Bug 2466991 (CVE-2026-43119)

Summary: CVE-2026-43119 kernel: Bluetooth: hci_sync: annotate data-races around hdev->req_status
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Doc Text:
A flaw was found in the Linux kernel Bluetooth HCI synchronous command infrastructure. Several paths read or wrote `hdev->req_status` without coordination while `__hci_cmd_sync_sk()` updates it under `req_lock`, and different workqueues could run those paths concurrently—creating data races that break wait/event correctness. Upstream documents the races and uses READ_ONCE()/WRITE_ONCE() on all concurrent accesses to `hdev->req_status`.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-05-06 10:02:09 UTC
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).