From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756808AbcDGQGb (ORCPT ); Thu, 7 Apr 2016 12:06:31 -0400 Received: from mx2.suse.de ([195.135.220.15]:40387 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756546AbcDGQG1 (ORCPT ); Thu, 7 Apr 2016 12:06:27 -0400 Date: Thu, 7 Apr 2016 18:06:25 +0200 (CEST) From: Jiri Kosina X-X-Sender: jkosina@pobox.suse.cz To: Dan Carpenter cc: jeyu@redhat.com, Josh Poimboeuf , Miroslav Benes , Petr Mladek , live-patching@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] livepatch: robustify klp_register_patch() API error checking In-Reply-To: <20160404203426.GA8200@mwanda> Message-ID: References: <20160404203426.GA8200@mwanda> User-Agent: Alpine 2.00 (LNX 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jiri Kosina Commit 425595a7fc20 ("livepatch: reuse module loader code to write relocations") adds a possibility of dereferncing pointers supplied by the consumer of the livepatch API before sanity (NULL) checking them (patch and patch->mod). Spotted by smatch tool. Reported-by: Dan Carpenter Signed-off-by: Jiri Kosina --- kernel/livepatch/core.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c index eb5db6e..28c37fa 100644 --- a/kernel/livepatch/core.c +++ b/kernel/livepatch/core.c @@ -876,6 +876,9 @@ int klp_register_patch(struct klp_patch *patch) { int ret; + if (!patch || !patch->mod) + return -EINVAL; + if (!is_livepatch_module(patch->mod)) { pr_err("module %s is not marked as a livepatch module", patch->mod->name); @@ -885,9 +888,6 @@ int klp_register_patch(struct klp_patch *patch) if (!klp_initialized()) return -ENODEV; - if (!patch || !patch->mod) - return -EINVAL; - /* * A reference is taken on the patch module to prevent it from being * unloaded. Right now, we don't allow patch modules to unload since -- Jiri Kosina SUSE Labs