Re: [PATCH] devcoredump: provide a one-way disable function

From: Kees Cook
Date: Thu Nov 13 2014 - 18:36:01 EST


On Thu, Nov 13, 2014 at 2:36 PM, Johannes Berg
<johannes@xxxxxxxxxxxxxxxx> wrote:
> On Thu, 2014-11-13 at 13:56 -0800, Kees Cook wrote:
>
>> > + /*
>> > + * This essentially makes the attribute write-once, since you can't
>> > + * go back to not having it disabled. This is intentional, it serves
>> > + * as a system lockdown feature.
>> > + */
>> > + if (tmp != 1)
>> > + return -EINVAL;
>>
>> Just a nit, but writing "0" is valid if devcd_disabled = false?
>
> I thought about that too, but what would the point be? The only
> operation you ever can/want to do is writing "1" to it to disable the
> framework.

Yup, seems like not a useful thing to do, but figured I'd point it out
just in case. I think the patch is fine as-is.

-Kees

--
Kees Cook
Chrome OS Security
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