CVE-2022-50833
Unknown Unknown - Not Provided
Race Condition in Linux Bluetooth Workqueue Causes Potential Deadlock

Publication date: 2025-12-30

Last updated on: 2025-12-30

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: use hdev->workqueue when queuing hdev->{cmd,ncmd}_timer works syzbot is reporting attempt to schedule hdev->cmd_work work from system_wq WQ into hdev->workqueue WQ which is under draining operation [1], for commit c8efcc2589464ac7 ("workqueue: allow chained queueing during destruction") does not allow such operation. The check introduced by commit 877afadad2dce8aa ("Bluetooth: When HCI work queue is drained, only queue chained work") was incomplete. Use hdev->workqueue WQ when queuing hdev->{cmd,ncmd}_timer works because hci_{cmd,ncmd}_timeout() calls queue_work(hdev->workqueue). Also, protect the queuing operation with RCU read lock in order to avoid calling queue_delayed_work() after cancel_delayed_work() completed.
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Meta Information
Published
2025-12-30
Last Modified
2025-12-30
Generated
2026-05-07
AI Q&A
2025-12-30
EPSS Evaluated
2026-05-05
NVD
EUVD
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
linux linux_kernel *
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-UNKNOWN
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AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability in the Linux kernel's Bluetooth component involves improper handling of workqueue operations. Specifically, there was an attempt to schedule Bluetooth device command work (hdev->cmd_work) from the system workqueue into the device's own workqueue while it was being drained, which is not allowed. The existing check to prevent this was incomplete. The fix involves using the correct workqueue (hdev->workqueue) for queuing command timer works and protecting the queuing operation with an RCU read lock to avoid queuing work after cancellation has completed.


How can this vulnerability impact me? :

This vulnerability could lead to improper scheduling of Bluetooth workqueue tasks, potentially causing system instability or unexpected behavior in Bluetooth operations within the Linux kernel. This might result in crashes or degraded Bluetooth functionality.


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