{"id":"CVE-2026-52990","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nfsnotify: fix inode reference leak in fsnotify_recalc_mask()\n\nfsnotify_recalc_mask() fails to handle the return value of\n__fsnotify_recalc_mask(), which may return an i…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nfsnotify: fix inode reference leak in fsnotify_recalc_mask()\n\nfsnotify_recalc_mask() fails to handle the return value of\n__fsnotify_recalc_mask(), which may return an i…","severity":"none","published":"2026-06-24","updated":"2026-07-10","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-52990","references":[{"url":"https://git.kernel.org/stable/c/4aca914ac152f5d055ddcb36704d1e539ac08977","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/5c80289503da3658e3df80280598c68d181eadbd","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/8c8afa6444e6bdc145d2bf2f3aeeca6da3e36b42","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/b740cc86816bbc87902ae9db74cd21abde3c8d63","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/926ec3937b28d30c08427053c8d8af7f9e086d82"}],"tags":["nvd","cve.org"],"epss":0.00128,"epssPercentile":0.02419,"ingestedAt":"2026-07-11T13:13:25.601Z","vendor":"Linux","product":"Linux","affected":["Linux >= c3638b5b13740fa31762d414bbce8b7a694e582a < 926ec3937b28d30c08427053c8d8af7f9e086d82","Linux >= c3638b5b13740fa31762d414bbce8b7a694e582a < 8c8afa6444e6bdc145d2bf2f3aeeca6da3e36b42","Linux >= c3638b5b13740fa31762d414bbce8b7a694e582a < b740cc86816bbc87902ae9db74cd21abde3c8d63","Linux >= c3638b5b13740fa31762d414bbce8b7a694e582a < 5c80289503da3658e3df80280598c68d181eadbd","Linux >= c3638b5b13740fa31762d414bbce8b7a694e582a < 4aca914ac152f5d055ddcb36704d1e539ac08977","Linux ff34ebaa6f6dc1eebce6a8d6f12a1566f33d00fe","Linux 4f145b67c075324b13d6ae7d5abb6e7a1dbac26d","Linux >= 5.10.220 < 5.11","Linux >= 5.15.154 < 5.16","Linux 5.19"],"slug":"CVE-2026-52990","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nfsnotify: fix inode reference leak in fsnotify_recalc_mask()\n\nfsnotify_recalc_mask() fails to handle the return value of\n__fsnotify_recalc_mask(), which may return an inode pointer that needs\nto be released via fsnotify_drop_object() when the connector's HAS_IREF\nflag transitions from set to cleared.\n\nThis manifests as a hung task with the following call trace:\n\n  INFO: task umount:1234 blocked for more than 120 seconds.\n  Call Trace:\n   __schedule\n   schedule\n   fsnotify_sb_delete\n   generic_shutdown_super\n   kill_anon_super\n   cleanup_mnt\n   task_work_run\n   do_exit\n   do_group_exit\n\nThe race window that triggers the iref leak:\n\n  Thread A (adding mark)              Thread B (removing mark)\n  ──────────────────────              ────────────────────────\n  fsnotify_add_mark_locked():\n    fsnotify_add_mark_list():\n      spin_lock(conn->lock)\n      add mark_B(evictable) to list\n      spin_unlock(conn->lock)\n    return\n\n    /* ---- gap: no lock held ---- */\n\n                                      fsnotify_detach_mark(mark_A):\n                                        spin_lock(mark_A->lock)\n                                        clear ATTACHED flag on mark_A\n                                        spin_unlock(mark_A->lock)\n                                        fsnotify_put_mark(mark_A)\n\n    fsnotify_recalc_mask():\n      spin_lock(conn->lock)\n      __fsnotify_recalc_mask():\n        /* mark_A skipped: ATTACHED cleared */\n        /* only mark_B(evictable) remains */\n        want_iref = false\n        has_iref = true  /* not yet cleared */\n        -> HAS_IREF transitions true -> false\n        -> returns inode pointer\n      spin_unlock(conn->lock)\n      /* BUG: return value discarded!\n       * iput() and fsnotify_put_sb_watched_objects()\n       * are never called */\n\nFix this by deferring the transition true -> false of HAS_IREF flag from\nfsnotify_recalc_mask() (Thread A) to fsnotify_put_mark() (thread B).\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}