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.
Fix
Patch, vendor advisory and mitigation references on NVD 7
- https://git.kernel.org/stable/c/03e8c90c62233382042b7bd0fa8b8900552fdb62 Patch
- https://git.kernel.org/stable/c/0c3cd7a0b862c37acbee6d9502107146cc944398 Patch
- https://git.kernel.org/stable/c/186d147cf7689ba1f9b3ddb753ab634a84940cc9 Patch
- https://git.kernel.org/stable/c/53e54cb31e667fca05b1808b990eac0807d1dab0 Patch
- https://git.kernel.org/stable/c/937a573423ce5a96fdb1fd425dc6b8d8d4ab5779 Patch
- https://git.kernel.org/stable/c/b0a900939e7e4866d9b90e9112514b72c451e873 Patch
- https://git.kernel.org/stable/c/ccc683f597ceb28deb966427ae948e5ac739a909 Patch
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 5.5 · linuxNVD modified 2026-10-19 19:17
Affected (CPE criteria) 8
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:6.19:rc1:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:6.19:rc2:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:6.19:rc3:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:6.19:rc4:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:6.19:rc5:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:6.19:rc6:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:6.19:rc7:*:*:*:*:*:*
References 7
- https://git.kernel.org/stable/c/03e8c90c62233382042b7bd0fa8b8900552fdb62 Patch
- https://git.kernel.org/stable/c/0c3cd7a0b862c37acbee6d9502107146cc944398 Patch
- https://git.kernel.org/stable/c/186d147cf7689ba1f9b3ddb753ab634a84940cc9 Patch
- https://git.kernel.org/stable/c/53e54cb31e667fca05b1808b990eac0807d1dab0 Patch
- https://git.kernel.org/stable/c/937a573423ce5a96fdb1fd425dc6b8d8d4ab5779 Patch
- https://git.kernel.org/stable/c/b0a900939e7e4866d9b90e9112514b72c451e873 Patch
- https://git.kernel.org/stable/c/ccc683f597ceb28deb966427ae948e5ac739a909 Patch