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

["Wu, Songjun" <Songjun.Wu@microchip.com>]

On 3/9/2017 19:50, Colin Ian King wrote:
> On 09/03/17 11:49, walter harms wrote:
>>
>>
>> Am 09.03.2017 11:57, schrieb Hans Verkuil:
>>> 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.
>>>
>>> Regards,
>>>
>>> 	Hans
>>>
>>
>>
>>
>> perhaps he will make it a bit more readable, like:
>>
>> *hist_count += i * (*hist_entry++);
>>
>> *hist_count += hist_entry[i]*i;
>
> As long as it gets fixed somehow, then I'm happy.
>
You suggestion is very good, I will modify it like this.
Thank you.

> Colin
>>
>>
>> re,
>>  wh
>>>>
>>>> On 3/7/2017 22:30, Colin King wrote:
>>>>> From: Colin Ian King <colin.king@canonical.com>
>>>>>
>>>>> 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@canonical.com>
>>>>> ---
>>>>>  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++);
>>>>>  }
>>>>>
>>>>>
>>>
>>
>>
>>
>>
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>