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Subject: Re: [PATCH] staging: greybus: Fix null pointer dereference
To:     Johan Hovold <johan@kernel.org>
Cc:     elder@kernel.org, gregkh@linuxfoundation.org,
        greybus-dev@lists.linaro.org, devel@driverdev.osuosl.org,
        linux-kernel@vger.kernel.org,
        Viresh Kumar <viresh.kumar@linaro.org>
References: <1535083631-1892-1-git-send-email-dingxiang@cmss.chinamobile.com>
 <20180824062930.GS14967@localhost>
From:   Ding Xiang <dingxiang@cmss.chinamobile.com>
Message-ID: <e7ff8e83-1982-a0bc-e959-2657adf0647e@cmss.chinamobile.com>
Date:   Fri, 24 Aug 2018 18:08:39 +0800
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Hi, Johan

     sorry, it's my fault.


On 8/24/2018 2:29 PM, Johan Hovold wrote:
> On Fri, Aug 24, 2018 at 12:07:11AM -0400, Ding Xiang wrote:
>> If fw is null then fw->size will trigger null pointer dereference
>>
>> Signed-off-by: Ding Xiang <dingxiang@cmss.chinamobile.com>
>> ---
>>   drivers/staging/greybus/bootrom.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/staging/greybus/bootrom.c b/drivers/staging/greybus/bootrom.c
>> index e85ffae..3af28a0 100644
>> --- a/drivers/staging/greybus/bootrom.c
>> +++ b/drivers/staging/greybus/bootrom.c
>> @@ -297,7 +297,7 @@ static int gb_bootrom_get_firmware(struct gb_operation *op)
>>   
>>   queue_work:
>>   	/* Refresh timeout */
>> -	if (!ret && (offset + size == fw->size))
>> +	if (!ret && fw && (offset + size == fw->size))
>>   		next_request = NEXT_REQ_READY_TO_BOOT;
>>   	else
>>   		next_request = NEXT_REQ_GET_FIRMWARE;
> How could fw be NULL when ret is 0 here?
>
> It may not be as obvious as one might have wished, but the current code
> looks correct to me.
>
> Johan
>