2023-09-15 21:03:46

by Gustavo A. R. Silva

[permalink] [raw]
Subject: Re: [PATCH] udf: Annotate struct udf_bitmap with __counted_by



On 9/15/23 14:14, 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 udf_bitmap.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Jan Kara <[email protected]>
> Signed-off-by: Kees Cook <[email protected]>

Reviewed-by: Gustavo A. R. Silva <[email protected]>

Thanks
--
Gustavo

> ---
> fs/udf/udf_sb.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/udf/udf_sb.h b/fs/udf/udf_sb.h
> index 9af6ff7f9747..f9a60bc1abcf 100644
> --- a/fs/udf/udf_sb.h
> +++ b/fs/udf/udf_sb.h
> @@ -86,7 +86,7 @@ struct udf_virtual_data {
> struct udf_bitmap {
> __u32 s_extPosition;
> int s_nr_groups;
> - struct buffer_head *s_block_bitmap[];
> + struct buffer_head *s_block_bitmap[] __counted_by(s_nr_groups);
> };
>
> struct udf_part_map {


2023-09-18 09:23:45

by Jan Kara

[permalink] [raw]
Subject: Re: [PATCH] udf: Annotate struct udf_bitmap with __counted_by

On Fri 15-09-23 14:50:14, Gustavo A. R. Silva wrote:
>
>
> On 9/15/23 14:14, 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 udf_bitmap.
> >
> > [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
> >
> > Cc: Jan Kara <[email protected]>
> > Signed-off-by: Kees Cook <[email protected]>
>
> Reviewed-by: Gustavo A. R. Silva <[email protected]>

Thanks. I've queued the patch to my tree.

Honza
--
Jan Kara <[email protected]>
SUSE Labs, CR