1 files changed, 95 insertions, 40 deletions
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 86d282618515..d0bffcfa56d8 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -121,13 +121,12 @@
 #endif
 
 struct udp_table udp_table __read_mostly;
-EXPORT_SYMBOL(udp_table);
 
 long sysctl_udp_mem[3] __read_mostly;
-EXPORT_SYMBOL(sysctl_udp_mem);
+EXPORT_IPV6_MOD(sysctl_udp_mem);
 
 atomic_long_t udp_memory_allocated ____cacheline_aligned_in_smp;
-EXPORT_SYMBOL(udp_memory_allocated);
+EXPORT_IPV6_MOD(udp_memory_allocated);
 DEFINE_PER_CPU(int, udp_memory_per_cpu_fw_alloc);
 EXPORT_PER_CPU_SYMBOL_GPL(udp_memory_per_cpu_fw_alloc);
 
@@ -352,7 +351,7 @@ fail_unlock:
 fail:
 	return error;
 }
-EXPORT_SYMBOL(udp_lib_get_port);
+EXPORT_IPV6_MOD(udp_lib_get_port);
 
 int udp_v4_get_port(struct sock *sk, unsigned short snum)
 {
@@ -418,7 +417,50 @@ u32 udp_ehashfn(const struct net *net, const __be32 laddr, const __u16 lport,
 	return __inet_ehashfn(laddr, lport, faddr, fport,
 			      udp_ehash_secret + net_hash_mix(net));
 }
-EXPORT_SYMBOL(udp_ehashfn);
+EXPORT_IPV6_MOD(udp_ehashfn);
+
+/**
+ * udp4_lib_lookup1() - Simplified lookup using primary hash (destination port)
+ * @net:	Network namespace
+ * @saddr:	Source address, network order
+ * @sport:	Source port, network order
+ * @daddr:	Destination address, network order
+ * @hnum:	Destination port, host order
+ * @dif:	Destination interface index
+ * @sdif:	Destination bridge port index, if relevant
+ * @udptable:	Set of UDP hash tables
+ *
+ * Simplified lookup to be used as fallback if no sockets are found due to a
+ * potential race between (receive) address change, and lookup happening before
+ * the rehash operation. This function ignores SO_REUSEPORT groups while scoring
+ * result sockets, because if we have one, we don't need the fallback at all.
+ *
+ * Called under rcu_read_lock().
+ *
+ * Return: socket with highest matching score if any, NULL if none
+ */
+static struct sock *udp4_lib_lookup1(const struct net *net,
+				     __be32 saddr, __be16 sport,
+				     __be32 daddr, unsigned int hnum,
+				     int dif, int sdif,
+				     const struct udp_table *udptable)
+{
+	unsigned int slot = udp_hashfn(net, hnum, udptable->mask);
+	struct udp_hslot *hslot = &udptable->hash[slot];
+	struct sock *sk, *result = NULL;
+	int score, badness = 0;
+
+	sk_for_each_rcu(sk, &hslot->head) {
+		score = compute_score(sk, net,
+				      saddr, sport, daddr, hnum, dif, sdif);
+		if (score > badness) {
+			result = sk;
+			badness = score;
+		}
+	}
+
+	return result;
+}
 
 /* called with rcu_read_lock() */
 static struct sock *udp4_lib_lookup2(const struct net *net,
@@ -610,7 +652,7 @@ void udp_lib_hash4(struct sock *sk, u16 hash)
 
 	spin_unlock_bh(&hslot->lock);
 }
-EXPORT_SYMBOL(udp_lib_hash4);
+EXPORT_IPV6_MOD(udp_lib_hash4);
 
 /* call with sock lock */
 void udp4_hash4(struct sock *sk)
@@ -626,7 +668,7 @@ void udp4_hash4(struct sock *sk)
 
 	udp_lib_hash4(sk, hash);
 }
-EXPORT_SYMBOL(udp4_hash4);
+EXPORT_IPV6_MOD(udp4_hash4);
 #endif /* CONFIG_BASE_SMALL */
 
