From: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Date: Mon, 7 Aug 2017 13:28:39 +0200
Subject: s390/qeth: fix L3 next-hop in xmit qeth hdr
Patch-mainline: v4.13-rc5
Git-commit: ec2c6726322f0d270bab477e4904bf9496f70ee5
References: bsc#1061024 FATE#323301
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 <jwi@linux.vnet.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Fixes: 87e7597b5a3 qeth: Move away from using neighbour entries in qeth_l3_fill_header()
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/s390/net/qeth_l3_main.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- 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 q
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 q
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 */