Ben Hutchings <b...@decadent.org.uk> writes:
> Signing a module should only make it trusted by the specific kernel it
> was built for, not anything else. Loading a signed module meant for a
> kernel with a different ABI could have interesting effects.
> Therefore, treat all signatures as invalid when a module is
> force-loaded.
>
> Signed-off-by: Ben Hutchings <b...@decadent.org.uk>
> Cc: sta...@vger.kernel.org
> ---
> kernel/module.c | 13 +++++++++----
> 1 file changed, 9 insertions(+), 4 deletions(-)
>
> diff --git a/kernel/module.c b/kernel/module.c
> index 66426f743c29..649b1827ed15 100644
> --- a/kernel/module.c
> +++ b/kernel/module.c
> @@ -2599,13 +2599,18 @@ static inline void kmemleak_load_module(const struct
> module *mod,
> #endif
>
> #ifdef CONFIG_MODULE_SIG
> -static int module_sig_check(struct load_info *info)
> +static int module_sig_check(struct load_info *info, int flags)
> {
> int err = -ENOKEY;
> const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
> const void *mod = info->hdr;
>
> - if (info->len > markerlen &&
> + /*
> + * Require flags == 0, as a module with version information
> + * removed is no longer the module that was signed
> + */
> + if (flags == 0 &&
This check is a bit lazy. We could have other flags in future,
so this should really be !(flags &
(MODULE_INIT_IGNORE_MODVERSIONS|MODULE_INIT_IGNORE_VERMAGIC) right?
Cheers,
Rusty.
