Re: [PATCH] exec: clarify reasoning for euid/egid reset

[David Howells]

Kees Cook <keescook@xxxxxxxxxxxx> wrote:

> -	/* clear any previous set[ug]id data from a previous binary */
> +	/*
> +	 * Since this can be called multiple times (via prepare_binprm),
> +	 * we must clear any previous work done when setting set[ug]id
> +	 * bits from any earlier bprm->file uses (for example when run
> +	 * first for a script then for its interpreter).
> +	 */
>  	bprm->cred->euid = current_euid();
>  	bprm->cred->egid = current_egid();

I would further add that this is where we deal with setuid scripts.

David