sctp: allocate sctp_sockaddr_entry with kzalloc

The similar issue as fixed in Commit 4a2eb0c3 ("sctp: initialize
sin6_flowinfo for ipv6 addrs in sctp_inet6addr_event") also exists
in sctp_inetaddr_event, as Alexander noticed.

To fix it, allocate sctp_sockaddr_entry with kzalloc for both sctp
ipv4 and ipv6 addresses, as does in sctp_v4/6_copy_addrlist().
Reported-by: NAlexander Potapenko <glider@google.com>
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Reported-by: syzbot+ae0c70c0c2d40c51bb92@syzkaller.appspotmail.com
Acked-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/sctp/ipv6.c

@@ -97,11 +97,9 @@ static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev,
 
 	switch (ev) {
 	case NETDEV_UP:
-		addr = kmalloc(sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
+		addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
 		if (addr) {
 			addr->a.v6.sin6_family = AF_INET6;
-			addr->a.v6.sin6_port = 0;
-			addr->a.v6.sin6_flowinfo = 0;
 			addr->a.v6.sin6_addr = ifa->addr;
 			addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
 			addr->valid = 1;
@@ -434,7 +432,6 @@ static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 		addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
 		if (addr) {
 			addr->a.v6.sin6_family = AF_INET6;
-			addr->a.v6.sin6_port = 0;
 			addr->a.v6.sin6_addr = ifp->addr;
 			addr->a.v6.sin6_scope_id = dev->ifindex;
 			addr->valid = 1;

net/sctp/protocol.c

@@ -101,7 +101,6 @@ static void sctp_v4_copy_addrlist(struct list_head *addrlist,
 		addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
 		if (addr) {
 			addr->a.v4.sin_family = AF_INET;
-			addr->a.v4.sin_port = 0;
 			addr->a.v4.sin_addr.s_addr = ifa->ifa_local;
 			addr->valid = 1;
 			INIT_LIST_HEAD(&addr->list);
@@ -776,10 +775,9 @@ static int sctp_inetaddr_event(struct notifier_block *this, unsigned long ev,
 
 	switch (ev) {
 	case NETDEV_UP:
-		addr = kmalloc(sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
+		addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
 		if (addr) {
 			addr->a.v4.sin_family = AF_INET;
-			addr->a.v4.sin_port = 0;
 			addr->a.v4.sin_addr.s_addr = ifa->ifa_local;
 			addr->valid = 1;
 			spin_lock_bh(&net->sctp.local_addr_lock);