{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-72170", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-09T03:40:39.910Z", "datePublished": "2026-08-15T05:53:36.332Z", "dateUpdated": "2026-08-15T05:53:36.332Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-15T05:53:36.332Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\n9p: skip nlink update in cacheless mode to fix WARN_ON\n\nv9fs_dec_count() unconditionally calls drop_nlink() on regular files,\neven when the inode's nlink is already zero. In cacheless mode the\nclient refetches inode metadata from the server (the source of truth)\non every operation, so by the time v9fs_remove() returns, the locally\ncached nlink may already reflect the post-unlink value:\n\n 1. Client initiates unlink, server processes it and sets nlink to 0\n 2. Client refetches inode metadata (nlink=0) before unlink returns\n 3. Client's v9fs_remove() completes successfully\n 4. Client calls v9fs_dec_count() which calls drop_nlink() on nlink=0\n\nThis race is easily triggered under heavy unlink workloads, such as\nstress-ng's unlink stressor, producing the following warning:\n\n WARNING: fs/inode.c:417 at drop_nlink+0x4c/0xc8\n Call trace:\n drop_nlink+0x4c/0xc8\n v9fs_remove+0x1e0/0x250 [9p]\n v9fs_vfs_unlink+0x20/0x38 [9p]\n vfs_unlink+0x13c/0x258\n ...\n\nIn cacheless mode the server is authoritative and the inode is on its\nway out, so locally adjusting nlink buys nothing. Skip v9fs_dec_count()\nentirely when neither CACHE_META nor CACHE_LOOSE is set, which both\navoids the warning and removes a class of nlink races (two concurrent\nunlinkers observing nlink > 0 and both calling drop_nlink()) that an\nnlink == 0 guard alone would only narrow rather than close."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/9p/vfs_inode.c"], "versions": [{"version": "ac89b2ef9b55924bcf922251f043ba73a32d05bb", "lessThan": "a5a682b016ef5b5384e28f6d652d47a8f8e73d37", "status": "affected", "versionType": "git"}, {"version": "ac89b2ef9b55924bcf922251f043ba73a32d05bb", "lessThan": "de79c3f3643841b8659a71958df7cf2a66bfd409", "status": "affected", "versionType": "git"}, {"version": "ac89b2ef9b55924bcf922251f043ba73a32d05bb", "lessThan": "8d610017c992de705b304d3d727a6e3a86af6149", "status": "affected", "versionType": "git"}, {"version": "ac89b2ef9b55924bcf922251f043ba73a32d05bb", "lessThan": "8faccac11e1369adddf5d80f4a45af93f13b2e1a", "status": "affected", "versionType": "git"}, {"version": "ac89b2ef9b55924bcf922251f043ba73a32d05bb", "lessThan": "574aa0b4799470ac814479f1138d19efe6262255", "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/9p/vfs_inode.c"], "versions": [{"version": "4.17", "status": "affected"}, {"version": "0", "lessThan": "4.17", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.145", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.97", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.40", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1.5", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2-rc1", "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": "4.17", "versionEndExcluding": "6.6.145"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.17", "versionEndExcluding": "6.12.97"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.17", "versionEndExcluding": "6.18.40"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.17", "versionEndExcluding": "7.1.5"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.17", "versionEndExcluding": "7.2-rc1"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/a5a682b016ef5b5384e28f6d652d47a8f8e73d37"}, {"url": "https://git.kernel.org/stable/c/de79c3f3643841b8659a71958df7cf2a66bfd409"}, {"url": "https://git.kernel.org/stable/c/8d610017c992de705b304d3d727a6e3a86af6149"}, {"url": "https://git.kernel.org/stable/c/8faccac11e1369adddf5d80f4a45af93f13b2e1a"}, {"url": "https://git.kernel.org/stable/c/574aa0b4799470ac814479f1138d19efe6262255"}], "title": "9p: skip nlink update in cacheless mode to fix WARN_ON", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["fs/9p/vfs_inode.