From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ursula Braun Subject: [PATCH net 1/1] s390/qeth: fix L3 next-hop in xmit qeth hdr Date: Mon, 7 Aug 2017 13:28:39 +0200 Message-ID: <20170807112839.91254-2-ubraun@linux.vnet.ibm.com> References: <20170807112839.91254-1-ubraun@linux.vnet.ibm.com> Cc: netdev@vger.kernel.org, linux-s390@vger.kernel.org, jwi@linux.vnet.ibm.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, raspl@linux.vnet.ibm.com, ubraun@linux.vnet.ibm.com To: davem@davemloft.net Return-path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:42757 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752878AbdHGL2u (ORCPT ); Mon, 7 Aug 2017 07:28:50 -0400 Received: from pps.filterd (m0098416.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v77BSiDr136368 for ; Mon, 7 Aug 2017 07:28:50 -0400 Received: from e06smtp10.uk.ibm.com (e06smtp10.uk.ibm.com [195.75.94.106]) by mx0b-001b2d01.pphosted.com with ESMTP id 2c6kfha4p0-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Mon, 07 Aug 2017 07:28:49 -0400 Received: from localhost by e06smtp10.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 7 Aug 2017 12:28:48 +0100 In-Reply-To: <20170807112839.91254-1-ubraun@linux.vnet.ibm.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Julian Wiedmann On L3, the qeth_hdr struct needs to be filled with the next-hop IP address. The current code accesses rtable->rt_gateway without checking that rtable is a valid address. The accidental access to a lowcore area results in a random next-hop address in the qeth_hdr. rtable (or more precisely, skb_dst(skb)) can be NULL in rare cases (for instance together with AF_PACKET sockets). This patch adds the missing NULL-ptr checks. Signed-off-by: Julian Wiedmann Signed-off-by: Ursula Braun Fixes: 87e7597b5a3 qeth: Move away from using neighbour entries in qeth_l3_fill_header() --- drivers/s390/net/qeth_l3_main.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/s390/net/qeth_l3_main.c b/drivers/s390/net/qeth_l3_main.c index 8975cd321390..d42e758518ed 100644 --- a/drivers/s390/net/qeth_l3_main.c +++ b/drivers/s390/net/qeth_l3_main.c @@ -2512,7 +2512,7 @@ static void qeth_l3_fill_header(struct qeth_card *card, struct qeth_hdr *hdr, struct rtable *rt = (struct rtable *) dst; __be32 *pkey = &ip_hdr(skb)->daddr; - if (rt->rt_gateway) + if (rt && rt->rt_gateway) pkey = &rt->rt_gateway; /* IPv4 */ @@ -2523,7 +2523,7 @@ static void qeth_l3_fill_header(struct qeth_card *card, struct qeth_hdr *hdr, struct rt6_info *rt = (struct rt6_info *) dst; struct in6_addr *pkey = &ipv6_hdr(skb)->daddr; - if (!ipv6_addr_any(&rt->rt6i_gateway)) + if (rt && !ipv6_addr_any(&rt->rt6i_gateway)) pkey = &rt->rt6i_gateway; /* IPv6 */ -- 2.11.2