Re: [PATCH v3 1/3] slab: make check_object() more consistent

[Kees Cook <kees@kernel.org>]

On Tue, Jun 11, 2024 at 03:52:49PM -0700, Christoph Lameter (Ampere) wrote:
> On Mon, 10 Jun 2024, Vlastimil Babka wrote:
> 
> > Even if some security people enable parts of slub debugging for security
> > people it is my impression they would rather panic/reboot or have memory
> > leaked than trying to salvage the slab page? (CC Kees)
> 
> In the past these resilience features have been used to allow the continued
> operation of a broken kernel.
> 
> So first the Kernel crashed with some obscure oops in the allocator due to
> metadata corruption.
> 
> One can then put a slub_debug option on the kernel command line which will
> result in detailed error reports on what caused the corruption. It will also
> activate resilience measures that will often allow the continued operation
> until a fix becomes available.

Sure, as long as it's up to the deployment. I just don't want padding
errors unilaterally ignored. If it's useful, there's the
CHECK_DATA_CORRUPTION() macro. That'll let a deployment escalate the
issue from WARN to BUG, etc.

-- 
Kees Cook