[PATCH v2 0/2] arm64: kasan: log potential KASAN shadow aliases

[Andrey Konovalov]

On Tue, Dec 7, 2021 at 7:32 PM Mark Rutland <mark.rutland at arm.com> wrote:
>
> When using KASAN_GENERIC or KASAN_SW_TAGS, many representable pointer
> values (e.g. NULL) don't have a legitimate shadow address. If KASAN
> instrumentation attempts to access the shadow for such pointers, it will
> fault on an unusual-looking address, e.g.
>
> | Unable to handle kernel paging request at virtual address dfff800000000001
>
> To make this easier to debug, this series makes the arm64 fault handling
> code log the corresponding memory range for potential shadow acceses,
> e.g.
>
> | Unable to handle kernel paging request at virtual address dfff800000000017
> | KASAN: null-ptr-deref in range [0x00000000000000b8-0x00000000000000bf]
>
> Since v1 [1]:
> * Use kasan_non_canonical_hook()
> * Drop move of kasan_shadow_to_mem()
> * Update commit messages
>
> [1] https://lore.kernel.org/r/20211202112731.3346975-1-mark.rutland@arm.com
>
> Thanks,
> Mark.
>
> Mark Rutland (2):
>   arm64: mm: use die_kernel_fault() in do_mem_abort()
>   arm64: mm: log potential KASAN shadow alias
>
>  arch/arm64/mm/fault.c | 9 ++++-----
>  1 file changed, 4 insertions(+), 5 deletions(-)
>
> --
> 2.30.2
>

Tested-by: Andrey Konovalov <andreyknvl at gmail.com>

Thanks, Mark!