cve-2026-46040
MEDIUM CVSS 5.5 nvd
Description
In the Linux kernel, the following vulnerability has been resolved: inotify: fix watch count leak when fsnotify_add_inode_mark_locked() fails When fsnotify_add_inode_mark_locked() fails in inotify_new_watch(), the error path calls inotify_remove_from_idr() but does not call dec_inotify_watches() to undo the preceding inc_inotify_watches(). This leaks a watch count, and repeated failures can exhaust the max_user_watches limit with -ENOSPC even when no watches are active. Prior to commit 1cce1eea0aff ("inotify: Convert to using per-namespace limits"), the watch count was incremented after fsnotify_add_mark_locked() succeeded, so this path was not affected. The conversion moved inc_inotify_watches() before the mark insertion without adding the corresponding rollback. Add the missing dec_inotify_watches() call in the error path.
Timeline
- Published
- 2026-05-27
- Last Modified
- 2026-09-08
CVSS Details
- Attack Vector
- LOCAL
- Attack Complexity
- LOW
- Privileges Required
- LOW
Affected Products
- linux linux_kernel
CVSS metrics
| Version | Base | Severity | Vector | Exploitability | Impact | Source |
|---|---|---|---|---|---|---|
| 3.1 | 5.5 | MEDIUM | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
1.8 | 3.6 | nvd@nist.gov |
CPE configurations
OR
| CPE | Version range | Vulnerable |
|---|---|---|
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
>= 4.11, < 5.10.258 | yes |
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
>= 5.11, < 5.15.209 | yes |
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
>= 5.16, < 6.1.175 | yes |
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
>= 6.2, < 6.6.140 | yes |
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
>= 6.7, < 6.12.86 | yes |
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
>= 6.13, < 6.18.27 | yes |
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
>= 6.19, < 7.0.4 | yes |
NVD metadata
- NVD status
- Modified
- Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/10edf7e0ffdc7faa18e2244b17722c1b882b8273 Patch
- https://git.kernel.org/stable/c/3ab58cf42c46bf2366d2f55ae5c59299d5e178b7 Patch
- https://git.kernel.org/stable/c/3ad9ccea1b25435f6179b57aa891960beb7ce8f9 Patch
- https://git.kernel.org/stable/c/6a320935fa4293e9e599ec9f85dc9eb3be7029f8 Patch
- https://git.kernel.org/stable/c/73ddc8518a32baff6bc17afda4ee1ebae5b4ed12 Patch
- https://git.kernel.org/stable/c/8bcc1cd237ab5ccfdd102869fa031c541943cf40 Patch
- https://git.kernel.org/stable/c/9e48844f708eb48bae4e79cb21edc097c966306d Patch
- https://git.kernel.org/stable/c/fdaa42ca370d056428e5e171247c8fdce8dff36a Patch
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html
Linked Vulnerabilities
{
"cvss": 5.5,
"datePublished": "2026-05-27T14:17:23.387",
"dateUpdated": "2026-09-08T09:18:07.063",
"description": "In the Linux kernel, the following vulnerability has been resolved:\n\ninotify: fix watch count leak when fsnotify_add_inode_mark_locked() fails\n\nWhen fsnotify_add_inode_mark_locked() fails in inotify_new_watch(),\nthe error path calls inotify_remove_from_idr() but does not call\ndec_inotify_watches() to undo the preceding inc_inotify_watches().\nThis leaks a watch count, and repeated failures can exhaust the\nmax_user_watches limit with -ENOSPC even when no watches are active.\n\nPrior to commit 1cce1eea0aff (\"inotify: Convert to using per-namespace\nlimits\"), the watch count was incremented after fsnotify_add_mark_locked()\nsucceeded, so this path was not affected. The conversion moved\ninc_inotify_watches() before the mark insertion without adding the\ncorresponding rollback.\n\nAdd the missing dec_inotify_watches() call in the error path.",
"id": "CVE-2026-46040",
"raw": {
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"fs/notify/inotify/inotify_user.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "3ab58cf42c46bf2366d2f55ae5c59299d5e178b7",
"status": "affected",
"version": "1cce1eea0aff51201753fcaca421df825b0813b6",
"versionType": "git"
},
{
"lessThan": "10edf7e0ffdc7faa18e2244b17722c1b882b8273",
"status": "affected",
"version": "1cce1eea0aff51201753fcaca421df825b0813b6",
"versionType": "git"
},
{
"lessThan": "3ad9ccea1b25435f6179b57aa891960beb7ce8f9",
"status": "affected",
"version": "1cce1eea0aff51201753fcaca421df825b0813b6",
"versionType": "git"
},
{
"lessThan": "8bcc1cd237ab5ccfdd102869fa031c541943cf40",
"status": "affected",
"version": "1cce1eea0aff51201753fcaca421df825b0813b6",
"versionType": "git"
},
{
"lessThan": "73ddc8518a32baff6bc17afda4ee1ebae5b4ed12",
"status": "affected",
"version": "1cce1eea0aff51201753fcaca421df825b0813b6",
"versionType": "git"
},
{
"lessThan": "fdaa42ca370d056428e5e171247c8fdce8dff36a",
"status": "affected",
"version": "1cce1eea0aff51201753fcaca421df825b0813b6",
"versionType": "git"
},
{
"lessThan": "9e48844f708eb48bae4e79cb21edc097c966306d",
"status": "affected",
"version": "1cce1eea0aff51201753fcaca421df825b0813b6",
"versionType": "git"
},
{
"lessThan": "6a320935fa4293e9e599ec9f85dc9eb3be7029f8",
"status": "affected",
"version": "1cce1eea0aff51201753fcaca421df825b0813b6",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"fs/notify/inotify/inotify_user.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "4.11"
