Re: [PATCH][next] udf: Fix undefined behavior bug in struct udf_fileident_iter

From: Jan Kara
Date: Tue Oct 03 2023 - 05:26:49 EST


On Mon 02-10-23 18:14:26, Gustavo A. R. Silva wrote:
> `struct fileIdentDesc` is a flexible structure, which means that it
> contains a flexible-array member at the bottom. This could potentially
> lead to an overwrite of the objects following `fi` in `struct
> udf_fileident_iter` at run-time.
>
> Fix this by placing the declaration of object `fi` at the end of
> `struct udf_fileident_iter`.
>
> -Wflex-array-member-not-at-end is coming in GCC-14, and we are getting
> ready to enable it globally.
>
> Fixes: d16076d9b684 ("udf: New directory iteration code")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>

Thanks for the patch! This is in fact harmless since we never use the
impUse field. But I agree it is confusing so I'll merge attached fix
instead.

Honza
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR