inotify: fix watch count leak when fsnotify_add_inode_mark_locked() fails
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 4 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 4.11 and later | 5.10.258, 5.15.209, 6.1.175, 6.6.140, 6.12.86, 6.18.27, 7.0.4, 7.1 | Patch available | CNA |
- Linux VendorLinux Affected 4.11 and later Fixed in 5.10.258, 5.15.209, 6.1.175, 6.6.140, 6.12.86, 6.18.27, 7.0.4, 7.1 Patch available CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 4.11 to before 5.10.258; 5.11 to before 5.15.209; 5.16 to before 6.1.175; 6.2 to before 6.6.140; 6.7 to before 6.12.86; 6.13 to before 6.18.27; 6.19 to before 7.0.4 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 4.11 to before 5.10.258; 5.11 to before 5.15.209; 5.16 to before 6.1.175; 6.2 to before 6.6.140; 6.7 to before 6.12.86; 6.13 to before 6.18.27; 6.19 to before 7.0.4 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.10.258, 5.15.209, 6.1.175, 6.6.140, 6.12.86, 6.18.27, 7.0.4, 7.1
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
Not affected: 1 product
- Red Hat Enterprise Linux 7
Timeline
- 2026-10-02 Threatist record created from CVE-2026-46040
- 2026-10-03 Alias added: GHSA-38g3-xqxq-2v2p
- 2026-11-06 CISA SSVC decision points changed
References
Patch 8
- https://git.kernel.org/stable/c/3ab58cf42c46bf2366d2f55ae5c59299d5e178b7
- https://git.kernel.org/stable/c/10edf7e0ffdc7faa18e2244b17722c1b882b8273
- https://git.kernel.org/stable/c/3ad9ccea1b25435f6179b57aa891960beb7ce8f9
- https://git.kernel.org/stable/c/8bcc1cd237ab5ccfdd102869fa031c541943cf40
- https://git.kernel.org/stable/c/73ddc8518a32baff6bc17afda4ee1ebae5b4ed12
- https://git.kernel.org/stable/c/fdaa42ca370d056428e5e171247c8fdce8dff36a
- https://git.kernel.org/stable/c/9e48844f708eb48bae4e79cb21edc097c966306d
- https://git.kernel.org/stable/c/6a320935fa4293e9e599ec9f85dc9eb3be7029f8
More Linux Kernel vulnerabilities
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- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2026-46040 · CVE Program
- CVE-2026-46040 · NVD
- FIRST EPSS
- GHSA-38g3-xqxq-2v2p · GitHub Advisory Database · CC BY 4.0
- CVE-2026-46040 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences