Re: [PATCH 5/6] notifiers: Use CHECK_DATA_CORRUPTION() on checks

From: Kees Cook
Date: Wed Mar 22 2017 - 15:55:46 EST


On Wed, Mar 22, 2017 at 12:32 PM, Arjan van de Ven
<arjan@xxxxxxxxxxxxxxx> wrote:
> On 3/22/2017 12:29 PM, Kees Cook wrote:
>>>
>>> When performing notifier function pointer sanity checking, allow
>>> CONFIG_BUG_ON_DATA_CORRUPTION to upgrade from a WARN to a BUG.
>>> Additionally enables CONFIG_DEBUG_NOTIFIERS when selecting
>>> CONFIG_BUG_ON_DATA_CORRUPTION.
>
>
>> Any feedback on this change? By default, this retains the existing
>> WARN behavior...
>
>
> if you're upgrading, is the end point really a panic() ?
> e.g. do you assume people to also set panic-on-oops?

That's one option, yes. With the BUG, the process associated is killed
(which is the first level of defense upgrade), and if a system is also
set to panic-on-oops, the entire system will panic (and usually such
systems also retain their crash consoles in some fashion for later
analysis, etc).

-Kees

--
Kees Cook
Pixel Security