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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 39C4BECE597 for ; Sun, 6 Oct 2019 17:20:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 071602077B for ; Sun, 6 Oct 2019 17:20:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570382416; bh=6WSWZ02RsQ66w1zpCEaXKB2vQXYZViz7eKNvbYXWB24=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=rvAjrWuP2e6MYUGKJwd0iJ3TS/EUsbCvyrGZm7aCFjjtkBrw2alrZH68TU6Fb8OVP 2gMo1mn4Q6YjdDQ2WSLIzsLf0o8EOcHSvGGMTmhEKV1BHSeKdqL285XCPr3/tZfOwt 5WFwev1Amkd+4U0GMX5lKD6YutxaxpdhWc4fI1Ko= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726970AbfJFRTv (ORCPT ); Sun, 6 Oct 2019 13:19:51 -0400 Received: from mail.kernel.org ([198.145.29.99]:44792 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726949AbfJFRTu (ORCPT ); Sun, 6 Oct 2019 13:19:50 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7D5CB20862; Sun, 6 Oct 2019 17:19:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570382390; bh=6WSWZ02RsQ66w1zpCEaXKB2vQXYZViz7eKNvbYXWB24=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tojbrY3GX+MuheesopMFxDMFm/nJw6k/aPby5FVhMYisN8w1gVo1hfnN53R/28Rrg dvXlif5mg2IptWqomvwksFaVMgyf0AeIWX+HAmNG+tcDOeLm2xYXNuZLUsVQcGZIK5 LYbeZAgjLfdcsx4qFPMmtV3jF43NVW4g0/LF9eQI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jia-Ju Bai , Casey Schaufler , Sasha Levin Subject: [PATCH 4.4 18/36] security: smack: Fix possible null-pointer dereferences in smack_socket_sock_rcv_skb() Date: Sun, 6 Oct 2019 19:19:00 +0200 Message-Id: <20191006171052.639006834@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191006171038.266461022@linuxfoundation.org> References: <20191006171038.266461022@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Jia-Ju Bai [ Upstream commit 3f4287e7d98a2954f20bf96c567fdffcd2b63eb9 ] In smack_socket_sock_rcv_skb(), there is an if statement on line 3920 to check whether skb is NULL: if (skb && skb->secmark != 0) This check indicates skb can be NULL in some cases. But on lines 3931 and 3932, skb is used: ad.a.u.net->netif = skb->skb_iif; ipv6_skb_to_auditdata(skb, &ad.a, NULL); Thus, possible null-pointer dereferences may occur when skb is NULL. To fix these possible bugs, an if statement is added to check skb. These bugs are found by a static analysis tool STCheck written by us. Signed-off-by: Jia-Ju Bai Signed-off-by: Casey Schaufler Signed-off-by: Sasha Levin --- security/smack/smack_lsm.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 9db7c80a74aa5..b76075dbd6fc8 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -3986,6 +3986,8 @@ access_check: skp = smack_ipv6host_label(&sadd); if (skp == NULL) skp = smack_net_ambient; + if (skb == NULL) + break; #ifdef CONFIG_AUDIT smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); ad.a.u.net->family = sk->sk_family; -- 2.20.1