linux-kernel - Re: [PATCH] media: pci: mgb4: Fix timings comparison in VIDIOC_S_DV

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <a486ae80-b53f-4f8c-b7d9-38d51f793981@gpxsee.org>
Date: Mon, 25 Aug 2025 17:22:34 +0200
From: Martin Tůma <tumic@...see.org>
To: Hans Verkuil <hverkuil+cisco@...nel.org>,
 Mauro Carvalho Chehab <mchehab@...nel.org>, Hans Verkuil <hverkuil@...all.nl>
Cc: linux-media@...r.kernel.org, linux-kernel@...r.kernel.org,
 Martin Tůma <martin.tuma@...iteqautomotive.com>
Subject: Re: [PATCH] media: pci: mgb4: Fix timings comparison in
 VIDIOC_S_DV_TIMINGS

On 8/25/25 5:03 PM, Hans Verkuil wrote:
> On 04/08/2025 11:20, tumic@...see.org wrote:
>> From: Martin Tůma <martin.tuma@...iteqautomotive.com>
>>
>> Compare the whole v4l2_bt_timings struct, not just the width/height when
>> setting new timings. Timings with the same resolution and different
>> pixelclock can now be properly set.
>>
>> Signed-off-by: Martin Tůma <martin.tuma@...iteqautomotive.com>
>> ---
>>   drivers/media/pci/mgb4/mgb4_vin.c | 4 ++--
>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/media/pci/mgb4/mgb4_vin.c b/drivers/media/pci/mgb4/mgb4_vin.c
>> index 989e93f67f75..15182549d108 100644
>> --- a/drivers/media/pci/mgb4/mgb4_vin.c
>> +++ b/drivers/media/pci/mgb4/mgb4_vin.c
>> @@ -610,8 +610,8 @@ static int vidioc_s_dv_timings(struct file *file, void *fh,
>>   	    timings->bt.height < video_timings_cap.bt.min_height ||
>>   	    timings->bt.height > video_timings_cap.bt.max_height)
>>   		return -EINVAL;
>> -	if (timings->bt.width == vindev->timings.bt.width &&
>> -	    timings->bt.height == vindev->timings.bt.height)
>> +	if (!memcmp(&timings->bt, &vindev->timings.bt,
>> +		    sizeof(struct v4l2_bt_timings)))
> 
> I would recommend calling v4l2_match_dv_timings() instead.
> Otherwise you would also match on the reserved fields and 'standards'
> and 'flags' fields.
> 

Yes, that's definitely better. I will post a v2 with this change 
tomorrow. Thanks for pointing this out.

M.

> Regards,
> 
> 	Hans
> 
>>   		return 0;
>>   	if (vb2_is_busy(&vindev->queue))
>>   		return -EBUSY;
>>
>> base-commit: d968e50b5c26642754492dea23cbd3592bde62d8
>