NULL Pointer Dereference Affecting kernel-default-base package, versions <6.4.0-150700.53.81.1.150700.17.45.1


Severity

Recommended
0.0
medium
0
10

Based on SUSE Linux Enterprise Server security rating.

Threat Intelligence

EPSS
0.12% (2nd percentile)

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  • Snyk IDSNYK-SLES157-KERNELDEFAULTBASE-19904905
  • published18 Sept 2026
  • disclosed17 Sept 2026

Introduced: 17 Sep 2026

NewCVE-2026-43271  (opens in a new tab)
CWE-476  (opens in a new tab)

How to fix?

Upgrade SLES:15.7 kernel-default-base to version 6.4.0-150700.53.81.1.150700.17.45.1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-default-base package and not the kernel-default-base package as distributed by SLES. See How to fix? for SLES:15.7 relevant fixed versions and status.

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

md-cluster: fix NULL pointer dereference in process_metadata_update

The function process_metadata_update() blindly dereferences the 'thread' pointer (acquired via rcu_dereference_protected) within the wait_event() macro.

While the code comment states "daemon thread must exist", there is a valid race condition window during the MD array startup sequence (md_run):

  1. bitmap_load() is called, which invokes md_cluster_ops->join().
  2. join() starts the "cluster_recv" thread (recv_daemon).
  3. At this point, recv_daemon is active and processing messages.
  4. However, mddev->thread (the main MD thread) is not initialized until later in md_run().

If a METADATA_UPDATED message is received from a remote node during this specific window, process_metadata_update() will be called while mddev->thread is still NULL, leading to a kernel panic.

To fix this, we must validate the 'thread' pointer. If it is NULL, we release the held lock (no_new_dev_lockres) and return early, safely ignoring the update request as the array is not yet fully ready to process it.

CVSS Base Scores

version 3.1