From mboxrd@z Thu Jan 1 00:00:00 1970 From: Prashant Bhole Subject: [PATCH net-next] rtnetlink: Fix null-ptr-deref in rtnl_newlink Date: Fri, 1 Jun 2018 17:16:58 +0900 Message-ID: <20180601081658.6968-1-bhole_prashant_q7@lab.ntt.co.jp> Cc: Prashant Bhole , Daniel Borkmann , Alexei Starovoitov , Kirill Tkhai , Florian Westphal , netdev@vger.kernel.org To: "David S . Miller" , Eric Dumazet Return-path: Received: from tama50.ecl.ntt.co.jp ([129.60.39.147]:45643 "EHLO tama50.ecl.ntt.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750916AbeFAISg (ORCPT ); Fri, 1 Jun 2018 04:18:36 -0400 Sender: netdev-owner@vger.kernel.org List-ID: In rtnl_newlink(), NULL check is performed on m_ops however member of ops is accessed. Fixed by accessing member of m_ops instead of ops. [ 345.432629] BUG: KASAN: null-ptr-deref in rtnl_newlink+0x400/0x1110 [ 345.432629] Read of size 4 at addr 0000000000000088 by task ip/986 [ 345.432629] [ 345.432629] CPU: 1 PID: 986 Comm: ip Not tainted 4.17.0-rc6+ #9 [ 345.432629] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 [ 345.432629] Call Trace: [ 345.432629] dump_stack+0xc6/0x150 [ 345.432629] ? dump_stack_print_info.cold.0+0x1b/0x1b [ 345.432629] ? kasan_report+0xb4/0x410 [ 345.432629] kasan_report.cold.4+0x8f/0x91 [ 345.432629] ? rtnl_newlink+0x400/0x1110 [ 345.432629] rtnl_newlink+0x400/0x1110 [...] Fixes: ccf8dbcd062a ("rtnetlink: Remove VLA usage") Signed-off-by: Prashant Bhole --- net/core/rtnetlink.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 8ca49a0e13fb..9a1ba2015ad8 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -2936,7 +2936,7 @@ static int rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh, } if (m_ops) { - if (ops->slave_maxtype > RTNL_SLAVE_MAX_TYPE) + if (m_ops->slave_maxtype > RTNL_SLAVE_MAX_TYPE) return -EINVAL; if (m_ops->slave_maxtype && -- 2.17.0