ipv6: Fix Smatch warning.
authorLi Wei <lw@cn.fujitsu.com>
Wed, 7 Mar 2012 14:58:07 +0000 (14:58 +0000)
committerDavid S. Miller <davem@davemloft.net>
Sun, 11 Mar 2012 22:57:11 +0000 (15:57 -0700)
With commit d6ddef9e641d(IPv6: Fix not join all-router mcast group
when forwarding set.) I check 'dev' after it's dereference that
leads to a Smatch complaint:

net/ipv6/addrconf.c:438 ipv6_add_dev()
 warn: variable dereferenced before check 'dev' (see line 432)

net/ipv6/addrconf.c
   431 /* protected by rtnl_lock */
   432 rcu_assign_pointer(dev->ip6_ptr, ndev);
                                   ^^^^^^^^^^^^
Old dereference.

   433
   434 /* Join all-node multicast group */
   435 ipv6_dev_mc_inc(dev, &in6addr_linklocal_allnodes);
   436
   437 /* Join all-router multicast group if forwarding is set
*/
   438 if (ndev->cnf.forwarding && dev && (dev->flags &
IFF_MULTICAST))
                                            ^^^

Remove the check to avoid the complaint as 'dev' can't be NULL.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Li Wei <lw@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/ipv6/addrconf.c

index 6b8ebc5da0e1344ad58994e327ba42cac44f3ac3..6a3bb6077e19715bf2732bbce3d1c09d06aed104 100644 (file)
@@ -435,7 +435,7 @@ static struct inet6_dev * ipv6_add_dev(struct net_device *dev)
        ipv6_dev_mc_inc(dev, &in6addr_linklocal_allnodes);
 
        /* Join all-router multicast group if forwarding is set */
-       if (ndev->cnf.forwarding && dev && (dev->flags & IFF_MULTICAST))
+       if (ndev->cnf.forwarding && (dev->flags & IFF_MULTICAST))
                ipv6_dev_mc_inc(dev, &in6addr_linklocal_allrouters);
 
        return ndev;