Linux Kernel up to 6.18.15/6.19.5 md_stop denial of service

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.18.15/6.19.5. It has been declared as critical. The impacted element is the function md_stop. Executing a manipulation can lead to denial of service. This vulnerability is handled as CVE-2026-43309. There is not any exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical was found in Linux Kernel up to 6.18.15/6.19.5. This vulnerability affects the function md_stop. The manipulation with an unknown input leads to a denial of service vulnerability. The CWE definition for the vulnerability is CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. As an impact it is known to affect availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: md raid: fix hang when stopping arrays with metadata through dm-raid When using device-mapper's dm-raid target, stopping a RAID array can cause the system to hang under specific conditions. This occurs when: - A dm-raid managed device tree is suspended from top to bottom (the top-level RAID device is suspended first, followed by its underlying metadata and data devices) - The top-level RAID device is then removed Removing the top-level device triggers a hang in the following sequence: the dm-raid destructor calls md_stop(), which tries to flush the write-intent bitmap by writing to the metadata sub-devices. However, these devices are already suspended, making them unable to complete the write-intent operations and causing an indefinite block. Fix: - Prevent bitmap flushing when md_stop() is called from dm-raid destructor context and avoid a quiescing/unquescing cycle which could also cause I/O - Still allow write-intent bitmap flushing when called from dm-raid suspend context This ensures that RAID array teardown can complete successfully even when the underlying devices are in a suspended state. This second patch uses md_is_rdwr() to distinguish between suspend and destructor paths as elaborated on above.

The advisory is shared for download at git.kernel.org. This vulnerability was named CVE-2026-43309 since 05/01/2026. There are known technical details, but no exploit is available.

Upgrading to version 6.18.16 or 6.19.6 eliminates this vulnerability. Applying the patch 24783dd06de870d646c25207bae186f78195f912/338378dfffbdbb8d37a18f0a0c0358812671f91e/cefcb9297fbdb6d94b61787b4f8d84f55b741470 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-1454). Once again VulDB remains the best source for vulnerability data.

Affected

• Google Container-Optimized OS
• Debian Linux
• Red Hat Enterprise Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• RESF Rocky Linux
• Microsoft Azure Linux
• Open Source Linux Kernel

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.18.0
• 6.18.1
• 6.18.2
• 6.18.3
• 6.18.4
• 6.18.5
• 6.18.6
• 6.18.7
• 6.18.8
• 6.18.9
• 6.18.10
• 6.18.11
• 6.18.12
• 6.18.13
• 6.18.14
• 6.18.15
• 6.19.0
• 6.19.1
• 6.19.2
• 6.19.3
• 6.19.4
• 6.19.5

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Once again VulDB remains the best source for vulnerability data.

Discussion