Re: [PATCH] [media] atmel-isc: fix off-by-one comparison and out of bounds read issue

[Hans Verkuil]

On 03/13/2017 10:32 AM, Wu, Songjun wrote:
> 
> 
> On 3/13/2017 17:25, Hans Verkuil wrote:
>> On 03/13/2017 06:53 AM, Wu, Songjun wrote:
>>>
>>>
>>> On 3/9/2017 18:57, Hans Verkuil wrote:
>>>> Hi Songjun,
>>>>
>>>> On 08/03/17 03:25, Wu, Songjun wrote:
>>>>> Hi Colin,
>>>>>
>>>>> Thank you for your comment.
>>>>> It is a bug, will be fixed in the next patch.
>>>>
>>>> Do you mean that you will provide a new patch for this? Is there anything
>>>> wrong with this patch? It seems reasonable to me.
>>>>
>>> Hi Hans,
>>>
>>> I see this patch is merged in git://linuxtv.org/media_tree.git.
>>> So I do not need submit isc-pipeline-v3 patch, just submit the patches,
>>> based on the current master branch?
>>
>> Huh? Where do you see that this patch is merged? I don't see it in the media_tree master
>> branch.
>>
> Hi Hans,
> 
> I see this patch on the master branch in media_tree.
> https://git.linuxtv.org/media_tree.git/tree/drivers/media/platform/atmel/atmel-isc.c

???

That's a link to the source, not a patch.

And that source still does <= HIST_ENTRIES.

Still confused,

	Hans

> 
>> Regards,
>>
>> 	Hans
>>
>>>
>>>> Regards,
>>>>
>>>> 	Hans
>>>>
>>>>>
>>>>> On 3/7/2017 22:30, Colin King wrote:
>>>>>> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
>>>>>>
>>>>>> The are only HIST_ENTRIES worth of entries in  hist_entry however the
>>>>>> for-loop is iterating one too many times leasing to a read access off
>>>>>> the end off the array ctrls->hist_entry.  Fix this by iterating by
>>>>>> the correct number of times.
>>>>>>
>>>>>> Detected by CoverityScan, CID#1415279 ("Out-of-bounds read")
>>>>>>
>>>>>> Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
>>>>>> ---
>>>>>>  drivers/media/platform/atmel/atmel-isc.c | 2 +-
>>>>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>>>>
>>>>>> diff --git a/drivers/media/platform/atmel/atmel-isc.c b/drivers/media/platform/atmel/atmel-isc.c
>>>>>> index b380a7d..7dacf8c 100644
>>>>>> --- a/drivers/media/platform/atmel/atmel-isc.c
>>>>>> +++ b/drivers/media/platform/atmel/atmel-isc.c
>>>>>> @@ -1298,7 +1298,7 @@ static void isc_hist_count(struct isc_device *isc)
>>>>>>      regmap_bulk_read(regmap, ISC_HIS_ENTRY, hist_entry, HIST_ENTRIES);
>>>>>>
>>>>>>      *hist_count = 0;
>>>>>> -    for (i = 0; i <= HIST_ENTRIES; i++)
>>>>>> +    for (i = 0; i < HIST_ENTRIES; i++)
>>>>>>          *hist_count += i * (*hist_entry++);
>>>>>>  }
>>>>>>
>>>>>>
>>>>
>>