CVE-2024-41063: Bluetooth: hci_core: cancel all works upon hci_unregister_dev()

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-07-29 · updated 2026-06-17
Weakness: CWE-667

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_core: cancel all works upon hci_unregister_dev() syzbot is reporting that calling hci_release_dev() from hci_error_reset() due to hci_dev_put() from hci_error_reset() can cause deadlock at destroy_workqueue(), for hci_error_reset() is called from hdev->req_workqueue which destroy_workqueue() needs to flush. We need to make sure that hdev->{rx_work,cmd_work,tx_work} which are queued into hdev->workqueue and hdev->{power_on,error_reset} which are queued into hdev->req_workqueue are no longer running by the moment destroy_workqueue(hdev->workqueue); destroy_workqueue(hdev->req_workqueue); are called from hci_release_dev(). Call cancel_work_sync() on these work items from hci_unregister_dev() as soon as hdev->list is removed from hci_dev_list.

Affected products

Linux kernel: before 4.19.319; from 4.20 before 5.4.281; from 5.5 before 5.10.223; from 5.11 before 5.15.164; from 5.16 before 6.1.101; from 6.2 before 6.6.42 — fixed in 4.19.319, 5.10.223, 5.15.164, 5.4.281, 6.1.101, 6.6.42

How to fix

Upgrade to a fixed version: Linux kernel 4.19.319, 5.10.223, 5.15.164, 5.4.281. Check the vendor advisory for mitigations.

References

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