Re: [PATCH 6/7] exec: Factor bprm_stack_limits out of prepare_arg_pages

From: Kees Cook
Date: Tue Jul 14 2020 - 17:41:09 EST


On Tue, Jul 14, 2020 at 08:31:03AM -0500, Eric W. Biederman wrote:
>
> In preparation for implementiong kernel_execve (which will take kernel
> pointers not userspace pointers) factor out bprm_stack_limits out of
> prepare_arg_pages. This separates the counting which depends upon the
> getting data from userspace from the calculations of the stack limits
> which is usable in kernel_execve.
>
> The remove prepare_args_pages and compute bprm->argc and bprm->envc
> directly in do_execveat_common, before bprm_stack_limits is called.
>
> Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>

Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>

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Kees Cook