 /* UDP is nearly always wildcards out the wazoo, it makes no sense to try
@@ -681,6 +723,19 @@ struct sock *__udp4_lib_lookup(const struct net *net, __be32 saddr,
 	result = udp4_lib_lookup2(net, saddr, sport,
 				  htonl(INADDR_ANY), hnum, dif, sdif,
 				  hslot2, skb);
+	if (!IS_ERR_OR_NULL(result))
+		goto done;
+
+	/* Primary hash (destination port) lookup as fallback for this race:
+	 *   1. __ip4_datagram_connect() sets sk_rcv_saddr
+	 *   2. lookup (this function): new sk_rcv_saddr, hashes not updated yet
+	 *   3. rehash operation updating _secondary and four-tuple_ hashes
+	 * The primary hash doesn't need an update after 1., so, thanks to this
+	 * further step, 1. and 3. don't need to be atomic against the lookup.
+	 */
+	result = udp4_lib_lookup1(net, saddr, sport, daddr, hnum, dif, sdif,
+				  udptable);
+
 done:
 	if (IS_ERR(result))
 		return NULL;
@@ -753,11 +808,11 @@ static inline bool __udp_is_mcast_sock(struct net *net, const struct sock *sk,
 }
 
 DEFINE_STATIC_KEY_FALSE(udp_encap_needed_key);
-EXPORT_SYMBOL(udp_encap_needed_key);
+EXPORT_IPV6_MOD(udp_encap_needed_key);
 
 #if IS_ENABLED(CONFIG_IPV6)
 DEFINE_STATIC_KEY_FALSE(udpv6_encap_needed_key);
-EXPORT_SYMBOL(udpv6_encap_needed_key);
+EXPORT_IPV6_MOD(udpv6_encap_needed_key);
 #endif
 
 void udp_encap_enable(void)
@@ -985,7 +1040,7 @@ void udp_flush_pending_frames(struct sock *sk)
 		ip_flush_pending_frames(sk);
 	}
 }
-EXPORT_SYMBOL(udp_flush_pending_frames);
+EXPORT_IPV6_MOD(udp_flush_pending_frames);
 
 /**
  * 	udp4_hwcsum  -  handle outgoing HW checksumming
@@ -1085,9 +1140,9 @@ static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4,
 		const int hlen = skb_network_header_len(skb) +
 				 sizeof(struct udphdr);
 
-		if (hlen + cork->gso_size > cork->fragsize) {
+		if (hlen + min(datalen, cork->gso_size) > cork->fragsize) {
 			kfree_skb(skb);
-			return -EINVAL;
+			return -EMSGSIZE;
 		}
 		if (datalen > cork->gso_size * UDP_MAX_SEGMENTS) {
 			kfree_skb(skb);
@@ -1173,7 +1228,7 @@ out:
 	WRITE_ONCE(up->pending, 0);
 	return err;
 }
-EXPORT_SYMBOL(udp_push_pending_frames);
+EXPORT_IPV6_MOD(udp_push_pending_frames);
 
 static int __udp_cmsg_send(struct cmsghdr *cmsg, u16 *gso_size)
 {
@@ -1210,7 +1265,7 @@ int udp_cmsg_send(struct sock *sk, struct msghdr *msg, u16 *gso_size)
 
 	return need_ip;
 }
-EXPORT_SYMBOL_GPL(udp_cmsg_send);
+EXPORT_IPV6_MOD_GPL(udp_cmsg_send);
 
 int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 {
@@ -1225,7 +1280,7 @@ int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 	int free = 0;
 	int connected = 0;
 	__be32 daddr, faddr, saddr;
-	u8 tos, scope;
+	u8 scope;
 	__be16 dport;
 	int err, is_udplite = IS_UDPLITE(sk);
 	int corkreq = udp_test_bit(CORK, sk) || msg->msg_flags & MSG_MORE;
@@ -1349,7 +1404,6 @@ int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 		faddr = ipc.opt->opt.faddr;
 		connected = 0;
 	}
-	tos = get_rttos(&ipc, inet);
 	scope = ip_sendmsg_scope(inet, &ipc, msg);
 	if (scope == RT_SCOPE_LINK)
 		connected = 0;
@@ -1386,7 +1440,8 @@ int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 
 		fl4 = &fl4_stack;
 
-		flowi4_init_output(fl4, ipc.oif, ipc.sockc.mark, tos, scope,
+		flowi4_init_output(fl4, ipc.oif, ipc.sockc.mark,
+				   ipc.tos & INET_DSCP_MASK, scope,
 				   sk->sk_protocol, flow_flags, faddr, saddr,
 				   dport, inet->inet_sport, sk->sk_uid);
 
