Re: [PATCH] module: Add log information for loading module failures

Luis Chamberlain
2024-06-18T18:54:59Z

On Fri, Jun 14, 2024 at 09:25:19AM +0000, Yusong Gao wrote:
> Add log information in kernel-space when loading module failures.
> Try to load the unsigned module and the module with bad signature
> when set 1 to /sys/module/module/parameters/sig_enforce.
>
> Unsigned module case:
> (linux) insmod unsigned.ko
> [ 18.714661] Loading of unsigned module is rejected
> insmod: can't insert 'unsigned.ko': Key was rejected by service
> (linux)
>
> Bad signature module case:
> (linux) insmod bad_signature.ko
> insmod: can't insert 'bad_signature.ko': Key was rejected by service
> (linux)
>
> There have different logging behavior the bad signature case only log
> in user-space, add log info for fatal errors in module_sig_check().
>
> Signed-off-by: Yusong Gao <a869920004@gmail.com>
> ---
> kernel/module/signing.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/kernel/module/signing.c b/kernel/module/signing.c
> index a2ff4242e623..6a6493c8f7e4 100644
> --- a/kernel/module/signing.c
> +++ b/kernel/module/signing.c
> @@ -113,6 +113,7 @@ int module_sig_check(struct load_info *info, int flags)
> * unparseable signatures, and signature check failures --
> * even if signatures aren't required.
> */
> + pr_notice("Loading module failed (errno=%d)\n", -err);
> return err;

I welcome pr_debug() messages but if we were to add a regular print for every
single type of failure we'd clutter the code, we don't want that.

Luis