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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 C6005C4CED1 for ; Sun, 29 Sep 2019 17:41:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9777C21D7D for ; Sun, 29 Sep 2019 17:41:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569778880; bh=k/CKsmCS30QHIytIpsZwjwBWQ5cbvop2pcjUtBpbhDo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=J1jzZvcuAdDDhSY29EQZpGXSPZ0JZ/xZIGAor5S7BNK2MXMlGtt3Z2rVAQ2OM+SNi LcrhYRxbZbcbMtpgUfDH6LTNrD1hFXVdlxnQ+9X8TC8pVBj4l/9NC4FKMwdDuREPlf 3HmS2mssT12wXdu/rB80u+XyHDtY+0abd888y3ac= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729142AbfI2RlP (ORCPT ); Sun, 29 Sep 2019 13:41:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:45070 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730144AbfI2Rdn (ORCPT ); Sun, 29 Sep 2019 13:33:43 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A05D521D7F; Sun, 29 Sep 2019 17:33:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569778422; bh=k/CKsmCS30QHIytIpsZwjwBWQ5cbvop2pcjUtBpbhDo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MoLK1y4+y0R0UF/WrD+DGTZmOYljMosgI7noBBYckNdhdZEygzxSIK1vdA4MQFeiS MlnxtUIN/IbQ4TorC69Ptv08VfdW2b9I4Mw6hYvxElFvhaJmq2EgUHikvhYM1znkpS ZCNA02P4VYvfcn3NQ7EmbUuv9V+HHGzQDVtXI8Zw= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jia-Ju Bai , Casey Schaufler , Sasha Levin , linux-security-module@vger.kernel.org Subject: [PATCH AUTOSEL 5.2 28/42] security: smack: Fix possible null-pointer dereferences in smack_socket_sock_rcv_skb() Date: Sun, 29 Sep 2019 13:32:27 -0400 Message-Id: <20190929173244.8918-28-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190929173244.8918-1-sashal@kernel.org> References: <20190929173244.8918-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: 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 4c5e5a438f8bd..5c9fc8ba6e572 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -3925,6 +3925,8 @@ static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) 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 = family; -- 2.20.1