1 files changed, 45 insertions, 30 deletions

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index f98a1882e537..42187a3b82f4 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -326,7 +326,7 @@ void tcp_enter_memory_pressure(struct sock *sk)
 {
 	unsigned long val;
 
-	if (tcp_memory_pressure)
+	if (READ_ONCE(tcp_memory_pressure))
 		return;
 	val = jiffies;
 
@@ -341,7 +341,7 @@ void tcp_leave_memory_pressure(struct sock *sk)
 {
 	unsigned long val;
 
-	if (!tcp_memory_pressure)
+	if (!READ_ONCE(tcp_memory_pressure))
 		return;
 	val = xchg(&tcp_memory_pressure, 0);
 	if (val)
@@ -450,8 +450,8 @@ void tcp_init_sock(struct sock *sk)
 
 	icsk->icsk_sync_mss = tcp_sync_mss;
 
-	sk->sk_sndbuf = sock_net(sk)->ipv4.sysctl_tcp_wmem[1];
-	sk->sk_rcvbuf = sock_net(sk)->ipv4.sysctl_tcp_rmem[1];
+	WRITE_ONCE(sk->sk_sndbuf, sock_net(sk)->ipv4.sysctl_tcp_wmem[1]);
+	WRITE_ONCE(sk->sk_rcvbuf, sock_net(sk)->ipv4.sysctl_tcp_rmem[1]);
 
 	sk_sockets_allocated_inc(sk);
 	sk->sk_route_forced_caps = NETIF_F_GSO;
@@ -477,7 +477,7 @@ static void tcp_tx_timestamp(struct sock *sk, u16 tsflags)
 static inline bool tcp_stream_is_readable(const struct tcp_sock *tp,
 					  int target, struct sock *sk)
 {
-	return (tp->rcv_nxt - tp->copied_seq >= target) ||
+	return (READ_ONCE(tp->rcv_nxt) - READ_ONCE(tp->copied_seq) >= target) ||
 		(sk->sk_prot->stream_memory_read ?
 		sk->sk_prot->stream_memory_read(sk) : false);
 }
@@ -543,10 +543,10 @@ __poll_t tcp_poll(struct file *file, struct socket *sock, poll_table *wait)
 
 	/* Connected or passive Fast Open socket? */
 	if (state != TCP_SYN_SENT &&
-	    (state != TCP_SYN_RECV || tp->fastopen_rsk)) {
+	    (state != TCP_SYN_RECV || rcu_access_pointer(tp->fastopen_rsk))) {
 		int target = sock_rcvlowat(sk, 0, INT_MAX);
 
-		if (tp->urg_seq == tp->copied_seq &&
+		if (READ_ONCE(tp->urg_seq) == READ_ONCE(tp->copied_seq) &&
 		    !sock_flag(sk, SOCK_URGINLINE) &&
 		    tp->urg_data)
 			target++;
@@ -607,7 +607,8 @@ int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg)
 		unlock_sock_fast(sk, slow);
 		break;
 	case SIOCATMARK:
-		answ = tp->urg_data && tp->urg_seq == tp->copied_seq;
+		answ = tp->urg_data &&
+		       READ_ONCE(tp->urg_seq) == READ_ONCE(tp->copied_seq);
 		break;
 	case SIOCOUTQ:
 		if (sk->sk_state == TCP_LISTEN)
@@ -616,7 +617,7 @@ int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg)
 		if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
 			answ = 0;
 		else
-			answ = tp->write_seq - tp->snd_una;
+			answ = READ_ONCE(tp->write_seq) - tp->snd_una;
 		break;
 	case SIOCOUTQNSD:
 		if (sk->sk_state == TCP_LISTEN)
@@ -625,7 +626,8 @@ int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg)
 		if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
 			answ = 0;
 		else
-			answ = tp->write_seq - tp->snd_nxt;
+			answ = READ_ONCE(tp->write_seq) -
+			       READ_ONCE(tp->snd_nxt);
 		break;
 	default:
 		return -ENOIOCTLCMD;
@@ -657,7 +659,7 @@ static void skb_entail(struct sock *sk, struct sk_buff *skb)
 	tcb->sacked  = 0;
 	__skb_header_release(skb);
 	tcp_add_write_queue_tail(sk, skb);
-	sk->sk_wmem_queued += skb->truesize;
+	sk_wmem_queued_add(sk, skb->truesize);
 	sk_mem_charge(sk, skb->truesize);
 	if (tp->nonagle & TCP_NAGLE_PUSH)
 		tp->nonagle &= ~TCP_NAGLE_PUSH;
@@ -1032,10 +1034,10 @@ new_segment:
 		skb->len += copy;
 		skb->data_len += copy;
 		skb->truesize += copy;
-		sk->sk_wmem_queued += copy;
+		sk_wmem_queued_add(sk, copy);
 		sk_mem_charge(sk, copy);
 		skb->ip_summed = CHECKSUM_PARTIAL;
-		tp->write_seq += copy;
+		WRITE_ONCE(tp->write_seq, tp->write_seq + copy);
 		TCP_SKB_CB(skb)->end_seq += copy;
 		tcp_skb_pcount_set(skb, 0);
 
