# CVE-2026-98986: linux: In the Linux kernel, the following vulnerability has been resolved:  namespace: remove the fsnotify marks of a mount...

CVE-2026-98986 is fixed in linux on 1 platform by DEBIAN-CVE-2026-98986 (version 7.2.11-1), released October 24, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-98986
- Priority: Routine
- CVSS: n/a
- EPSS: 0.0017
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Oct 23, 2026

## Description

In the Linux kernel, the following vulnerability has been resolved:  namespace: remove the fsnotify marks of a mount namespace in process context  mnt_ns_release() drops the last passive reference of a mount namespace and removes its fanotify marks via fsnotify_mntns_delete(). That takes the mutex of every group with a mark on the namespace and the spinlock of the connector. Fine from process context. But mnt_ns_tree_remove() hands the reference the namespace was allocated with to call_rcu() and so the marks are removed from the RCU softirq:    BUG: sleeping function called from invalid context at kernel/locking/mutex.c:623   in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 0, name: swapper/3    __mutex_lock+0x113/0x24b0    fsnotify_destroy_marks+0x11b/0x3d0    mnt_ns_release_rcu+0x57/0xa0    rcu_core+0x6b6/0x1e40  and lockdep complains about the connector lock being taken from softirq context. A fanotify group with a FAN_MARK_MNTNS mark on the mount namespace of another task is all that's needed. Root in a user namespace can do that for a mount namespace it owns. The task exits and the namespace is freed with the mark still on it.  Remove the marks in free_mnt_ns() before the namespace is handed to RCU. That runs in process context once the last active reference is gone. A mark is added through a file descriptor to the namespace which holds an active reference so no mark can show up after that.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 14 | 7.2.11-1 | [DEBIAN-CVE-2026-98986](https://patchblox.com/security/data/fix/linux/debian-cve-2026-98986.md) | Oct 24, 2026 |

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Data as of 2026-11-08T19:12:23Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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