CVE-2026-43340
Received Received - Intake
Race Condition in Linux Kernel COMEDI Subsystem

Publication date: 2026-05-08

Last updated on: 2026-05-08

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: comedi: Reinit dev->spinlock between attachments to low-level drivers `struct comedi_device` is the main controlling structure for a COMEDI device created by the COMEDI subsystem. It contains a member `spinlock` containing a spin-lock that is initialized by the COMEDI subsystem, but is reserved for use by a low-level driver attached to the COMEDI device (at least since commit 25436dc9d84f ("Staging: comedi: remove RT code")). Some COMEDI devices (those created on initialization of the COMEDI subsystem when the "comedi.comedi_num_legacy_minors" parameter is non-zero) can be attached to different low-level drivers over their lifetime using the `COMEDI_DEVCONFIG` ioctl command. This can result in inconsistent lock states being reported when there is a mismatch in the spin-lock locking levels used by each low-level driver to which the COMEDI device has been attached. Fix it by reinitializing `dev->spinlock` before calling the low-level driver's `attach` function pointer if `CONFIG_LOCKDEP` is enabled.
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Meta Information
Published
2026-05-08
Last Modified
2026-05-08
Generated
2026-05-09
AI Q&A
2026-05-08
EPSS Evaluated
N/A
NVD
EUVD
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
comedi comedi *
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-UNKNOWN
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability exists in the Linux kernel's COMEDI subsystem, specifically involving the handling of a spin-lock within the comedi_device structure. The spin-lock is intended for use by low-level drivers attached to a COMEDI device. However, when a COMEDI device is attached to different low-level drivers over its lifetime using the COMEDI_DEVCONFIG ioctl command, inconsistent lock states can occur if the spin-lock locking levels differ between these drivers. This inconsistency can lead to incorrect lock state reporting. The vulnerability is addressed by reinitializing the spin-lock before attaching a new low-level driver if CONFIG_LOCKDEP is enabled.


How can this vulnerability impact me? :

The impact of this vulnerability is related to potential inconsistencies in lock states within the COMEDI subsystem when switching between different low-level drivers. Such inconsistencies could lead to unpredictable behavior or race conditions in device handling, potentially causing system instability or incorrect operation of COMEDI devices.


What immediate steps should I take to mitigate this vulnerability?

The vulnerability is fixed by reinitializing the spinlock (dev->spinlock) before calling the low-level driver's attach function pointer if CONFIG_LOCKDEP is enabled.

Therefore, to mitigate this vulnerability, ensure your Linux kernel is updated to a version that includes this fix.


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