Re: [PATCH] KERNEL: resource: Fix bug on leakage in /proc/iomem file

[Emrah Demir <ed@abdsec.com>]

On 2016-04-14 00:27, Kees Cook wrote:
> On Wed, Apr 6, 2016 at 2:19 PM, Linus Torvalds
> <torvalds@linux-foundation.org> wrote:
>> On Wed, Apr 6, 2016 at 10:54 AM, Linus Torvalds
>> <torvalds@linux-foundation.org> wrote:
>>> 
>>> So I'd find a patch like the attached to be perfectly acceptable (in
>>> fact, we should have done this long ago).
>> 
>> I just committed it, let's see if some odd program uses the iomem
>> data. I doubt it, and I always enjoy improvements that remove more
>> lines of code than they add.
> 
> Hrm, it looks like at least Ubuntu's kernel security test suite
> expects to find these entries (when it verifies that STRICT_DEVMEM
> hasn't regressed). Also, the commit only removed the entries on x86.
> Most (all?) of the other architectures still have them. Could you
> revert this for now, and I'll cook up a %pK-based solution for -next?
> 

Actually, I have realized that this patch (Linus's patch) was for x86. I 
was planning to code the same for other architectures.
It seems your method is better. %pK will zero other values in 
/proc/iomem.

Perhaps Ubuntu patch might be a good option.