1 files changed, 48 insertions, 4 deletions

diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 5cd99271d3a6..c3c359ad66e3 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -351,7 +351,7 @@ int ip_ra_control(struct sock *sk, unsigned char on,
 			return 0;
 		}
 	}
-	if (new_ra == NULL) {
+	if (!new_ra) {
 		spin_unlock_bh(&ip_ra_lock);
 		return -ENOBUFS;
 	}
@@ -387,7 +387,7 @@ void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 				   skb_network_header(skb);
 	serr->port = port;
 
-	if (skb_pull(skb, payload - skb->data) != NULL) {
+	if (skb_pull(skb, payload - skb->data)) {
 		skb_reset_transport_header(skb);
 		if (sock_queue_err_skb(sk, skb) == 0)
 			return;
@@ -432,6 +432,15 @@ void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 port, u32 inf
 		kfree_skb(skb);
 }
 
+/* For some errors we have valid addr_offset even with zero payload and
+ * zero port. Also, addr_offset should be supported if port is set.
+ */
+static inline bool ipv4_datagram_support_addr(struct sock_exterr_skb *serr)
+{
+	return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
+	       serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
+}
+
 /* IPv4 supports cmsg on all imcp errors and some timestamps
  *
  * Timestamp code paths do not initialize the fields expected by cmsg:
@@ -482,7 +491,7 @@ int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 
 	err = -EAGAIN;
 	skb = sock_dequeue_err_skb(sk);
-	if (skb == NULL)
+	if (!skb)
 		goto out;
 
 	copied = skb->len;
@@ -498,7 +507,7 @@ int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 
 	serr = SKB_EXT_ERR(skb);
 
-	if (sin && serr->port) {
+	if (sin && ipv4_datagram_support_addr(serr)) {
 		sin->sin_family = AF_INET;
 		sin->sin_addr.s_addr = *(__be32 *)(skb_network_header(skb) +
 						   serr->addr_offset);
@@ -536,12 +545,34 @@ out:
  *	Socket option code for IP. This is the end of the line after any
  *	TCP,UDP etc options on an IP socket.
  */
+static bool setsockopt_needs_rtnl(int optname)
+{
+	switch (optname) {
+	case IP_ADD_MEMBERSHIP:
+	case IP_ADD_SOURCE_MEMBERSHIP:
+	case IP_BLOCK_SOURCE:
+	case IP_DROP_MEMBERSHIP:
+	case IP_DROP_SOURCE_MEMBERSHIP:
+	case IP_MSFILTER:
+	case IP_UNBLOCK_SOURCE:
+	case MCAST_BLOCK_SOURCE:
+	case MCAST_MSFILTER:
+	case MCAST_JOIN_GROUP:
+	case MCAST_JOIN_SOURCE_GROUP:
+	case MCAST_LEAVE_GROUP:
+	case MCAST_LEAVE_SOURCE_GROUP:
+	case MCAST_UNBLOCK_SOURCE:
+		return true;
+	}
+	return false;
+}
 
 static int do_ip_setsockopt(struct sock *sk, int level,
 			    int optname, char __user *optval, unsigned int optlen)
 {
 	struct inet_sock *inet = inet_sk(sk);
 	int val = 0, err;
+	bool needs_rtnl = setsockopt_needs_rtnl(optname);
 
 	switch (optname) {
 	case IP_PKTINFO:
@@ -560,6 +591,7 @@ static int do_ip_setsockopt(struct sock *sk, int level,
 	case IP_TRANSPARENT:
 	case IP_MINTTL:
 	case IP_NODEFRAG:
+	case IP_BIND_ADDRESS_NO_PORT:
 	case IP_UNICAST_IF:
 	case IP_MULTICAST_TTL:
 	case IP_MULTICAST_ALL:
@@ -584,6 +616,8 @@ static int do_ip_setsockopt(struct sock *sk, int level,
 		return ip_mroute_setsockopt(sk, optname, optval, optlen);
 
 	err = 0;
+	if (needs_rtnl)
+		rtnl_lock();
 	lock_sock(sk);
 
 	switch (optname) {
@@ -708,6 +742,9 @@ static int do_ip_setsockopt(struct sock *sk, int level,
 		}
 		inet->nodefrag = val ? 1 : 0;
 		break;
+	case IP_BIND_ADDRESS_NO_PORT:
+		inet->bind_address_no_port = val ? 1 : 0;
+		break;
 	case IP_MTU_DISCOVER:
 		if (val < IP_PMTUDISC_DONT || val > IP_PMTUDISC_OMIT)
 			goto e_inval;
@@ -1118,10 +1155,14 @@ mc_msf_out:
 		break;
 	}
 	release_sock(sk);
+	if (needs_rtnl)
+		rtnl_unlock();
 	return err;
 
 e_inval:
 	release_sock(sk);
+	if (needs_rtnl)
+		rtnl_unlock();
 	return -EINVAL;
 }
 
@@ -1296,6 +1337,9 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname,
 	case IP_NODEFRAG:
 		val = inet->nodefrag;
 		break;
+	case IP_BIND_ADDRESS_NO_PORT:
+		val = inet->bind_address_no_port;
+		break;
 	case IP_MTU_DISCOVER:
 		val = inet->pmtudisc;
 		break;