[PATCH 07/11] localte: Fix UB on collate_finish

[Andreas Schwab]

On Mai 07 2025, Adhemerval Zanella wrote:

> diff --git a/locale/programs/ld-collate.c b/locale/programs/ld-collate.c
> index 4fa08bd273..5ed03f4cbf 100644
> --- a/locale/programs/ld-collate.c
> +++ b/locale/programs/ld-collate.c
> @@ -1554,7 +1554,7 @@ collate_finish (struct localedef_t *locale, const struct charmap_t *charmap)
>       The multibyte case is easy.  We simply sort into an array with
>       256 elements.  */
>    struct locale_collate_t *collate = locale->categories[LC_COLLATE].collate;
> -  int mbact[nrules];
> +  int mbact[nrules == 0 ? 1 : nrules];

nrules is guaranteed to be at most sizeof (((struct element_t *)
0)->used_in_level) * 8, so this can use a fixed array.

-- 
Andreas Schwab, SUSE Labs, schwab@suse.de
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