Re: [PATCH] x86/sysctl: Don't clobber memory if NCAPINTS > ARRAY_SIZE(pi->hw_cap)

[Ian Campbell <ian.campbell@citrix.com>]

On Wed, 2015-09-16 at 16:01 +0100, Wei Liu wrote:
> On Wed, Sep 16, 2015 at 10:01:45AM +0100, Andrew Cooper wrote:
> > There is no current problem, as both NCAPINTS and pi->hw_cap are 8
> > entries,
> > but the limit should be calculated appropriately so as to avoid
> > hypervisor
> > stack corruption if the two do get out of sync.
> > 
> > Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
> > ---
> > CC: Jan Beulich <JBeulich@suse.com>
> > CC: Wei Liu <wei.liu2@citrix.com>
> > 
> > I came across this during my cpuid levelling work.  As I know I am not
> > the
> > only person playing with NCAPINTS at the moment, I am posting this
> > ahead of
> > the rest of the work.
> > 
> > Wei: Concerning 4.6, it might we worth taking this, as it will likely
> > bite
> > downstream distributers who backport a 4.7 feature.
> > 
> 
> Release-acked-by: Wei Liu <wei.liu2@citrix.com>

Andy tells me that Jan is away so I have cherry-picked this
(c373b912e74659f0e0898ae93e89513694cfd94e) to staging-4.6 at his request.

Ian.