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "a5a682b016ef5b5384e28f6d652d47a8f8e73d37", "status": "affected", "version": "ac89b2ef9b55924bcf922251f043ba73a32d05bb", "versionType": "git"}, {"lessThan": "de79c3f3643841b8659a71958df7cf2a66bfd409", "status": "affected", "version": "ac89b2ef9b55924bcf922251f043ba73a32d05bb", "versionType": "git"}, {"lessThan": "8d610017c992de705b304d3d727a6e3a86af6149", "status": "affected", "version": "ac89b2ef9b55924bcf922251f043ba73a32d05bb", "versionType": "git"}, {"lessThan": "8faccac11e1369adddf5d80f4a45af93f13b2e1a", "status": "affected", "version": "ac89b2ef9b55924bcf922251f043ba73a32d05bb", "versionType": "git"}, {"lessThan": "574aa0b4799470ac814479f1138d19efe6262255", "status": "affected", "version": "ac89b2ef9b55924bcf922251f043ba73a32d05bb", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["fs/9p/vfs_inode.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "4.17"}, {"lessThan": "4.17", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.145", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.97", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.40", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.5", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.2-rc1", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\n9p: skip nlink update in cacheless mode to fix WARN_ON\n\nv9fs_dec_count() unconditionally calls drop_nlink() on regular files,\neven when the inode's nlink is already zero. In cacheless mode the\nclient refetches inode metadata from the server (the source of truth)\non every operation, so by the time v9fs_remove() returns, the locally\ncached nlink may already reflect the post-unlink value:\n\n 1. Client initiates unlink, server processes it and sets nlink to 0\n 2. Client refetches inode metadata (nlink=0) before unlink returns\n 3. Client's v9fs_remove() completes successfully\n 4. Client calls v9fs_dec_count() which calls drop_nlink() on nlink=0\n\nThis race is easily triggered under heavy unlink workloads, such as\nstress-ng's unlink stressor, producing the following warning:\n\n WARNING: fs/inode.c:417 at drop_nlink+0x4c/0xc8\n Call trace:\n drop_nlink+0x4c/0xc8\n v9fs_remove+0x1e0/0x250 [9p]\n v9fs_vfs_unlink+0x20/0x38 [9p]\n vfs_unlink+0x13c/0x258\n ...\n\nIn cacheless mode the server is authoritative and the inode is on its\nway out, so locally adjusting nlink buys nothing. Skip v9fs_dec_count()\nentirely when neither CACHE_META nor CACHE_LOOSE is set, which both\navoids the warning and removes a class of nlink races (two concurrent\nunlinkers observing nlink > 0 and both calling drop_nlink()) that an\nnlink == 0 guard alone would only narrow rather than close."}], "id": "CVE-2026-72170", "lastModified": "2026-08-15T06:21:35.100", "metrics": {}, "published": "2026-08-15T06:21:35.100", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/574aa0b4799470ac814479f1138d19efe6262255"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/8d610017c992de705b304d3d727a6e3a86af6149"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/8faccac11e1369adddf5d80f4a45af93f13b2e1a"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/a5a682b016ef5b5384e28f6d652d47a8f8e73d37"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/de79c3f3643841b8659a71958df7cf2a66bfd409"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[ac89b2ef9b55924bcf922251f043ba73a32d05bb,a5a682b016ef5b5384e28f6d652d47a8f8e73d37)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[ac89b2ef9b55924bcf922251f043ba73a32d05bb,de79c3f3643841b8659a71958df7cf2a66bfd409)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[ac89b2ef9b55924bcf922251f043ba73a32d05bb,8d610017c992de705b304d3d727a6e3a86af6149)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[ac89b2ef9b55924bcf922251f043ba73a32d05bb,8faccac11e1369adddf5d80f4a45af93f13b2e1a)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[ac89b2ef9b55924bcf922251f043ba73a32d05bb,574aa0b4799470ac814479f1138d19efe6262255)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "4.17"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,4.17)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.6.145,7.0.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.97,6.13.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.40,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.1.5,7.2.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.2-rc1,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-08-15T15:30:09.433408+00:00", "updated": "2026-08-15T15:30:09.433462+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}