{"api_version":"1","generated_at":"2026-11-05T23:41:19+00:00","cve":"CVE-2026-99175","urls":{"html":"https://cve.report/CVE-2026-99175","api":"https://cve.report/api/cve/CVE-2026-99175.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-99175","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-99175"},"summary":{"title":"fsnotify: prevent mark additions during connector teardown","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nfsnotify: prevent mark additions during connector teardown\n\nfsnotify_destroy_marks() keeps a reference to its current mark while it\ndrops conn->lock to destroy the mark. This stabilizes the forward-walk\ncursor, but does not prevent a new mark from being inserted before it.\nFor example, an inotify watch re-added after IN_IGNORED sorts before the\nold, detached mark for the same group. The walk can miss the replacement\nand then detach the entire connector from the object.\n\nThe replacement is still on its group's marks_list and, for inotify, in\nthe watch IDR. The group mutex no longer protects the connector's object\nfrom disappearing. An unprivileged fdinfo read racing the final detach\ncan consequently call igrab(NULL):\n\n  BUG: KASAN: null-ptr-deref in igrab+0x24/0x100\n  Write of size 4 at addr 0000000000000148\n  Call Trace:\n   igrab+0x24/0x100\n   inotify_show_fdinfo+0x1dc/0x5e0\n   seq_show+0x397/0x690\n\nSet a DESTROYING flag under conn->lock before starting the walk, and\nreject new marks on that connector with -ENOENT. The existing add-mark\nerror paths undo the temporary group-list entry and the backend's watch\nallocation. Do not wait for teardown while holding the group mutex,\nwhich the destroyer needs. Once the old connector is detached, an add\ncan install a fresh connector as before.\n\nThis closes the insertion race for all object types using the common\nconnector teardown, without changing the mark reference or SRCU lifetime\nrules.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-10-28 11:17:38","updated_at":"2026-10-30 13:21:51"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/952501bfc6e5e654ac4a17ec9d90c1ec614bd9f1","name":"https://git.kernel.org/stable/c/952501bfc6e5e654ac4a17ec9d90c1ec614bd9f1","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/587d80966dcce2824f13fd32dab83bf882acf66f","name":"https://git.kernel.org/stable/c/587d80966dcce2824f13fd32dab83bf882acf66f","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/f7def717c06aea7004905e4d1568c3691ef9825d","name":"https://git.kernel.org/stable/c/f7def717c06aea7004905e4d1568c3691ef9825d","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/61133f15773b907bada651a02d9c6d38eae37c48","name":"https://git.kernel.org/stable/c/61133f15773b907bada651a02d9c6d38eae37c48","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/36ebddca56b9d8993d6dc984fdecc748ee1f5e06","name":"https://git.kernel.org/stable/c/36ebddca56b9d8993d6dc984fdecc748ee1f5e06","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/da2f9aa89ef1b1fe7a7c6e1a8ddacd9c975e86aa","name":"https://git.kernel.org/stable/c/da2f9aa89ef1b1fe7a7c6e1a8ddacd9c975e86aa","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/d28a460a2237220d9ccbdd3baac6eaead44e96cb","name":"https://git.kernel.org/stable/c/d28a460a2237220d9ccbdd3baac6eaead44e96cb","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/472589eacdf10b5f9bd10b333957ed5291b2544b","name":"https://git.kernel.org/stable/c/472589eacdf10b5f9bd10b333957ed5291b2544b","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-99175","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-99175","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6b3f05d24d355f50f3d9814304650fcab0efb482 f7def717c06aea7004905e4d1568c3691ef9825d git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6b3f05d24d355f50f3d9814304650fcab0efb482 da2f9aa89ef1b1fe7a7c6e1a8ddacd9c975e86aa git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6b3f05d24d355f50f3d9814304650fcab0efb482 587d80966dcce2824f13fd32dab83bf882acf66f git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6b3f05d24d355f50f3d9814304650fcab0efb482 d28a460a2237220d9ccbdd3baac6eaead44e96cb git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 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semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.15.224 5.15.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.191 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.161 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.115 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.59 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.13 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"99175","cve":"CVE-2026-99175","epss":"0.001770000","percentile":"0.072830000","score_date":"2026-11-01","updated_at":"2026-11-02 00:05:55"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["fs/notify/mark.c","include/linux/fsnotify_backend.h"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"f7def717c06aea7004905e4d1568c3691ef9825d","status":"affected","version":"6b3f05d24d355f50f3d9814304650fcab0efb482","versionType":"git"},{"lessThan":"da2f9aa89ef1b1fe7a7c6e1a8ddacd9c975e86aa","status":"affected","version":"6b3f05d24d355f50f3d9814304650fcab0efb482","versionType":"git"},{"lessThan":"587d80966dcce2824f13fd32dab83bf882acf66f","status":"affected","version":"6b3f05d24d355f50f3d9814304650fcab0efb482","versionType":"git"},{"lessThan":"d28a460a2237220d9ccbdd3baac6eaead44e96cb","status":"affected","version":"6b3f05d24d355f50f3d9814304650fcab0efb482","versionType":"git"},{"lessThan":"61133f15773b907bada651a02d9c6d38eae37c48","status":"affected","version":"6b3f05d24d355f50f3d9814304650fcab0efb482","versionType":"git"},{"lessThan":"952501bfc6e5e654ac4a17ec9d90c1ec614bd9f1","status":"affected","version":"6b3f05d24d355f50f3d9814304650fcab0efb482","versionType":"git"},{"lessThan":"472589eacdf10b5f9bd10b333957ed5291b2544b","status":"affected","version":"6b3f05d24d355f50f3d9814304650fcab0efb482","versionType":"git"},{"lessThan":"36ebddca56b9d8993d6dc984fdecc748ee1f5e06","status":"affected","version":"6b3f05d24d355f50f3d9814304650fcab0efb482","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["fs/notify/mark.c","include/linux/fsnotify_backend.h"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"4.12"},{"lessThan":"4.12","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"5.10.