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.
References
Configurations
Configuration 1 (hide)
|
History
08 May 2026, 20:00
| Type | Values Removed | Values Added |
|---|---|---|
| First Time |
Linux linux Kernel
Linux |
|
| CWE | CWE-476 | |
| CPE | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 5.5 |
| References | () https://git.kernel.org/stable/c/721599e837d3f4c0e6cc14da059612c017b6d3ec - Patch | |
| References | () https://git.kernel.org/stable/c/a61c1bc84c4a0f1e7c2fe55b0f43d7d94af4adf1 - Patch | |
| References | () https://git.kernel.org/stable/c/dceb5a843910004cb118148e267036104fc3ee43 - Patch | |
| References | () https://git.kernel.org/stable/c/dec123825c1ed74d98fd5fc7571a851dea4f46ff - Patch | |
| References | () https://git.kernel.org/stable/c/f150e753cb8dd756085f46e86f2c35ce472e0a3c - Patch |
06 May 2026, 12:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-05-06 12:16
Updated : 2026-05-08 20:00
NVD link : CVE-2026-43271
Mitre link : CVE-2026-43271
CVE.ORG link : CVE-2026-43271
JSON object : View
Products Affected
linux
- linux_kernel
CWE
CWE-476
NULL Pointer Dereference