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Message-ID: <5e4e62c8-d17f-45fd-9212-088eb026dc7b@quicinc.com>
Date: Wed, 17 Apr 2024 14:51:38 +0800
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Subject: Re: [PATCH] Bluetooth: qca: Fix nullptr dereference for non-serdev
 devices
To: Johan Hovold <johan@kernel.org>
CC: <luiz.dentz@gmail.com>, <marcel@holtmann.org>,
        <linux-bluetooth@vger.kernel.org>, <johan+linaro@kernel.org>
References: <1713325792-17181-1-git-send-email-quic_zijuhu@quicinc.com>
 <Zh9saGbOl-fXP6SD@hovoldconsulting.com>
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From: quic_zijuhu <quic_zijuhu@quicinc.com>
In-Reply-To: <Zh9saGbOl-fXP6SD@hovoldconsulting.com>
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On 4/17/2024 2:30 PM, Johan Hovold wrote:
> On Wed, Apr 17, 2024 at 11:49:52AM +0800, Zijun Hu wrote:
>> hu->serdev is nullptr and will cause nullptr dereference if qca_setup()
>> is called by non-serdev device, fixed by null check before access.
> 
> No, this patch is not correct.
>  
i don't think so, nullptr checking for hu->serdev has been performed within qca_setup()
everywhere when need to access serdev related members since this function will be called 
by both serdev and none-serdev. so suggest add such checking.

>> Fixes: 77f45cca8bc5 ("Bluetooth: qca: fix device-address endianness")
>> Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
>> ---
>>  drivers/bluetooth/hci_qca.c | 9 +++++----
>>  1 file changed, 5 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
>> index 92fa20f5ac7d..9c6573c727e1 100644
>> --- a/drivers/bluetooth/hci_qca.c
>> +++ b/drivers/bluetooth/hci_qca.c
>> @@ -1905,10 +1905,11 @@ static int qca_setup(struct hci_uart *hu)
>>  	case QCA_WCN6750:
>>  	case QCA_WCN6855:
>>  	case QCA_WCN7850:
>> -		qcadev = serdev_device_get_drvdata(hu->serdev);
> 
> Non-serdev controllers have type QCA_ROME (see qca_soc_type()) so will
> never end up in this path.
> 
i have submitted below patches to add supports for all other non-serdev controllers.
https://patchwork.kernel.org/project/bluetooth/list/?series=844120

> I verified this when I wrote the patch and also fixed up a couple of
> real non-serdev bugs here:
> 
> 	https://lore.kernel.org/lkml/20240319154611.2492-1-johan+linaro@kernel.org/
>
actually, i have submitted below fix for this issue earlier.
https://lore.kernel.org/all/1704960978-5437-1-git-send-email-quic_zijuhu@quicinc.com/

>> -		if (qcadev->bdaddr_property_broken)
>> -			set_bit(HCI_QUIRK_BDADDR_PROPERTY_BROKEN, &hdev->quirks);
>> -
>> +		if (hu->serdev) {
>> +			qcadev = serdev_device_get_drvdata(hu->serdev);
>> +			if (qcadev->bdaddr_property_broken)
>> +				set_bit(HCI_QUIRK_BDADDR_PROPERTY_BROKEN, &hdev->quirks);
>> +		}
>>  		hci_set_aosp_capable(hdev);
>>  
>>  		ret = qca_read_soc_version(hdev, &ver, soc_type);
> 
> Johan