From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758735AbYELNio (ORCPT ); Mon, 12 May 2008 09:38:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755276AbYELNid (ORCPT ); Mon, 12 May 2008 09:38:33 -0400 Received: from mgw1.diku.dk ([130.225.96.91]:44154 "EHLO mgw1.diku.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751768AbYELNib (ORCPT ); Mon, 12 May 2008 09:38:31 -0400 Date: Mon, 12 May 2008 15:38:26 +0200 (CEST) From: Julia Lawall To: pantelis.antoniou@gmail.com, vbordug@ru.mvista.com, linuxppc-dev@ozlabs.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: [PATCH 4/6] drivers/net/fs_enet: remove null pointer dereference Message-ID: 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: Julia Lawall The following code appears in the function fs_init_instance in the file drivers/net/fs_enet/fs_enet-main.c. if (fep->ops == NULL) { printk(KERN_ERR DRV_MODULE_NAME ": %s No matching ops found (%d).\n", ndev->name, fpi->fs_no); err = -EINVAL; goto err; } This code implies that at the point of err, fep->ops can be NULL, so an extra test is needed before dereferencing this value. This problem was found using the following semantic match (http://www.emn.fr/x-info/coccinelle/) // @@ expression E, E1; identifier f; statement S1,S2,S3; @@ * if (E == NULL) { ... when != if (E == NULL) S1 else S2 when != E = E1 * E->f ... when any return ...; } else S3 // Signed-off-by: Julia Lawall --- diff -u -p a/drivers/net/fs_enet/fs_enet-main.c b/drivers/net/fs_enet/fs_enet-main.c --- a/drivers/net/fs_enet/fs_enet-main.c 2008-04-27 11:41:11.000000000 +0200 +++ b/drivers/net/fs_enet/fs_enet-main.c 2008-05-12 09:41:52.000000000 +0200 @@ -1093,7 +1093,7 @@ err: if (registered) unregister_netdev(ndev); - if (fep != NULL) { + if (fep && fep->ops) { (*fep->ops->free_bd)(ndev); (*fep->ops->cleanup_data)(ndev); }