A crash will happen when use tool btattach to attach a BT controller QCA_ROME, and it is caused by dereferencing nullptr hu->serdev, fixed by null check before access. sudo btattach -B /dev/ttyUSB0 -P qca Bluetooth: hci1: QCA setup on UART is completed BUG: kernel NULL pointer dereference, address: 00000000000002f0 ...... Workqueue: hci1 hci_power_on [bluetooth] RIP: 0010:qca_setup+0x7c1/0xe30 [hci_uart] ...... Call Trace: <TASK> ? show_regs+0x72/0x90 ? __die+0x25/0x80 ? page_fault_oops+0x154/0x4c0 ? srso_alias_return_thunk+0x5/0xfbef5 ? kmem_cache_alloc+0x16b/0x310 ? do_user_addr_fault+0x330/0x6e0 ? srso_alias_return_thunk+0x5/0xfbef5 ? exc_page_fault+0x84/0x1b0 ? asm_exc_page_fault+0x27/0x30 ? qca_setup+0x7c1/0xe30 [hci_uart] hci_uart_setup+0x5c/0x1a0 [hci_uart] hci_dev_open_sync+0xee/0xca0 [bluetooth] hci_dev_do_open+0x2a/0x70 [bluetooth] hci_power_on+0x46/0x210 [bluetooth] process_one_work+0x17b/0x360 worker_thread+0x307/0x430 ? __pfx_worker_thread+0x10/0x10 kthread+0xf7/0x130 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x46/0x70 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1b/0x30 </TASK> Fixes: 03b0093f7b31 ("Bluetooth: hci_qca: get wakeup status from serdev device handle") Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Zijun Hu <quic_zijuhu@xxxxxxxxxxx> Tested-by: Zijun Hu <quic_zijuhu@xxxxxxxxxxx> --- drivers/bluetooth/hci_qca.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c index 92fa20f5ac7d..fdaf83d817af 100644 --- a/drivers/bluetooth/hci_qca.c +++ b/drivers/bluetooth/hci_qca.c @@ -1955,7 +1955,7 @@ static int qca_setup(struct hci_uart *hu) qca_debugfs_init(hdev); hu->hdev->hw_error = qca_hw_error; hu->hdev->cmd_timeout = qca_cmd_timeout; - if (device_can_wakeup(hu->serdev->ctrl->dev.parent)) + if (hu->serdev && device_can_wakeup(hu->serdev->ctrl->dev.parent)) hu->hdev->wakeup = qca_wakeup; } else if (ret == -ENOENT) { /* No patch/nvm-config found, run with original fw/config */ -- 2.7.4