},
{
"lessThan": "4.11",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.258",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.209",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.175",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.140",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.86",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.27",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.0.*",
"status": "unaffected",
"version": "7.0.4",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.1",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"affectedData": [
{
"defaultStatus": "unknown",
"product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP",
"vendor": "Siemens",
"versions": [
{
"lessThan": "*",
"status": "affected",
"version": "V3.1.6",
"versionType": "custom"
}
]
},
{
"defaultStatus": "unknown",
"product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP",
"vendor": "Siemens",
"versions": [
{
"lessThan": "*",
"status": "affected",
"version": "V3.1.6",
"versionType": "custom"
}
]
},
{
"defaultStatus": "unknown",
"product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP",
"vendor": "Siemens",
"versions": [
{
"lessThan": "*",
"status": "affected",
"version": "V3.1.6",
"versionType": "custom"
}
]
},
{
"defaultStatus": "unknown",
"product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP",
"vendor": "Siemens",
"versions": [
{
"lessThan": "*",
"status": "affected",
"version": "V3.1.6",
"versionType": "custom"
}
]
},
{
"defaultStatus": "unknown",
"product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP",
"vendor": "Siemens",
"versions": [
{
"lessThan": "*",
"status": "affected",
"version": "V3.1.6",
"versionType": "custom"
}
]
}
],
"source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"
}
],
"configurations": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "EDD978C9-3435-4AC5-AE97-062846CF653F",
"versionEndExcluding": "5.10.258",
"versionStartIncluding": "4.11",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "919C10A9-7951-4A74-BADD-C135A0A8D8B4",
"versionEndExcluding": "5.15.209",
"versionStartIncluding": "5.11",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "92385813-D91D-480D-83A1-F423D2CBB2BA",
"versionEndExcluding": "6.1.175",
"versionStartIncluding": "5.16",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "A1A92866-F406-43B5-B2D1-CFC274753E9D",
"versionEndExcluding": "6.6.140",
"versionStartIncluding": "6.2",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "55DA1C62-9991-451E-B8A8-E0004E00F789",
"versionEndExcluding": "6.12.86",
"versionStartIncluding": "6.7",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "A10AC84F-C058-47D5-85B4-E6E51A613B74",
"versionEndExcluding": "6.18.27",
"versionStartIncluding": "6.13",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "CDB78D6D-22C3-4154-B0D0-94AF1CE5C2E3",
"versionEndExcluding": "7.0.4",
"versionStartIncluding": "6.19",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\ninotify: fix watch count leak when fsnotify_add_inode_mark_locked() fails\n\nWhen fsnotify_add_inode_mark_locked() fails in inotify_new_watch(),\nthe error path calls inotify_remove_from_idr() but does not call\ndec_inotify_watches() to undo the preceding inc_inotify_watches().\nThis leaks a watch count, and repeated failures can exhaust the\nmax_user_watches limit with -ENOSPC even when no watches are active.\n\nPrior to commit 1cce1eea0aff (\"inotify: Convert to using per-namespace\nlimits\"), the watch count was incremented after fsnotify_add_mark_locked()\nsucceeded, so this path was not affected. The conversion moved\ninc_inotify_watches() before the mark insertion without adding the\ncorresponding rollback.\n\nAdd the missing dec_inotify_watches() call in the error path."
}
],
"id": "CVE-2026-46040",
"lastModified": "2026-09-08T09:18:07.063",
"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": "2026-05-27T14:17:23.387",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/10edf7e0ffdc7faa18e2244b17722c1b882b8273"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/3ab58cf42c46bf2366d2f55ae5c59299d5e178b7"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/3ad9ccea1b25435f6179b57aa891960beb7ce8f9"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/6a320935fa4293e9e599ec9f85dc9eb3be7029f8"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/73ddc8518a32baff6bc17afda4ee1ebae5b4ed12"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/8bcc1cd237ab5ccfdd102869fa031c541943cf40"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/9e48844f708eb48bae4e79cb21edc097c966306d"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/fdaa42ca370d056428e5e171247c8fdce8dff36a"
},
{
"source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e",
"url": "https://cert-portal.siemens.com/productcert/html/ssa-019113.html"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Modified",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "NVD-CWE-Other"
}
],
"source": "nvd@nist.gov",
"type": "Primary"
}
]
},
"severity": "MEDIUM",
"source": "nvd",
"title": "In the Linux kernel, the following vulnerability has been resolved:\n\ninotify: fix watch count leak when fsnotify_add_..."
}