From: Julian Wiedmann <[email protected]> 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 <[email protected]> Signed-off-by: Ursula Braun <[email protected]> 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
