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

From: Rik van Riel
Date: Thu Aug 18 2016 - 20:53:21 EST


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.