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

Steven Rostedt
2016-08-18T13:47:06Z

On Wed, 17 Aug 2016 14:42:07 -0700
Kees Cook <keescook@chromium.org> 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.
>

The series looks fine by me.

Acked-by: Steven Rostedt <rostedt@goodmis.org>

-- Steve

> Thanks,
>
> -Kees
>
> v3:
> - fix MSM attribution, sboyd
> - use pr_err, joe
>
> v2:
> - consolidate printk/WARN/BUG/return logic into a CONFIG-specific macro
> - drop non-list BUGs, labbott