Re: [PATCH] phy: ocelot-serdes: fix out-of-bounds read

From: Gustavo A. R. Silva
Date: Mon Oct 08 2018 - 17:02:36 EST


Hey Quentin,

On 10/8/18 10:55 PM, Quentin Schulz wrote:
> Hi Gustavo,
>
> On Mon, Oct 08, 2018 at 08:06:49PM +0200, Gustavo A. R. Silva wrote:
>> Currently, there is an out-of-bounds read on array ctrl->phys,
>> once variable i reaches the maximum array size of SERDES_MAX
>> in the for loop.
>>
>> Fix this by changing the condition in the for loop from
>> i <= SERDES_MAX to i < SERDES_MAX.
>>
>
> Thanks for the heads up. However, as defined today, SERDES_MAX is a
> valid value so I need it in the iteration. There are two possible fixes
> though:
>

Oh okay. I've got it.

> Either we let all the for loops as `for (i = 0; i <= SERDES_MAX; i++)`
> and define ctrl->phys as an array of size SERDES_MAX + 1.
>
> Or we modify the for loops as `for (i = 0; i < SERDES_MAX; i++)` and we
> update SERDES_MAX in include/dt-bindings/phy/phy-ocelot-serdes.h to be
> SERDES6G_MAX + 1.
>

I think this one is better.

> As you wish!
>

I'll send v2 shortly.

Thanks for the feedback. :)
--
Gustavo