From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CDBF0C433F5 for ; Mon, 3 Sep 2018 16:00:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 790B520645 for ; Mon, 3 Sep 2018 16:00:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 790B520645 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.cz Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727483AbeICUVe (ORCPT ); Mon, 3 Sep 2018 16:21:34 -0400 Received: from mx2.suse.de ([195.135.220.15]:39952 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725969AbeICUVe (ORCPT ); Mon, 3 Sep 2018 16:21:34 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 1AB74AEA7; Mon, 3 Sep 2018 16:00:47 +0000 (UTC) Date: Mon, 3 Sep 2018 18:00:45 +0200 (CEST) From: Miroslav Benes To: Petr Mladek cc: Jiri Kosina , Josh Poimboeuf , Jason Baron , Joe Lawrence , Jessica Yu , Evgenii Shatokhin , live-patching@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v12 07/12] livepatch: Use lists to manage patches, objects and functions In-Reply-To: <20180828143603.4442-8-pmladek@suse.com> Message-ID: References: <20180828143603.4442-1-pmladek@suse.com> <20180828143603.4442-8-pmladek@suse.com> User-Agent: Alpine 2.21 (LSU 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > -#define klp_for_each_object(patch, obj) \ > +#define klp_for_each_object_static(patch, obj) \ > for (obj = patch->objs; obj->funcs || obj->name; obj++) > > -#define klp_for_each_func(obj, func) \ > +#define klp_for_each_object(patch, obj) \ > + list_for_each_entry(obj, &patch->obj_list, node) > + > +#define klp_for_each_func_static(obj, func) \ > for (func = obj->funcs; \ > func->old_name || func->new_addr || func->old_sympos; \ > func++) > > +#define klp_for_each_func(obj, func) \ > + list_for_each_entry(func, &obj->func_list, node) > + > int klp_enable_patch(struct klp_patch *); > > void arch_klp_init_object_loaded(struct klp_patch *patch, > diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c > index 6a47b36a6c9a..7bc23a106b5b 100644 > --- a/kernel/livepatch/core.c > +++ b/kernel/livepatch/core.c > @@ -50,6 +50,21 @@ LIST_HEAD(klp_patches); > > static struct kobject *klp_root_kobj; > > +static void klp_init_lists(struct klp_patch *patch) > +{ > + struct klp_object *obj; > + struct klp_func *func; > + > + INIT_LIST_HEAD(&patch->obj_list); > + klp_for_each_object_static(patch, obj) { > + list_add(&obj->node, &patch->obj_list); > + > + INIT_LIST_HEAD(&obj->func_list); > + klp_for_each_func_static(obj, func) > + list_add(&func->node, &obj->func_list); > + } > +} > + > static bool klp_is_module(struct klp_object *obj) > { > return obj->name; > @@ -664,6 +679,7 @@ static int klp_init_patch(struct klp_patch *patch) > patch->module_put = false; > INIT_LIST_HEAD(&patch->list); > init_completion(&patch->finish); > + klp_init_lists(patch); This could explode easily if patch->objs is NULL. The check is just below. > if (!patch->objs) > return -EINVAL; Here. klp_init_lists() calls klp_for_each_object_static() which accesses obj->name without a check for obj. One could argue that it is a responsibility of the user not to do such a silly thing, but since the check is already there, could you move klp_init_lists() call after the check? Regards, Miroslav