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

[Will Deacon]

On Tue, Dec 07, 2021 at 06:32:24PM +0000, Mark Rutland 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]

Cheers, that should help with debugging!

Acked-by: Will Deacon <will at kernel.org>

Will