livepatch: fix format string in kobject_init_and_add()

kobject_init_and_add() takes expects format string for a name, so we
better provide it in order to avoid infoleaks if modules craft their
mod->name in a special way.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Reported-by: Kees Cook <keescook@chromium.org>
Acked-by: Seth Jennings <sjenning@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index ff7f47d..69bf3aa 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -731,7 +731,7 @@
 	func->state = KLP_DISABLED;
 
 	return kobject_init_and_add(&func->kobj, &klp_ktype_func,
-				    obj->kobj, func->old_name);
+				    obj->kobj, "%s", func->old_name);
 }
 
 /* parts of the initialization that is done only when the object is loaded */
@@ -807,7 +807,7 @@
 	patch->state = KLP_DISABLED;
 
 	ret = kobject_init_and_add(&patch->kobj, &klp_ktype_patch,
-				   klp_root_kobj, patch->mod->name);
+				   klp_root_kobj, "%s", patch->mod->name);
 	if (ret)
 		goto unlock;