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Date:   Mon, 30 Oct 2023 17:13:17 +0900 (JST)
Message-Id: <20231030.171317.1096475355592607869.syoshida@redhat.com>
To:     bvanassche@acm.org
Cc:     jejb@linux.ibm.com, martin.petersen@oracle.com,
        linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] scsi: sr: Fix a potential uninit-value in
 sr_get_events()
From:   Shigeru Yoshida <syoshida@redhat.com>
In-Reply-To: <c459dd2c-a281-7fc4-90cf-36a71e9548bc@acm.org>
References: <20230531164346.118438-1-syoshida@redhat.com>
        <c459dd2c-a281-7fc4-90cf-36a71e9548bc@acm.org>
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On Wed, 31 May 2023 15:44:17 -0700, Bart Van Assche wrote:
> On 5/31/23 09:43, Shigeru Yoshida wrote:
>> diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
>> index 12869e6d4ebd..86b43c069a44 100644
>> --- a/drivers/scsi/sr.c
>> +++ b/drivers/scsi/sr.c
>> @@ -177,10 +177,13 @@ static unsigned int sr_get_events(struct
>> scsi_device *sdev)
>>     	result = scsi_execute_cmd(sdev, cmd, REQ_OP_DRV_IN, buf, sizeof(buf),
>>   				  SR_TIMEOUT, MAX_RETRIES, &exec_args);
>> +	if (result)
>> +		return 0;
>> +
>>   	if (scsi_sense_valid(&sshdr) && sshdr.sense_key == UNIT_ATTENTION)
>>   		return DISK_EVENT_MEDIA_CHANGE;
>>   -	if (result || be16_to_cpu(eh->data_len) < sizeof(*med))
>> +	if (be16_to_cpu(eh->data_len) < sizeof(*med))
>>   		return 0;
> 
> I think this change is wrong because it introduces an unintended
> behavior
> change. A better solution is probably to zero-initialize sshdr before
> scsi_execute_cmd() is called.

Hi Bart,

I'm very sorry for the very late response, and thank you so much for
your feedback. I'll prepare the v2 patch as you suggested.

Thanks,
Shigeru

> 
> Thanks,
> 
> Bart.
>