From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ursula Braun Subject: [PATCH net 1/4] net/smc: take sock lock in smc_ioctl() Date: Mon, 16 Jul 2018 12:01:01 +0200 Message-ID: <20180716100101.79272-1-ubraun@linux.ibm.com> Cc: netdev@vger.kernel.org, linux-s390@vger.kernel.org, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, raspl@linux.ibm.com, linux-kernel@vger.kernel.org, eric.dumazet@gmail.com, lifeasageek@gmail.com To: davem@davemloft.net Return-path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:33356 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727596AbeGPK14 (ORCPT ); Mon, 16 Jul 2018 06:27:56 -0400 Received: from pps.filterd (m0098419.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w6G9xT7Z117864 for ; Mon, 16 Jul 2018 06:01:17 -0400 Received: from e06smtp01.uk.ibm.com (e06smtp01.uk.ibm.com [195.75.94.97]) by mx0b-001b2d01.pphosted.com with ESMTP id 2k8rd4a42e-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 16 Jul 2018 06:01:17 -0400 Received: from localhost by e06smtp01.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 16 Jul 2018 11:01:15 +0100 Sender: netdev-owner@vger.kernel.org List-ID: From: Ursula Braun SMC ioctl processing requires the sock lock to work properly in all thinkable scenarios. Problem has been found with RaceFuzzer and fixes: KASAN: null-ptr-deref Read in smc_ioctl Reported-by: Byoungyoung Lee Reported-by: syzbot+35b2c5aa76fd398b9fd4@syzkaller.appspotmail.com Signed-off-by: Ursula Braun --- net/smc/af_smc.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index 5334157f5065..a4381b38a521 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -1524,6 +1524,7 @@ static int smc_ioctl(struct socket *sock, unsigned int cmd, return -EBADF; return smc->clcsock->ops->ioctl(smc->clcsock, cmd, arg); } + lock_sock(&smc->sk); switch (cmd) { case SIOCINQ: /* same as FIONREAD */ if (smc->sk.sk_state == SMC_LISTEN) @@ -1573,8 +1574,10 @@ static int smc_ioctl(struct socket *sock, unsigned int cmd, } break; default: + release_sock(&smc->sk); return -ENOIOCTLCMD; } + release_sock(&smc->sk); return put_user(answ, (int __user *)arg); } -- 2.16.4