On 9/23/23 1:49 AM, Kees Cook wrote:
> Prepare for the coming implementation by GCC and Clang of the __counted_by
> attribute. Flexible array members annotated with __counted_by can have
> their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
> (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
> functions).
>
> As found with Coccinelle[1], add __counted_by for struct ocfs2_replay_map.
>
> [1]
> https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Mark Fasheh <m...@fasheh.com>
> Cc: Joel Becker <jl...@evilplan.org>
> Cc: Joseph Qi <joseph...@linux.alibaba.com>
> Cc: Nathan Chancellor <nat...@kernel.org>
> Cc: Nick Desaulniers <ndesaulni...@google.com>
> Cc: Tom Rix <t...@redhat.com>
> Cc: ocfs2-de...@lists.linux.dev
> Cc: l...@lists.linux.dev
> Signed-off-by: Kees Cook <keesc...@chromium.org>
Reviewed-by: Joseph Qi <joseph...@linux.alibaba.com>
> ---
> fs/ocfs2/journal.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c
> index ce215565d061..604fea3a26ff 100644
> --- a/fs/ocfs2/journal.c
> +++ b/fs/ocfs2/journal.c
> @@ -90,7 +90,7 @@ enum ocfs2_replay_state {
> struct ocfs2_replay_map {
> unsigned int rm_slots;
> enum ocfs2_replay_state rm_state;
> - unsigned char rm_replay_slots[];
> + unsigned char rm_replay_slots[] __counted_by(rm_slots);
> };
>
> static void ocfs2_replay_map_set_state(struct ocfs2_super *osb, int state)
