[PATCH] kasan:fix access invalid shadow address when input is illegal

[Andrey Konovalov]

On Fri, Sep 15, 2023 at 4:46 AM 'Haibo Li' via kasan-dev
<kasan-dev at googlegroups.com> wrote:
>
> The patch checks each shadow address,so it introduces extra overhead.

Ack. Could still be fine, depends on the overhead.

But if the message printed by kasan_non_canonical_hook is good enough
for your use case, I would rather stick to that.

> Now kasan_non_canonical_hook only works for CONFIG_KASAN_INLINE.
>
> And CONFIG_KASAN_OUTLINE is set in my case.
>
> Is it possible to make kasan_non_canonical_hook works for both
> INLINE and OUTLINE by simply remove the "#ifdef CONFIG_KASAN_INLINE"?

Yes, it should just work if you remove the ifdefs in mm/kasan/report.c
and in include/linux/kasan.h.

Jann, do you have any objections to enabling kasan_non_canonical_hook
for the outline mode too?

> Since kasan_non_canonical_hook is only used after kernel fault,it
> is better if there is no limit.