[dm-devel] limits->max_sectors is getting set to 0, why/where? [was: Re: dm: kernel oops by divide error on v4.16+]

[Jens Axboe]

On 4/9/18 4:38 PM, Kees Cook wrote:
> On Mon, Apr 9, 2018 at 3:32 PM, Jens Axboe <axboe at kernel.dk> wrote:
>> That's bad, for sure, but my worry was bigger than an oops or crash,
>> we could have had corruption due to this.
>>
>> The resulting min/max and friends would have been trivial to test, but
>> clearly they weren't.
> 
> Yeah, that was bad luck and my fault: I tested min(), max(), min_t(),

It's only bad luck if it was tested :-)

> and max_t(). My assumption was that since the others were built from
> them, they'd be fine. Not true in this shadow variable case, though.
> :(  We could do something like this, which would have caught it:

Might not hurt to do.

-- 
Jens Axboe