*","status":"unaffected","version":"5.10.273","versionType":"semver"},{"lessThanOrEqual":"5.15.*","status":"unaffected","version":"5.15.224","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.191","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.161","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.115","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.59","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.13","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.10.273","versionStartIncluding":"4.12","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.15.224","versionStartIncluding":"4.12","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.191","versionStartIncluding":"4.12","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.161","versionStartIncluding":"4.12","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.115","versionStartIncluding":"4.12","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.59","versionStartIncluding":"4.12","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.13","versionStartIncluding":"4.12","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3","versionStartIncluding":"4.12","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nfsnotify: prevent mark additions during connector teardown\n\nfsnotify_destroy_marks() keeps a reference to its current mark while it\ndrops conn->lock to destroy the mark. This stabilizes the forward-walk\ncursor, but does not prevent a new mark from being inserted before it.\nFor example, an inotify watch re-added after IN_IGNORED sorts before the\nold, detached mark for the same group. The walk can miss the replacement\nand then detach the entire connector from the object.\n\nThe replacement is still on its group's marks_list and, for inotify, in\nthe watch IDR. The group mutex no longer protects the connector's object\nfrom disappearing. An unprivileged fdinfo read racing the final detach\ncan consequently call igrab(NULL):\n\n  BUG: KASAN: null-ptr-deref in igrab+0x24/0x100\n  Write of size 4 at addr 0000000000000148\n  Call Trace:\n   igrab+0x24/0x100\n   inotify_show_fdinfo+0x1dc/0x5e0\n   seq_show+0x397/0x690\n\nSet a DESTROYING flag under conn->lock before starting the walk, and\nreject new marks on that connector with -ENOENT. The existing add-mark\nerror paths undo the temporary group-list entry and the backend's watch\nallocation. Do not wait for teardown while holding the group mutex,\nwhich the destroyer needs. Once the old connector is detached, an add\ncan install a fresh connector as before.\n\nThis closes the insertion race for all object types using the common\nconnector teardown, without changing the mark reference or SRCU lifetime\nrules."}],"providerMetadata":{"dateUpdated":"2026-10-30T12:42:39.046Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/f7def717c06aea7004905e4d1568c3691ef9825d"},{"url":"https://git.kernel.org/stable/c/da2f9aa89ef1b1fe7a7c6e1a8ddacd9c975e86aa"},{"url":"https://git.kernel.org/stable/c/587d80966dcce2824f13fd32dab83bf882acf66f"},{"url":"https://git.kernel.org/stable/c/d28a460a2237220d9ccbdd3baac6eaead44e96cb"},{"url":"https://git.kernel.org/stable/c/61133f15773b907bada651a02d9c6d38eae37c48"},{"url":"https://git.kernel.org/stable/c/952501bfc6e5e654ac4a17ec9d90c1ec614bd9f1"},{"url":"https://git.kernel.org/stable/c/472589eacdf10b5f9bd10b333957ed5291b2544b"},{"url":"https://git.kernel.org/stable/c/36ebddca56b9d8993d6dc984fdecc748ee1f5e06"}],"title":"fsnotify: prevent mark additions during connector teardown","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-99175","datePublished":"2026-10-28T10:35:29.760Z","dateReserved":"2026-09-25T10:25:14.399Z","dateUpdated":"2026-10-30T12:42:39.046Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-10-28 11:17:38","lastModifiedDate":"2026-10-30 13:21:51","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"99175","Ordinal":"1","Title":"fsnotify: prevent mark additions during connector teardown","CVE":"CVE-2026-99175","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"99175","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nfsnotify: prevent mark additions during connector teardown\n\nfsnotify_destroy_marks() keeps a reference to its current mark while it\ndrops conn->lock to destroy the mark. This stabilizes the forward-walk\ncursor, but does not prevent a new mark from being inserted before it.\nFor example, an inotify watch re-added after IN_IGNORED sorts before the\nold, detached mark for the same group. The walk can miss the replacement\nand then detach the entire connector from the object.\n\nThe replacement is still on its group's marks_list and, for inotify, in\nthe watch IDR. The group mutex no longer protects the connector's object\nfrom disappearing. An unprivileged fdinfo read racing the final detach\ncan consequently call igrab(NULL):\n\n  BUG: KASAN: null-ptr-deref in igrab+0x24/0x100\n  Write of size 4 at addr 0000000000000148\n  Call Trace:\n   igrab+0x24/0x100\n   inotify_show_fdinfo+0x1dc/0x5e0\n   seq_show+0x397/0x690\n\nSet a DESTROYING flag under conn->lock before starting the walk, and\nreject new marks on that connector with -ENOENT. The existing add-mark\nerror paths undo the temporary group-list entry and the backend's watch\nallocation. Do not wait for teardown while holding the group mutex,\nwhich the destroyer needs. Once the old connector is detached, an add\ncan install a fresh connector as before.\n\nThis closes the insertion race for all object types using the common\nconnector teardown, without changing the mark reference or SRCU lifetime\nrules.","Type":"Description","Title":"fsnotify: prevent mark additions during connector teardown"}]}}}