Re: [kernel-hardening] [PATCH v3 0/5] bug: Provide toggle for BUG on data corruption

Paul E. McKenney
2016-08-19T01:22:10Z

On Thu, Aug 18, 2016 at 01:42:55PM -0400, Rik van Riel wrote:
> On Wed, 2016-08-17 at 14:42 -0700, Kees Cook wrote:
> > This adds CONFIG_BUG_ON_DATA_CORRUPTION to trigger BUG()s when the
> > kernel
> > encounters unexpected data structure integrity as currently detected
> > with CONFIG_DEBUG_LIST.
> >
> > Specifically list operations have been a target for widening flaws to
> > gain
> > "write anywhere" primitives for attackers, so this also consolidates
> > the
> > debug checking to avoid code and check duplication (e.g. RCU list
> > debug
> > was missing a check that got added to regular list debug). It also
> > stops
> > manipulations when corruption is detected, since worsening the
> > corruption
> > makes no sense. (Really, everyone should build with CONFIG_DEBUG_LIST
> > since the checks are so inexpensive.)
> >
> > This is mostly a refactoring of similar code from PaX and Grsecurity,
> > along with MSM kernel changes by Syed Rameez Mustafa.
> >
> > Along with the patches is a new lkdtm test to validate that setting
> > CONFIG_DEBUG_LIST actually does what is desired.
>
> Series looks good to me, too.

Reviewed-by? Acked-by? Ephemeral accolades? ;-)

Thanx, Paul