Re: [PATCH v2 49/63] btrfs: Use memset_startat() to clear end of struct

From: Nikolay Borisov
Date: Wed Aug 18 2021 - 02:36:03 EST




On 18.08.21 г. 9:05, Kees Cook wrote:
> In preparation for FORTIFY_SOURCE performing compile-time and run-time
> field bounds checking for memset(), avoid intentionally writing across
> neighboring fields.
>
> Use memset_startat() so memset() doesn't get confused about writing
> beyond the destination member that is intended to be the starting point
> of zeroing through the end of the struct.
>
> Cc: Chris Mason <clm@xxxxxx>
> Cc: Josef Bacik <josef@xxxxxxxxxxxxxx>
> Cc: David Sterba <dsterba@xxxxxxxx>
> Cc: linux-btrfs@xxxxxxxxxxxxxxx
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>

Reviewed-by: Nikolay Borisov <nborisov@xxxxxxxx>