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

On 20.2.2018 13:27, Geert Uytterhoeven wrote:

Hi Michal,

On Tue, Feb 20, 2018 at 12:27 PM, Michal Simek [off-list ref] wrote:

quoted

On 20.2.2018 11:38, Geert Uytterhoeven wrote:

quoted

On Tue, Feb 20, 2018 at 11:22 AM, Michal Simek [off-list ref] wrote:

quoted

On 20.2.2018 10:40, Geert Uytterhoeven wrote:

quoted

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.

quoted

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