@@ -1505,7 +1560,7 @@ void udp_splice_eof(struct socket *sock)
 		udp_push_pending_frames(sk);
 	release_sock(sk);
 }
-EXPORT_SYMBOL_GPL(udp_splice_eof);
+EXPORT_IPV6_MOD_GPL(udp_splice_eof);
 
 #define UDP_SKB_IS_STATELESS 0x80000000
 
@@ -1622,7 +1677,7 @@ void udp_skb_destructor(struct sock *sk, struct sk_buff *skb)
 	prefetch(&skb->data);
 	udp_rmem_release(sk, udp_skb_truesize(skb), 1, false);
 }
-EXPORT_SYMBOL(udp_skb_destructor);
+EXPORT_IPV6_MOD(udp_skb_destructor);
 
 /* as above, but the caller held the rx queue lock, too */
 static void udp_skb_dtor_locked(struct sock *sk, struct sk_buff *skb)
@@ -1729,7 +1784,7 @@ drop:
 	busylock_release(busy);
 	return err;
 }
-EXPORT_SYMBOL_GPL(__udp_enqueue_schedule_skb);
+EXPORT_IPV6_MOD_GPL(__udp_enqueue_schedule_skb);
 
 void udp_destruct_common(struct sock *sk)
 {
@@ -1745,7 +1800,7 @@ void udp_destruct_common(struct sock *sk)
 	}
 	udp_rmem_release(sk, total, 0, true);
 }
-EXPORT_SYMBOL_GPL(udp_destruct_common);
+EXPORT_IPV6_MOD_GPL(udp_destruct_common);
 
 static void udp_destruct_sock(struct sock *sk)
 {
@@ -1776,7 +1831,7 @@ void skb_consume_udp(struct sock *sk, struct sk_buff *skb, int len)
 		skb_release_head_state(skb);
 	__consume_stateless_skb(skb);
 }
-EXPORT_SYMBOL_GPL(skb_consume_udp);
+EXPORT_IPV6_MOD_GPL(skb_consume_udp);
 
 static struct sk_buff *__first_packet_length(struct sock *sk,
 					     struct sk_buff_head *rcvq,
@@ -1793,7 +1848,7 @@ static struct sk_buff *__first_packet_length(struct sock *sk,
 			atomic_inc(&sk->sk_drops);
 			__skb_unlink(skb, rcvq);
 			*total += skb->truesize;
-			kfree_skb(skb);
+			kfree_skb_reason(skb, SKB_DROP_REASON_UDP_CSUM);
 		} else {
 			udp_skb_csum_unnecessary_set(skb);
 			break;
@@ -1858,7 +1913,7 @@ int udp_ioctl(struct sock *sk, int cmd, int *karg)
 
 	return 0;
 }
-EXPORT_SYMBOL(udp_ioctl);
+EXPORT_IPV6_MOD(udp_ioctl);
 
 struct sk_buff *__skb_recv_udp(struct sock *sk, unsigned int flags,
 			       int *off, int *err)
@@ -1947,14 +2002,14 @@ try_again:
 		__UDP_INC_STATS(net, UDP_MIB_CSUMERRORS, is_udplite);
 		__UDP_INC_STATS(net, UDP_MIB_INERRORS, is_udplite);
 		atomic_inc(&sk->sk_drops);
-		kfree_skb(skb);
+		kfree_skb_reason(skb, SKB_DROP_REASON_UDP_CSUM);
 		goto try_again;
 	}
 
 	WARN_ON_ONCE(!skb_set_owner_sk_safe(skb, sk));
 	return recv_actor(sk, skb);
 }
-EXPORT_SYMBOL(udp_read_skb);
+EXPORT_IPV6_MOD(udp_read_skb);
 
 /*
  * 	This should be easy, if there is something there we
@@ -2062,7 +2117,7 @@ csum_copy_err:
 		UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
 		UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
 	}
-	kfree_skb(skb);
+	kfree_skb_reason(skb, SKB_DROP_REASON_UDP_CSUM);
 
