:H - The bug produces kernel WARNs in mark_buffer_dirty() and nilfs_btree_propagate() (panic with panic_on_warn), oopses from the use-after-free, and leaves the segment-constructor kthread walking a corrupted buffer list, hanging all further filesystem activity." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/nilfs2/page.c" ], "versions": [ { "version": "8c26c4e2694a163d525976e804d81cd955bbb40c", "lessThan": "7d0544bacc11d6aa26ecd7debf9353193c7a3328", "status": "affected", "versionType": "git" }, { "version": "8c26c4e2694a163d525976e804d81cd955bbb40c", "lessThan": "4d042811c72f71be7c14726db2c72b67025a7cb5", "status": "affected", "versionType": "git" }, { "version": "8c26c4e2694a163d525976e804d81cd955bbb40c", "lessThan": "f51ff43c4c5a6c8e72d0aca89e4d5e688938412f", "status": "affected", "versionType": "git" }, { "version": "8c26c4e2694a163d525976e804d81cd955bbb40c", "lessThan": "19296737024cd220a1d6590bf4c092bca8c99497", "status": "affected", "versionType": "git" }, { "version": "8c26c4e2694a163d525976e804d81cd955bbb40c", "lessThan": "1098bb8d52419d262a3358d099a1598a920b730f", "status": "affected", "versionType": "git" }, { "version": "8c26c4e2694a163d525976e804d81cd955bbb40c", "lessThan": "557ccf5e49f1fb848a29698585bcab2e50a597ef", "status": "affected", "versionType": "git" }, { "version": "8c26c4e2694a163d525976e804d81cd955bbb40c", "lessThan": "ca76bb226bf47ff04c782cacbd299f12ddee1ec1", "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/nilfs2/page.c" ], "versions": [ { "version": "3.10", "status": "affected" }, { "version": "0", "lessThan": "3.10", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.291", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.235", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.179", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.129", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.13", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.13.2", "lessThanOrEqual": "6.13.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.14", "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": "3.10", "versionEndExcluding": "5.4.291" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.10", "versionEndExcluding": "5.10.235" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.10", "versionEndExcluding": "5.15.179" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.10", "versionEndExcluding": "6.1.129" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.10", "versionEndExcluding": "6.12.13" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.10", "versionEndExcluding": "6.13.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.10", "versionEndExcluding": "6.14" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/7d0544bacc11d6aa26ecd7debf9353193c7a3328" }, { "url": "https://git.kernel.org/stable/c/4d042811c72f71be7c14726db2c72b67025a7cb5" }, { "url": "https://git.kernel.org/stable/c/f51ff43c4c5a6c8e72d0aca89e4d5e688938412f" }, { "url": "https://git.kernel.org/stable/c/19296737024cd220a1d6590bf4c092bca8c99497" }, { "url": "https://git.kernel.org/stable/c/1098bb8d52419d262a3358d099a1598a920b730f" }, { "url": "https://git.kernel.org/stable/c/557ccf5e49f1fb848a29698585bcab2e50a597ef" }, { "url": "https://git.kernel.org/stable/c/ca76bb226bf47ff04c782cacbd299f12ddee1ec1" } ], "title": "nilfs2: do not force clear folio if buffer is referenced", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "cvssV3_1": { "scope": "UNCHANGED", "version": "3.1", "baseScore": 7.8, "attackVector": "LOCAL", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH" } }, { "other": { "type": "ssvc", "content": { "id": "CVE-2025-21722", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2025-02-27T18:14:37.739187Z" } } } ], "problemTypes": [ { "descriptions": [ { "lang": "en", "type": "CWE", "cweId": "CWE-416", "description": "CWE-416 Use After Free" } ] } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2025-02-27T18:22:30.078Z" } }, { "title": "CVE Program Container", "references": [ { "url": "https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html" }, { "url": "https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T19:36:21.865Z" } } ] } }