On 3/19/23 22:27, Luis Chamberlain wrote:
> Move early sanity checkers for the module into a helper.
> This let's us make it clear when we are working with the
> local copy of the module prior to allocation.
>
> This produces no functional changes, it just makes subsequent
> changes easier to read.
>
> Signed-off-by: Luis Chamberlain <mcgrof@xxxxxxxxxx>
> ---
> kernel/module/main.c | 43 ++++++++++++++++++++++++++-----------------
> 1 file changed, 26 insertions(+), 17 deletions(-)
>
> diff --git a/kernel/module/main.c b/kernel/module/main.c
> index 427284ab31f1..933cef72ae13 100644
> --- a/kernel/module/main.c
> +++ b/kernel/module/main.c
> @@ -2668,6 +2668,31 @@ static int unknown_module_param_cb(char *param, char *val, const char *modname,
> return 0;
> }
>
> +/* Module within temporary copy, this doesn't do any allocation */
> +static int early_mod_check(struct load_info *info, int flags)
> +{
> + int err;
> +
> + /*
> + * Now that we know we have the correct module name, check
> + * if it's blacklisted.
> + */
> + if (blacklisted(info->name)) {
> + pr_err("Module %s is blacklisted\n", info->name);
> + return -EPERM;
> + }
> +
> + err = rewrite_section_headers(info, flags);
> + if (err)
> + return err;
> +
> + /* Check module struct version now, before we try to use module. */
> + if (!check_modstruct_version(info, info->mod))
> + return ENOEXEC;
The error value when check_modstruct_version() fails is changed in this patch
from -ENOEXEC to ENOEXEC and updated back again in the next patch. It would be
good to avoid introducing this temporary problem and keep the value throughout
as -ENOEXEC.
> +
> + return 0;
> +}
> +
> /*
> * Allocate and load the module: note that size of section 0 is always
> * zero, and we rely on this for optional sections.
> @@ -2711,26 +2736,10 @@ static int load_module(struct load_info *info, const char __user *uargs,
> if (err)
> goto free_copy;
>
> - /*
> - * Now that we know we have the correct module name, check
> - * if it's blacklisted.
> - */
> - if (blacklisted(info->name)) {
> - err = -EPERM;
> - pr_err("Module %s is blacklisted\n", info->name);
> - goto free_copy;
> - }
> -
> - err = rewrite_section_headers(info, flags);
> + err = early_mod_check(info, flags);
> if (err)
> goto free_copy;
>
> - /* Check module struct version now, before we try to use module. */
> - if (!check_modstruct_version(info, info->mod)) {
> - err = -ENOEXEC;
Original value here.
> - goto free_copy;
> - }
> -
> /* Figure out module layout, and allocate all the memory. */
> mod = layout_and_allocate(info, flags);
> if (IS_ERR(mod)) {
Thanks,
Petr
