[IPV6]: ipv6_add_addr should install dstentry earlier

ipv6_add_addr allocates a struct inet6_ifaddr and a dstentry, but it
doesn't install the dstentry in ifa->rt until after it releases the
addrconf_hash_lock. This means other CPUs will be able to see the new
address while it hasn't been initialized completely yet.

One possible fix would be to grab the ifp->lock spinlock when
creating the address struct; a simpler fix is to just move the
assignment.

Acked-by: jbeulich@novell.com
Acked-by: okir@suse.de
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 0c5042e7380d391769f8e484132157735cb35e6e..c7852b38e03e451a00923481a327ffa2ce3dd5de 100644 (file)
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -578,6 +578,8 @@ ipv6_add_addr(struct inet6_dev *idev, const struct in6_addr *addr, int pfxlen,
        ifa->flags = flags | IFA_F_TENTATIVE;
        ifa->cstamp = ifa->tstamp = jiffies;
 
+       ifa->rt = rt;
+
        ifa->idev = idev;
        in6_dev_hold(idev);
        /* For caller */
@@ -603,8 +605,6 @@ ipv6_add_addr(struct inet6_dev *idev, const struct in6_addr *addr, int pfxlen,
        }
 #endif
 
-       ifa->rt = rt;
-
        in6_ifa_hold(ifa);
        write_unlock(&idev->lock);
 out2: