[SCTP]: IPv4 vs IPv6 addresses mess in sctp_inet[6]addr_event.

All IP addresses that are present in a system are duplicated on
struct sctp_sockaddr_entry. They are linked in the global list
called sctp_local_addr_list. And this struct unions IPv4 and IPv6
addresses.

So, there can be rare case, when a sockaddr_in.sin_addr coincides
with the corresponding part of the sockaddr_in6 and the notifier
for IPv4 will carry away an IPv6 entry.

The fix is to check the family before comparing the addresses.
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Signed-off-by: NVlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/sctp/ipv6.c

@@ -110,7 +110,8 @@ static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev,
 		spin_lock_bh(&sctp_local_addr_lock);
 		list_for_each_entry_safe(addr, temp,
 					&sctp_local_addr_list, list) {
-			if (ipv6_addr_equal(&addr->a.v6.sin6_addr,
+			if (addr->a.sa.sa_family == AF_INET6 &&
+					ipv6_addr_equal(&addr->a.v6.sin6_addr,
 						&ifa->addr)) {
 				found = 1;
 				addr->valid = 0;

net/sctp/protocol.c

@@ -647,7 +647,9 @@ static int sctp_inetaddr_event(struct notifier_block *this, unsigned long ev,
 		spin_lock_bh(&sctp_local_addr_lock);
 		list_for_each_entry_safe(addr, temp,
 					&sctp_local_addr_list, list) {
-			if (addr->a.v4.sin_addr.s_addr == ifa->ifa_local) {
+			if (addr->a.sa.sa_family == AF_INET &&
+					addr->a.v4.sin_addr.s_addr ==
+					ifa->ifa_local) {
 				found = 1;
 				addr->valid = 0;
 				list_del_rcu(&addr->list);