Re: [PATCH 9/9] serial: xuartps: Fix out-of-bounds access through DT alias

From: Michal Simek
Date: Tue Feb 20 2018 - 07:39:52 EST


On 20.2.2018 13:27, Geert Uytterhoeven wrote:
> Hi Michal,
>
> On Tue, Feb 20, 2018 at 12:27 PM, Michal Simek <michal.simek@xxxxxxxxxx> wrote:
>> On 20.2.2018 11:38, Geert Uytterhoeven wrote:
>>> On Tue, Feb 20, 2018 at 11:22 AM, Michal Simek <michal.simek@xxxxxxxxxx> wrote:
>>>> On 20.2.2018 10:40, Geert Uytterhoeven wrote:
>>>>> The cdns_uart_port[] array is indexed using a value derived from the
>>>>> "serialN" alias in DT, which may lead to an out-of-bounds access.
>>>>>
>>>>> Fix this by adding a range check.
>
>> I have checked 4 patches I have sent in past which didn't reach mainline
>> (probably because of RFC)
>> Take a look at
>> https://www.spinics.net/lists/linux-serial/msg27106.html
>>
>> I have removed cdns_uart_port array completely there.
>
> Nice! I'd love to get rid of fixed arrays in serial...
>
> However, IMHO it's still worthwhile to fix the out-of-bounds access first,
> as that fix can be backported to stable kernels easily.

I agree with you. Not a problem with your patch and for me it won't be
problem to rebase.

I would love to get rid of CDNS_UART_NR_PORTS but unfortunately this is
passed to core via .nr.

Thanks,
Michal