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

On Tue, Aug 17, 2021 at 11:05:19PM -0700, 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@fb.com Cc: Josef Bacik josef@toxicpanda.com Cc: David Sterba dsterba@suse.com Cc: linux-btrfs@vger.kernel.org Signed-off-by: Kees Cook keescook@chromium.org

Acked-by: David Sterba dsterba@suse.com