CVE-2026-46040
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.
Executive briefing
The source record describes: 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. The practical risk depends on whether an affected product/version is present, reachable and configured in an exploitable way. Review the affected-product evidence and linked vendor advisories before assigning exposure status.
Evidence confidence: Moderate Evidence-derived, not an exploitability verdict
Severity & attack characteristics
CVSS vector:CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Technical explanation & impact
The technical mechanism is not expanded beyond the source description unless a referenced advisory supplies additional evidence. Read the linked vendor/CERT advisories for root-cause detail.
Potential impact must be interpreted from the published CVSS impact metrics and the affected component. A CVSS impact score is not proof that a particular asset is exploitable.
Weakness classification
NVD-CWE-OtherAffected products and versions
Products below are parsed from NVD vulnerable CPE configuration entries. Version boundaries are shown as published; verify applicability with the vendor.
| Vendor | Product | Version evidence |
|---|---|---|
| linux | linux_kernel | from (inclusive) 6.19; before 7.0.4 |
Remediation & validation
- Identify exposure by comparing the affected product and version ranges with your asset inventory, SBOM and externally exposed services.
- Review the linked vendor security advisory or patch notes. Upgrade to a vendor-confirmed fixed release; do not infer a fixed version from the CVE description.
- Until patched, consider restricting network access or disabling the affected feature where operationally safe. These are temporary controls, not a substitute for a vendor fix.
- Validate the remediation with a version check and vulnerability rescan, then retain change evidence.
No fixed version is displayed unless it is explicitly established by a vendor advisory. Follow the vendor's release notes for exact product and branch applicability.
Vendor advisories, patches & exploit references
- https://git.kernel.org/stable/c/10edf7e0ffdc7faa18e2244b17722c1b882b8273 PATCH 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- https://git.kernel.org/stable/c/3ab58cf42c46bf2366d2f55ae5c59299d5e178b7 PATCH 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- https://git.kernel.org/stable/c/3ad9ccea1b25435f6179b57aa891960beb7ce8f9 PATCH 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- https://git.kernel.org/stable/c/6a320935fa4293e9e599ec9f85dc9eb3be7029f8 PATCH 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- https://git.kernel.org/stable/c/73ddc8518a32baff6bc17afda4ee1ebae5b4ed12 PATCH 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- https://git.kernel.org/stable/c/8bcc1cd237ab5ccfdd102869fa031c541943cf40 PATCH 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- https://git.kernel.org/stable/c/9e48844f708eb48bae4e79cb21edc097c966306d PATCH 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- https://git.kernel.org/stable/c/fdaa42ca370d056428e5e171247c8fdce8dff36a PATCH 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html REFERENCE 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
- https://cert-portal.siemens.com/productcert/html/ssa-457936.html REFERENCE 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
- https://cert-portal.siemens.com/productcert/html/ssa-784472.html REFERENCE 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e