FKIE_CVE-2026-52990
Vulnerability from fkie_nvd - Published: 2026-06-24 17:17 - Updated: 2026-07-14 16:42
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
fsnotify: fix inode reference leak in fsnotify_recalc_mask()
fsnotify_recalc_mask() fails to handle the return value of
__fsnotify_recalc_mask(), which may return an inode pointer that needs
to be released via fsnotify_drop_object() when the connector's HAS_IREF
flag transitions from set to cleared.
This manifests as a hung task with the following call trace:
INFO: task umount:1234 blocked for more than 120 seconds.
Call Trace:
__schedule
schedule
fsnotify_sb_delete
generic_shutdown_super
kill_anon_super
cleanup_mnt
task_work_run
do_exit
do_group_exit
The race window that triggers the iref leak:
Thread A (adding mark) Thread B (removing mark)
────────────────────── ────────────────────────
fsnotify_add_mark_locked():
fsnotify_add_mark_list():
spin_lock(conn->lock)
add mark_B(evictable) to list
spin_unlock(conn->lock)
return
/* ---- gap: no lock held ---- */
fsnotify_detach_mark(mark_A):
spin_lock(mark_A->lock)
clear ATTACHED flag on mark_A
spin_unlock(mark_A->lock)
fsnotify_put_mark(mark_A)
fsnotify_recalc_mask():
spin_lock(conn->lock)
__fsnotify_recalc_mask():
/* mark_A skipped: ATTACHED cleared */
/* only mark_B(evictable) remains */
want_iref = false
has_iref = true /* not yet cleared */
-> HAS_IREF transitions true -> false
-> returns inode pointer
spin_unlock(conn->lock)
/* BUG: return value discarded!
* iput() and fsnotify_put_sb_watched_objects()
* are never called */
Fix this by deferring the transition true -> false of HAS_IREF flag from
fsnotify_recalc_mask() (Thread A) to fsnotify_put_mark() (thread B).
References
Impacted products
| Vendor | Product | Version | |
|---|---|---|---|
| linux | linux_kernel | * | |
| linux | linux_kernel | * | |
| linux | linux_kernel | * | |
| linux | linux_kernel | * | |
| linux | linux_kernel | * | |
| linux | linux_kernel | 7.1 |
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"fs/notify/mark.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "8c8afa6444e6bdc145d2bf2f3aeeca6da3e36b42",
"status": "affected",
"version": "c3638b5b13740fa31762d414bbce8b7a694e582a",
"versionType": "git"
},
{
"lessThan": "b740cc86816bbc87902ae9db74cd21abde3c8d63",
"status": "affected",
"version": "c3638b5b13740fa31762d414bbce8b7a694e582a",
"versionType": "git"
},
{
"lessThan": "5c80289503da3658e3df80280598c68d181eadbd",
"status": "affected",
"version": "c3638b5b13740fa31762d414bbce8b7a694e582a",
"versionType": "git"
},
{
"lessThan": "4aca914ac152f5d055ddcb36704d1e539ac08977",
"status": "affected",
"version": "c3638b5b13740fa31762d414bbce8b7a694e582a",
"versionType": "git"
},
{
"status": "affected",
"version": "ff34ebaa6f6dc1eebce6a8d6f12a1566f33d00fe",
"versionType": "git"
},
{
"status": "affected",
"version": "4f145b67c075324b13d6ae7d5abb6e7a1dbac26d",
"versionType": "git"
},
{
"lessThan": "5.11",
"status": "affected",
"version": "5.10.220",
"versionType": "semver"
},
{
"lessThan": "5.16",
"status": "affected",
"version": "5.15.154",
"versionType": "semver"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"fs/notify/mark.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "5.19"
},
{
"lessThan": "5.19",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.91",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.33",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.0.*",
"status": "unaffected",
"version": "7.0.10",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.1",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"configurations": [
{
"nodes": [
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"matchCriteriaId": "F5F69C49-7A3F-4F7F-92F8-9E479FA2CCD3",
"versionEndExcluding": "5.11",
"versionStartIncluding": "5.10.220",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "21EE109E-592F-4A01-B5D2-F078967481BA",
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},
{
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},
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{
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"vulnerable": true
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"negate": false,
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],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "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 inode pointer that needs\nto be released via fsnotify_drop_object() when the connector\u0027s 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 \u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500 \u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\n fsnotify_add_mark_locked():\n fsnotify_add_mark_list():\n spin_lock(conn-\u003elock)\n add mark_B(evictable) to list\n spin_unlock(conn-\u003elock)\n return\n\n /* ---- gap: no lock held ---- */\n\n fsnotify_detach_mark(mark_A):\n spin_lock(mark_A-\u003elock)\n clear ATTACHED flag on mark_A\n spin_unlock(mark_A-\u003elock)\n fsnotify_put_mark(mark_A)\n\n fsnotify_recalc_mask():\n spin_lock(conn-\u003elock)\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 -\u003e HAS_IREF transitions true -\u003e false\n -\u003e returns inode pointer\n spin_unlock(conn-\u003elock)\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 -\u003e false of HAS_IREF flag from\nfsnotify_recalc_mask() (Thread A) to fsnotify_put_mark() (thread B)."
}
],
"id": "CVE-2026-52990",
"lastModified": "2026-07-14T16:42:40.580",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 5.5,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"version": "3.1"
},
"exploitabilityScore": 1.8,
"impactScore": 3.6,
"source": "nvd@nist.gov",
"type": "Primary"
}
]
},
"published": "2026-06-24T17:17:09.833",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/4aca914ac152f5d055ddcb36704d1e539ac08977"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/5c80289503da3658e3df80280598c68d181eadbd"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
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"url": "https://git.kernel.org/stable/c/8c8afa6444e6bdc145d2bf2f3aeeca6da3e36b42"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
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"url": "https://git.kernel.org/stable/c/b740cc86816bbc87902ae9db74cd21abde3c8d63"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Analyzed",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "NVD-CWE-Other"
}
],
"source": "nvd@nist.gov",
"type": "Primary"
}
]
}
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Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
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- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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