Re: [PATCH] xen/memory: Reject out-of-range resource 'frame' values

[Jan Beulich <jbeulich@xxxxxxxx>]

On 29.01.2021 11:04, Andrew Cooper wrote:
> On 29/01/2021 10:01, Jan Beulich wrote:
>> On 29.01.2021 10:47, Andrew Cooper wrote:
>>> On 29/01/2021 09:40, Jan Beulich wrote:
>>>> On 29.01.2021 10:32, Andrew Cooper wrote:
>>>>> What's the likelihood that you'll choose to backport this?
>>>> Didn't consider this aspect yet. I think I wouldn't have picked
>>>> it without anyone asking for it to be backported.
>>>>
>>>>>   I can extend it if needs be.
>>>> Well, if that deletion of code gets committed in time, then of
>>>> course there's no real need to fiddle with it here.
>>> This specific patch fixes a real bug on arm32 which will cause unsigned
>>> long + unsigned int to truncate together and permit certain values.
>> Why Arm32 only? Looking at current staging, there's no overflow
>> check at all on the grant part of the path. A suitably large
>> 64-bit "frame" will allow the same behavior on 64-bit (wrapping
>> around through zero), afaict.
> 
> Very good point.  I'd worked the logic through logically at the end of
> my fixes, rather than at its position in the beginning of the series.
> 
> In which case I'll propagate through the whole call-tree.

Thanks. And then, as said,
Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>

And I guess I'll try to remember to pick this up for backporting
once it has landed.

Jan