Re: [PATCH v2 4/4] venus: hfi_parser: Add check to keep the number of codecs within range

[Vikash Garodia <quic_vgarodia@quicinc.com>]

On 8/11/2023 2:12 PM, Bryan O'Donoghue wrote:
> On 11/08/2023 07:04, Vikash Garodia wrote:
>>
>> On 8/10/2023 5:03 PM, Bryan O'Donoghue wrote:
>>> On 10/08/2023 03:25, Vikash Garodia wrote:
>>>> +    if (hweight_long(core->dec_codecs) + hweight_long(core->enc_codecs) >
>>>> MAX_CODEC_NUM)
>>>> +        return;
>>>> +
>>>
>>> Shouldn't this be >= ?
>> Not needed. Lets take a hypothetical case when core->dec_codecs has initial 16
>> (0-15) bits set and core->enc_codecs has next 16 bits (16-31) set. The bit count
>> would be 32. The codec loop after this check would run on caps array index 0-31.
>> I do not see a possibility for OOB access in this case.
>>
>>>
>>> struct hfi_plat_caps caps[MAX_CODEC_NUM];
>>>
>>> ---
>>> bod
>>>
> 
> Are you not doing a general defensive coding pass in this series ie
> 
> "[PATCH v2 2/4] venus: hfi: fix the check to handle session buffer requirement"

In "PATCH v2 2/4", there is a possibility if the check does not consider "=".
Here in this patch, I do not see a possibility.

> 
> ---
> bod