CVE-2026-43119: Bluetooth: hci_sync: annotate data-races around hdev->req_status

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-06 · updated 2026-10-30

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_sync: annotate data-races around hdev->req_status __hci_cmd_sync_sk() sets hdev->req_status under hdev->req_lock: hdev->req_status = HCI_REQ_PEND; However, several other functions read or write hdev->req_status without holding any lock: - hci_send_cmd_sync() reads req_status in hci_cmd_work (workqueue) - hci_cmd_sync_complete() reads/writes from HCI event completion - hci_cmd_sync_cancel() / hci_cmd_sync_cancel_sync() read/write - hci_abort_conn() reads in connection abort path Since __hci_cmd_sync_sk() runs on hdev->req_workqueue while hci_send_cmd_sync() runs on hdev->workqueue, these are different workqueues that can execute concurrently on different CPUs. The plain C accesses constitute a data race. Add READ_ONCE()/WRITE_ONCE() annotations on all concurrent accesses to hdev->req_status to prevent potential compiler optimizations that could affect correctness (e.g., load fusing in the wait_event condition or store reordering).

Affected products

Linux kernel: from 5.2 before 6.12.83; from 6.13 before 6.18.24; from 6.19 before 6.19.14; 7.0-rc1, 7.0-rc2, 7.0-rc3, 7.0-rc4, 7.0-rc5 — fixed in 6.12.83, 6.18.24, 6.19.14
Linux: from 4.19.47 before 4.20; from 5.0.20 before 5.1; from 5.1.6 before 5.2 — fixed in 4.20, 5.1, 5.2

How to fix

Upgrade to a fixed version: Linux kernel 6.12.83, 6.18.24, 6.19.14; Linux 4.20, 5.1, 5.2. Check the vendor advisory for mitigations.

References

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