{"cve":"CVE-2026-99175","nvd":{"published":"2026-10-28T11:17:38.150","modified":"2026-10-28T11:17:38.150","status":"Received","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.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/36ebddca56b9d8993d6dc984fdecc748ee1f5e06","https://git.kernel.org/stable/c/472589eacdf10b5f9bd10b333957ed5291b2544b","https://git.kernel.org/stable/c/952501bfc6e5e654ac4a17ec9d90c1ec614bd9f1"],"products":[],"source":"nvd","synced_at":"2026-10-28T11:37:51.394563875+00:00"},"epss":null,"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}