 	/* starting over for a new packet, but check if we need to yield */
 	cond_resched();
@@ -2081,7 +2136,7 @@ int udp_pre_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 
 	return BPF_CGROUP_RUN_PROG_INET4_CONNECT_LOCK(sk, uaddr, &addr_len);
 }
-EXPORT_SYMBOL(udp_pre_connect);
+EXPORT_IPV6_MOD(udp_pre_connect);
 
 static int udp_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 {
@@ -2130,7 +2185,7 @@ int udp_disconnect(struct sock *sk, int flags)
 	release_sock(sk);
 	return 0;
 }
-EXPORT_SYMBOL(udp_disconnect);
+EXPORT_IPV6_MOD(udp_disconnect);
 
 void udp_lib_unhash(struct sock *sk)
 {
@@ -2160,7 +2215,7 @@ void udp_lib_unhash(struct sock *sk)
 		spin_unlock_bh(&hslot->lock);
 	}
 }
-EXPORT_SYMBOL(udp_lib_unhash);
+EXPORT_IPV6_MOD(udp_lib_unhash);
 
 /*
  * inet_rcv_saddr was changed, we must rehash secondary hash
@@ -2224,7 +2279,7 @@ void udp_lib_rehash(struct sock *sk, u16 newhash, u16 newhash4)
 		}
 	}
 }
-EXPORT_SYMBOL(udp_lib_rehash);
+EXPORT_IPV6_MOD(udp_lib_rehash);
 
 void udp_v4_rehash(struct sock *sk)
 {
@@ -2429,7 +2484,7 @@ bool udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst)
 	}
 	return false;
 }
-EXPORT_SYMBOL(udp_sk_rx_dst_set);
+EXPORT_IPV6_MOD(udp_sk_rx_dst_set);
 
 /*
  *	Multicasts and broadcasts go to each listener.
@@ -2985,7 +3040,7 @@ int udp_lib_setsockopt(struct sock *sk, int level, int optname,
 
 	return err;
 }
-EXPORT_SYMBOL(udp_lib_setsockopt);
+EXPORT_IPV6_MOD(udp_lib_setsockopt);
 
 int udp_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
 		   unsigned int optlen)
@@ -3056,7 +3111,7 @@ int udp_lib_getsockopt(struct sock *sk, int level, int optname,
 		return -EFAULT;
 	return 0;
 }
-EXPORT_SYMBOL(udp_lib_getsockopt);
+EXPORT_IPV6_MOD(udp_lib_getsockopt);
 
 int udp_getsockopt(struct sock *sk, int level, int optname,
 		   char __user *optval, int __user *optlen)
@@ -3098,7 +3153,7 @@ __poll_t udp_poll(struct file *file, struct socket *sock, poll_table *wait)
 	return mask;
 
 }
-EXPORT_SYMBOL(udp_poll);
+EXPORT_IPV6_MOD(udp_poll);
 
 int udp_abort(struct sock *sk, int err)
 {
@@ -3121,7 +3176,7 @@ out:
 
 	return 0;
 }
-EXPORT_SYMBOL_GPL(udp_abort);
+EXPORT_IPV6_MOD_GPL(udp_abort);
 
 struct proto udp_prot = {
 	.name			= "UDP",
@@ -3255,7 +3310,7 @@ void *udp_seq_start(struct seq_file *seq, loff_t *pos)
 
 	return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
 }
-EXPORT_SYMBOL(udp_seq_start);
+EXPORT_IPV6_MOD(udp_seq_start);
 
 void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 {
@@ -3269,7 +3324,7 @@ void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 	++*pos;
 	return sk;
 }
-EXPORT_SYMBOL(udp_seq_next);
+EXPORT_IPV6_MOD(udp_seq_next);
 
 void udp_seq_stop(struct seq_file *seq, void *v)
 {
@@ -3281,7 +3336,7 @@ void udp_seq_stop(struct seq_file *seq, void *v)
 	if (state->bucket <= udptable->mask)
 		spin_unlock_bh(&udptable->hash[state->bucket].lock);
 }
-EXPORT_SYMBOL(udp_seq_stop);
+EXPORT_IPV6_MOD(udp_seq_stop);
 
 /* ------------------------------------------------------------------------ */
 static void udp4_format_sock(struct sock *sp, struct seq_file *f,
@@ -3560,7 +3615,7 @@ const struct seq_operations udp_seq_ops = {
 	.stop		= udp_seq_stop,
 	.show		= udp4_seq_show,
 };
-EXPORT_SYMBOL(udp_seq_ops);
+EXPORT_IPV6_MOD(udp_seq_ops);
 
 static struct udp_seq_afinfo udp4_seq_afinfo = {
 	.family		= AF_INET,