Hi Kees, Larry,
On 7/20/23 17:15, Kees Cook wrote:
> The declaration of struct shfl_string used trailing fake flexible arrays
> for the string member. This was tripping FORTIFY_SOURCE since commit
> df8fc4e934c1 ("kbuild: Enable -fstrict-flex-arrays=3"). Replace the
> utf8 and utf16 members with actual flexible arrays, drop the unused ucs2
> member, and retriain a 2 byte padding to keep the structure size the same.
>
> Reported-by: Larry Finger <Larry.Finger@xxxxxxxxxxxx>
> Closes: https://lore.kernel.org/lkml/ab3a70e9-60ed-0f13-e3d4-8866eaccc8c1@xxxxxxxxxxxx/
> Tested-by: Larry Finger <Larry.Finger@xxxxxxxxxxxx>
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Kees, Larry thank you for fixing this while I was on vacation.
The patch looks good to me:
Reviewed-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Kees, I'm the vboxsf maintainer and it would be easiest for
me if you can include this in a future 6.5 fixes pull-request
to Linus if that is possible ?
Regards,
Hans
> ---
> fs/vboxsf/shfl_hostintf.h | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/fs/vboxsf/shfl_hostintf.h b/fs/vboxsf/shfl_hostintf.h
> index aca829062c12..069a019c9247 100644
> --- a/fs/vboxsf/shfl_hostintf.h
> +++ b/fs/vboxsf/shfl_hostintf.h
> @@ -68,9 +68,9 @@ struct shfl_string {
>
> /** UTF-8 or UTF-16 string. Nul terminated. */
> union {
> - u8 utf8[2];
> - u16 utf16[1];
> - u16 ucs2[1]; /* misnomer, use utf16. */
> + u8 legacy_padding[2];
> + DECLARE_FLEX_ARRAY(u8, utf8);
> + DECLARE_FLEX_ARRAY(u16, utf16);
> } string;
> };
> VMMDEV_ASSERT_SIZE(shfl_string, 6);
