{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-21811", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-12-29T08:45:45.772Z", "datePublished": "2025-02-27T20:01:02.256Z", "dateUpdated": "2026-08-05T11:54:38.930Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:54:38.930Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnilfs2: protect access to buffers with no active references\n\nnilfs_lookup_dirty_data_buffers(), which iterates through the buffers\nattached to dirty data folios/pages, accesses the attached buffers without\nlocking the folios/pages.\n\nFor data cache, nilfs_clear_folio_dirty() may be called asynchronously\nwhen the file system degenerates to read only, so\nnilfs_lookup_dirty_data_buffers() still has the potential to cause use\nafter free issues when buffers lose the protection of their dirty state\nmidway due to this asynchronous clearing and are unintentionally freed by\ntry_to_free_buffers().\n\nEliminate this race issue by adjusting the lock section in this function." } ], "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 - nilfs2 is a block-device filesystem; the race is driven through local file I/O (write/fsync creating dirty data folios) plus local page-cache pressure on a mounted volume. No network reachability exists, so this is a local attack vector.\nAC:L - The attacker controls both sides of the race — a crafted nilfs2 image deterministically forces the errors=remount-ro fallback that triggers the asynchronous nilfs_clear_folio_dirty(), while write/fsync drives the unlocked buffer walk and posix_fadvise(DONTNEED)/memory pressure drives try_to_free_buffers(). The race window can be retried indefinitely.\nPR:L - An unprivileged local user with write access to a nilfs2 mount that has degraded to read-only can drive both the dirty-buffer collection path and the buffer-freeing path with no capabilities; on desktop/kiosk systems udisks2 auto-mount also lets an unprivileged user get a crafted image mounted.\nUI:N - On an already-mounted nilfs2 volume no victim action is needed — the attacker's own writes, fsync, and cache-eviction calls trigger the race against the always-running segment constructor thread.\nS:U - The use-after-free corrupts kernel slab memory within the same kernel security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - The freed buffer_head is read (b_state, b_this_page, b_data, b_page) and queued for actual segment write-out, so contents of a reallocated slab object can be leaked into the on-disk log and read back; a UAF of this shape yields an arbitrary-read primitive.\nI:H - The loop performs get_bh() (atomic_inc) and list_add_tail(&bh->b_assoc_buffers, listp) into the freed bh_cachep object, writing attacker-influenceable pointers into whatever object now occupies that slot — a controllable write primitive suitable for heap grooming and control-flow hijack.\nA:H - Walking and linking freed buffer_heads reliably produces list corruption, slab corruption, and kernel oops/panic, taking the system down." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/nilfs2/segment.c" ], "versions": [ { "version": "8c26c4e2694a163d525976e804d81cd955bbb40c", "lessThan": "e1fc4a90a90ea8514246c45435662531975937d9", "status": "affected", "versionType": "git" }, { "version": "8c26c4e2694a163d525976e804d81cd955bbb40c", "lessThan": "72cf688d0ce7e642b12ddc9b2a42524737ec1b4a", "status": "affected", "versionType": "git" }, { "version": "8c26c4e2694a163d525976e804d81cd955bbb40c", "lessThan": "d8ff250e085a4c4cdda4ad1cdd234ed110393143", "status": "affected", "versionType": "git" }, { "version": "8c26c4e2694a163d525976e804d81cd955bbb40c", "lessThan": "58c27fa7a610b6e8d44e6220e7dbddfbaccaf439", "status": "affected", "versionType": "git" }, { "version": "8c26c4e2694a163d525976e804d81cd955bbb40c", "lessThan": "8e1b9201c9a24638cf09c6e1c9f224157328010b", "status": "affected", "versionType": "git" }, { "version": "8c26c4e2694a163d525976e804d81cd955bbb40c", "lessThan": "4b08d23d7d1917bef4fbee8ad81372f49b006656", "status": "affected", "versionType": "git" }, { "version": "8c26c4e2694a163d525976e804d81cd955bbb40c", "lessThan": "c437dfac9f7a5a46ac2a5e6d6acd3059e9f68188", "status": "affected", "versionType": "git" }, { "version": "8c26c4e2694a163d525976e804d81cd955bbb40c", "lessThan": "367a9bffabe08c04f6d725032cce3d891b2b9e1a", "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/segment.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": "6.6.76", "lessThanOrEqual": "6.6.*", "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": "6.6.76" }, { "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/e1fc4a90a90ea8514246c45435662531975937d9" }, { "url": "https://git.kernel.org/stable/c/72cf688d0ce7e642b12ddc9b2a42524737ec1b4a" }, { "url": "https://git.kernel.org/stable/c/d8ff250e085a4c4cdda4ad1cdd234ed110393143" }, { "url": "https://git.kernel.org/stable/c/58c27fa7a610b6e8d44e6220e7dbddfbaccaf439" }, { "url": "https://git.kernel.org/stable/c/8e1b9201c9a24638cf09c6e1c9f224157328010b" }, { "url": "https://git.kernel.org/stable/c/4b08d23d7d1917bef4fbee8ad81372f49b006656" }, { "url": "https://git.kernel.org/stable/c/c437dfac9f7a5a46ac2a5e6d6acd3059e9f68188" }, { "url": "https://git.kernel.org/stable/c/367a9bffabe08c04f6d725032cce3d891b2b9e1a" } ], "title": "nilfs2: protect access to buffers with no active references", "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-2025-21811", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2025-03-04T18:01:20.629324Z" } } } ], "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": "2025-03-04T18:07:17.439Z" } }, { "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": "2025-11-03T20:59:47.268Z" } } ] } }