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Message-ID: <bf74d533-c0ff-42c6-966f-b4b28c5e0f60@molgen.mpg.de>
Date: Thu, 11 Jan 2024 10:46:34 +0100
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Subject: Re: [PATCH v1] Bluetooth: qca: Fix crash when btattach controller
 ROME
Content-Language: en-US
To: Zijun Hu <quic_zijuhu@quicinc.com>
Cc: luiz.dentz@gmail.com, marcel@holtmann.org, jiangzp@google.com,
 linux-bluetooth@vger.kernel.org, stable@vger.kernel.org
References: <1704960978-5437-1-git-send-email-quic_zijuhu@quicinc.com>
From: Paul Menzel <pmenzel@molgen.mpg.de>
In-Reply-To: <1704960978-5437-1-git-send-email-quic_zijuhu@quicinc.com>
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Dear Zijun,


Thank you for your patch.

Am 11.01.24 um 09:16 schrieb Zijun Hu:
> A crash will happen when btattach controller ROME, and it is caused by

What does “btattach controller ROME” mean? Is ROME a platform? If so, 
should it be *on ROME* or similar?

> dereferring nullptr hu->serdev, fixed by null check before access.

dereferring → dereferencing

> 
> 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@vger.kernel.org>
> Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
> Tested-by: Zijun Hu <quic_zijuhu@quicinc.com>

On what device?

> ---
>   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 94b8c406f0c0..6fcfc1f7bb12 100644
> --- a/drivers/bluetooth/hci_qca.c
> +++ b/drivers/bluetooth/hci_qca.c
> @@ -1951,7 +1951,7 @@ 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;

Why is `hu->serdev` not set on the device?

>   	} else if (ret == -ENOENT) {
>   		/* No patch/nvm-config found, run with original fw/config */


Kind regards,

Paul