Re: Security fix for remapping of page 0 (was [PATCH] Change ZERO_SIZE_PTR to point at unmapped space)

Eric Paris
2009-06-03T16:32:08Z

On Wed, Jun 3, 2009 at 12:28 PM, Linus Torvalds
<torvalds@linux-foundation.org> wrote:
>
>
> On Wed, 3 Jun 2009, Eric Paris wrote:
>>
>> As I recall the only need for CONFIG_SECURITY is for the ability to
>> override the check.
>
> No, if you have SECURITY disabled entirely, the check goes away.

I meant 'need' as in the reason I wrapped it in CONFIG_SECURITY, not
that you were wrong when you said it disapeared.

>> I think I could probably pretty cleanly change it to use
>> CAP_SYS_RAWIO/SELinux permissions if CONFIG_SECURITY and just allow it
>> for uid=0 in the non-security case?
>
> We probably should, since the "capability" security version should
> generally essentially emulate the regular non-SECURITY case for root.

Will poke/patch this afternoon.

-Eric