From patchwork Mon Mar 26 11:27:12 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Colin Ian King X-Patchwork-Id: 890903 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=canonical.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 408sLs3XNgz9s1l for ; Mon, 26 Mar 2018 22:27:33 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751980AbeCZL1V (ORCPT ); Mon, 26 Mar 2018 07:27:21 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:48134 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751024AbeCZL1U (ORCPT ); Mon, 26 Mar 2018 07:27:20 -0400 Received: from 1.general.cking.uk.vpn ([10.172.193.212] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.76) (envelope-from ) id 1f0QHR-0000ok-5k; Mon, 26 Mar 2018 11:27:13 +0000 From: Colin King To: "David S . Miller" , Dan Carpenter , Samuel Mendoza-Jonas , netdev@vger.kernel.org Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] net/ncsi: check for null return from call to nla_nest_start Date: Mon, 26 Mar 2018 12:27:12 +0100 Message-Id: <20180326112712.31165-1-colin.king@canonical.com> X-Mailer: git-send-email 2.15.1 MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Colin Ian King The call to nla_nest_start calls nla_put which can lead to a NULL return so it's possible for attr to become NULL and we can potentially get a NULL pointer dereference on attr. Fix this by checking for a NULL return. Detected by CoverityScan, CID#1466125 ("Dereference null return") Fixes: 955dc68cb9b2 ("net/ncsi: Add generic netlink family") Signed-off-by: Colin Ian King --- net/ncsi/ncsi-netlink.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/ncsi/ncsi-netlink.c b/net/ncsi/ncsi-netlink.c index 05fcfb4fbe1d..8d7e849d4825 100644 --- a/net/ncsi/ncsi-netlink.c +++ b/net/ncsi/ncsi-netlink.c @@ -190,6 +190,10 @@ static int ncsi_pkg_info_nl(struct sk_buff *msg, struct genl_info *info) package_id = nla_get_u32(info->attrs[NCSI_ATTR_PACKAGE_ID]); attr = nla_nest_start(skb, NCSI_ATTR_PACKAGE_LIST); + if (!attr) { + kfree_skb(skb); + return -EMSGSIZE; + } rc = ncsi_write_package_info(skb, ndp, package_id); if (rc) {