Improper Update of Reference Count Affecting kernel-rt-debug-modules package, versions *


Severity

Recommended
medium

Based on Red Hat Enterprise Linux security rating.

Threat Intelligence

EPSS
0.6% (47th percentile)

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  • Snyk IDSNYK-RHEL10-KERNELRTDEBUGMODULES-20240270
  • published29 Sept 2026
  • disclosed25 Sept 2026

Introduced: 25 Sep 2026

NewCVE-2026-97557  (opens in a new tab)
CWE-911  (opens in a new tab)

How to fix?

There is no fixed version for RHEL:10 kernel-rt-debug-modules.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-rt-debug-modules package and not the kernel-rt-debug-modules package as distributed by RHEL. See How to fix? for RHEL:10 relevant fixed versions and status.

In the Linux kernel, the following vulnerability has been resolved:

smb: client: avoid leaking refcount in cifs_queue_oplock_break()

cifs_queue_oplock_break() unconditionally takes a reference on the target file before queueing cifs_oplock_break(). Only that work item decreases the reference counter again.

If another oplock break arrives while that work is still queued, queue_work() will return false and not queue this second work item. As a result, we will never reach the point to drop the file reference again and are leaking this reference. This can be triggered when interacting with a slow-responding server.

As a result, later unmount operations for this file system will fail with

BUG: Dentry ... still in use (1) [unmount of cifs cifs] VFS: Busy inodes after unmount of cifs (cifs) kernel BUG at fs/super.c:777!

Fix this by only incrementing the reference count if the work has been queued successfully. Taking it after queue_work() is safe because all three callers hold tcon->open_file_lock across the call and _cifsFileInfo_put() decrements under that same lock, so a worker that starts the handler in the window cannot drop the reference before it has been taken.

CVSS Base Scores

version 3.1