From patchwork Wed Feb 28 11:44:09 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ursula Braun X-Patchwork-Id: 879074 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@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=none (p=none dis=none) header.from=linux.vnet.ibm.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3zrtyb00Qkz9s0v for ; Wed, 28 Feb 2018 22:44:38 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752415AbeB1Loh (ORCPT ); Wed, 28 Feb 2018 06:44:37 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:49362 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752360AbeB1Lo2 (ORCPT ); Wed, 28 Feb 2018 06:44:28 -0500 Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w1SBh1B5054437 for ; Wed, 28 Feb 2018 06:44:28 -0500 Received: from e06smtp11.uk.ibm.com (e06smtp11.uk.ibm.com [195.75.94.107]) by mx0b-001b2d01.pphosted.com with ESMTP id 2gdtb8bhns-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 28 Feb 2018 06:44:28 -0500 Received: from localhost by e06smtp11.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Wed, 28 Feb 2018 11:44:23 -0000 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w1SBiMT357540790; Wed, 28 Feb 2018 11:44:22 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 7C3795204C; Wed, 28 Feb 2018 10:36:08 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.152.85.9]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTPS id 2AAA952045; Wed, 28 Feb 2018 10:36:08 +0000 (GMT) From: Ursula Braun To: davem@davemloft.net Cc: netdev@vger.kernel.org, linux-s390@vger.kernel.org, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, raspl@linux.vnet.ibm.com, ubraun@linux.vnet.ibm.com Subject: [PATCH net 3/3] net/smc: fix NULL pointer dereference on sock_create_kern() error path Date: Wed, 28 Feb 2018 12:44:09 +0100 X-Mailer: git-send-email 2.13.5 In-Reply-To: <20180228114409.33645-1-ubraun@linux.vnet.ibm.com> References: <20180228114409.33645-1-ubraun@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 18022811-0040-0000-0000-00000438C907 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18022811-0041-0000-0000-000020DAFA1C Message-Id: <20180228114409.33645-4-ubraun@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2018-02-28_07:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1802280141 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Davide Caratti when sock_create_kern(..., a) returns an error, 'a' might not be a valid pointer, so it shouldn't be dereferenced to read a->sk->sk_sndbuf and and a->sk->sk_rcvbuf; not doing that caused the following crash: general protection fault: 0000 [#1] SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 0 PID: 4254 Comm: syzkaller919713 Not tainted 4.16.0-rc1+ #18 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:smc_create+0x14e/0x300 net/smc/af_smc.c:1410 RSP: 0018:ffff8801b06afbc8 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffff8801b63457c0 RCX: ffffffff85a3e746 RDX: 0000000000000004 RSI: 00000000ffffffff RDI: 0000000000000020 RBP: ffff8801b06afbf0 R08: 00000000000007c0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffff8801b6345c08 R14: 00000000ffffffe9 R15: ffffffff8695ced0 FS: 0000000001afb880(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000040 CR3: 00000001b0721004 CR4: 00000000001606f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __sock_create+0x4d4/0x850 net/socket.c:1285 sock_create net/socket.c:1325 [inline] SYSC_socketpair net/socket.c:1409 [inline] SyS_socketpair+0x1c0/0x6f0 net/socket.c:1366 do_syscall_64+0x282/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x26/0x9b RIP: 0033:0x4404b9 RSP: 002b:00007fff44ab6908 EFLAGS: 00000246 ORIG_RAX: 0000000000000035 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004404b9 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 000000000000002b RBP: 00007fff44ab6910 R08: 0000000000000002 R09: 00007fff44003031 R10: 0000000020000040 R11: 0000000000000246 R12: ffffffffffffffff R13: 0000000000000006 R14: 0000000000000000 R15: 0000000000000000 Code: 48 c1 ea 03 80 3c 02 00 0f 85 b3 01 00 00 4c 8b a3 48 04 00 00 48 b8 00 00 00 00 00 fc ff df 49 8d 7c 24 20 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 82 01 00 00 4d 8b 7c 24 20 48 b8 00 00 00 00 RIP: smc_create+0x14e/0x300 net/smc/af_smc.c:1410 RSP: ffff8801b06afbc8 Fixes: cd6851f30386 smc: remote memory buffers (RMBs) Reported-and-tested-by: syzbot+aa0227369be2dcc26ebe@syzkaller.appspotmail.com Signed-off-by: Davide Caratti Signed-off-by: Ursula Braun --- net/smc/af_smc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index da1a5cdefd13..8cc97834d4f6 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -1406,8 +1406,10 @@ static int smc_create(struct net *net, struct socket *sock, int protocol, smc->use_fallback = false; /* assume rdma capability first */ rc = sock_create_kern(net, PF_INET, SOCK_STREAM, IPPROTO_TCP, &smc->clcsock); - if (rc) + if (rc) { sk_common_release(sk); + goto out; + } smc->sk.sk_sndbuf = max(smc->clcsock->sk->sk_sndbuf, SMC_BUF_MIN_SIZE); smc->sk.sk_rcvbuf = max(smc->clcsock->sk->sk_rcvbuf, SMC_BUF_MIN_SIZE);