IPVS: fix NULL ptr dereference in ip_vs_ctl.c ip_vs_genl_dump_daemons()

ipvsadm -ln --daemon will trigger a Null pointer exception because
ip_vs_genl_dump_daemons() uses skb_net() instead of skb_sknet().

To prevent others from NULL ptr a check is made in ip_vs.h skb_net().

Signed-off-by: Hans Schillstrom <hans.schillstrom@ericsson.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Patrick McHardy <kaber@trash.net>

diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h
index 30b49ed..4d1b71a 100644 (file)
--- a/include/net/ip_vs.h
+++ b/include/net/ip_vs.h
@@ -52,7 +52,7 @@ static inline struct net *skb_net(const struct sk_buff *skb)
         */
        if (likely(skb->dev && skb->dev->nd_net))
                return dev_net(skb->dev);
-       if (skb_dst(skb)->dev)
+       if (skb_dst(skb) && skb_dst(skb)->dev)
                return dev_net(skb_dst(skb)->dev);
        WARN(skb->sk, "Maybe skb_sknet should be used in %s() at line:%d\n",
                      __func__, __LINE__);

diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
index 33733c8..ae47090 100644 (file)
--- a/net/netfilter/ipvs/ip_vs_ctl.c
+++ b/net/netfilter/ipvs/ip_vs_ctl.c
@@ -3120,7 +3120,7 @@ nla_put_failure:
 static int ip_vs_genl_dump_daemons(struct sk_buff *skb,
                                   struct netlink_callback *cb)
 {
-       struct net *net = skb_net(skb);
+       struct net *net = skb_sknet(skb);
        struct netns_ipvs *ipvs = net_ipvs(net);
 
        mutex_lock(&__ip_vs_mutex);