Commit ec2c6726 authored Aug 07, 2017 by Julian Wiedmann Committed by David S. Miller Aug 07, 2017

s390/qeth: fix L3 next-hop in xmit qeth hdr



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: 87e7597b qeth: Move away from using neighbour entries in qeth_l3_fill_header()
Signed-off-by: David S. Miller <davem@davemloft.net>

parent c0e0fb83

drivers/s390/net/qeth_l3_main.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -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 */