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

md/bitmap: fix GPF in write_page caused by resize race

A General Protection Fault occurs in write_page() during array resize:
RIP: 0010:write_page+0x22b/0x3c0 [md_mod]

This is a use-after-free race between bitmap_daemon_work() and
__bitmap_resize(). The daemon iterates over `bitmap->storage.filemap`
without locking, while the resize path frees that storage via
md_bitmap_file_unmap(). `quiesce()` does not stop the md thread,
allowing concurrent access to freed pages.

Fix by holding `mddev->bitmap_info.mutex` during the bitmap update.
Published: 2026-05-06
Score: n/a
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Impact

The Linux kernel md bitmap module contains a race condition between bitmap_daemon_work() and __bitmap_resize() that can trigger a general protection fault during write_page() when the bitmap storage is resized concurrently with the daemon iterating over the same memory. The missing mutex protection leads to a use‑after‑free, which results in an unhandled kernel crash and a system reboot. The flaw falls under CWE-416 and CWE-362.

Affected Systems

All Linux kernel releases that include the md bitmap module without the introduced mutex lock are affected. The data does not specify an exact version range; therefore any kernel that has not applied the patch that adds the mutex protection around the bitmap update is vulnerable. The modified code is part of the mainline kernel and will be present in all distributions that ship the corresponding kernel version.

Risk and Exploitability

The official score database does not provide a CVSS score and the EPSS score is reported as not available, so a numeric assessment of likelihood cannot be derived. Based on the description, it is inferred that the flaw can be triggered by a local user with sufficient privileges to manipulate block devices, such as an individual with root access or a process operating within a virtual machine that controls the block layer. The crash only occurs while the kernel is running, resulting in a local denial of service. The vulnerability is not currently listed in CISA’s KEV, but the presence of a kernel crash and lack of a hardening path suggest the risk is significant for impacted systems.

Generated by OpenCVE AI on May 6, 2026 at 14:16 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Upgrade the system to a kernel version that includes the patch adding the mutex protection in the md bitmap module.
  • Reboot the system to load the updated kernel.
  • If a kernel upgrade cannot be performed immediately, disable the bitmap resizing process by preventing the md bitmap module from operating on vulnerable block devices or by stopping the bitmap daemon service.
  • As a temporary compromise, ensure that no untrusted user space processes invoke bitmap resizing operations on affected devices.

Generated by OpenCVE AI on May 6, 2026 at 14:16 UTC.

Tracking

Sign in to view the affected projects.

Advisories

No advisories yet.

History

Wed, 06 May 2026 14:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-362
CWE-416

Wed, 06 May 2026 12:15:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: md/bitmap: fix GPF in write_page caused by resize race A General Protection Fault occurs in write_page() during array resize: RIP: 0010:write_page+0x22b/0x3c0 [md_mod] This is a use-after-free race between bitmap_daemon_work() and __bitmap_resize(). The daemon iterates over `bitmap->storage.filemap` without locking, while the resize path frees that storage via md_bitmap_file_unmap(). `quiesce()` does not stop the md thread, allowing concurrent access to freed pages. Fix by holding `mddev->bitmap_info.mutex` during the bitmap update.
Title md/bitmap: fix GPF in write_page caused by resize race
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-05-06T11:27:41.265Z

Reserved: 2026-05-01T14:12:55.990Z

Link: CVE-2026-43163

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-05-06T12:16:34.410

Modified: 2026-05-06T13:07:51.607

Link: CVE-2026-43163

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-06T14:30:05Z

Weaknesses