@@ -1362,7 +1364,7 @@ new_segment:
 		if (!copied)
 			TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH;
 
-		tp->write_seq += copy;
+		WRITE_ONCE(tp->write_seq, tp->write_seq + copy);
 		TCP_SKB_CB(skb)->end_seq += copy;
 		tcp_skb_pcount_set(skb, 0);
 
@@ -1668,9 +1670,9 @@ int tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
 		sk_eat_skb(sk, skb);
 		if (!desc->count)
 			break;
-		tp->copied_seq = seq;
+		WRITE_ONCE(tp->copied_seq, seq);
 	}
-	tp->copied_seq = seq;
+	WRITE_ONCE(tp->copied_seq, seq);
 
 	tcp_rcv_space_adjust(sk);
 
@@ -1699,7 +1701,7 @@ int tcp_set_rcvlowat(struct sock *sk, int val)
 	else
 		cap = sock_net(sk)->ipv4.sysctl_tcp_rmem[2] >> 1;
 	val = min(val, cap);
-	sk->sk_rcvlowat = val ? : 1;
+	WRITE_ONCE(sk->sk_rcvlowat, val ? : 1);
 
 	/* Check if we need to signal EPOLLIN right now */
 	tcp_data_ready(sk);
@@ -1709,7 +1711,7 @@ int tcp_set_rcvlowat(struct sock *sk, int val)
 
 	val <<= 1;
 	if (val > sk->sk_rcvbuf) {
-		sk->sk_rcvbuf = val;
+		WRITE_ONCE(sk->sk_rcvbuf, val);
 		tcp_sk(sk)->window_clamp = tcp_win_from_space(sk, val);
 	}
 	return 0;
@@ -1819,7 +1821,7 @@ static int tcp_zerocopy_receive(struct sock *sk,
 out:
 	up_read(&current->mm->mmap_sem);
 	if (length) {
-		tp->copied_seq = seq;
+		WRITE_ONCE(tp->copied_seq, seq);
 		tcp_rcv_space_adjust(sk);
 
 		/* Clean up data we have read: This will do ACK frames. */
@@ -2117,7 +2119,7 @@ found_ok_skb:
 			if (urg_offset < used) {
 				if (!urg_offset) {
 					if (!sock_flag(sk, SOCK_URGINLINE)) {
-						++*seq;
+						WRITE_ONCE(*seq, *seq + 1);
 						urg_hole++;
 						offset++;
 						used--;
@@ -2139,7 +2141,7 @@ found_ok_skb:
 			}
 		}
 
-		*seq += used;
+		WRITE_ONCE(*seq, *seq + used);
 		copied += used;
 		len -= used;
 
@@ -2166,7 +2168,7 @@ skip_copy:
 
 found_fin_ok:
 		/* Process the FIN. */
-		++*seq;
+		WRITE_ONCE(*seq, *seq + 1);
 		if (!(flags & MSG_PEEK))
 			sk_eat_skb(sk, skb);
 		break;
@@ -2487,7 +2489,10 @@ adjudge_to_death:
 	}
 
 	if (sk->sk_state == TCP_CLOSE) {
-		struct request_sock *req = tcp_sk(sk)->fastopen_rsk;
+		struct request_sock *req;
+
+		req = rcu_dereference_protected(tcp_sk(sk)->fastopen_rsk,
+						lockdep_sock_is_held(sk));
 		/* We could get here with a non-NULL req if the socket is
 		 * aborted (e.g., closed with unread data) before 3WHS
 		 * finishes.
@@ -2559,6 +2564,7 @@ int tcp_disconnect(struct sock *sk, int flags)
 	struct inet_connection_sock *icsk = inet_csk(sk);
 	struct tcp_sock *tp = tcp_sk(sk);
 	int old_state = sk->sk_state;
+	u32 seq;
 
 	if (old_state != TCP_CLOSE)
 		tcp_set_state(sk, TCP_CLOSE);
@@ -2585,7 +2591,7 @@ int tcp_disconnect(struct sock *sk, int flags)
 		__kfree_skb(sk->sk_rx_skb_cache);
 		sk->sk_rx_skb_cache = NULL;
 	}
-	tp->copied_seq = tp->rcv_nxt;
+	WRITE_ONCE(tp->copied_seq, tp->rcv_nxt);
 	tp->urg_data = 0;
 	tcp_write_queue_purge(sk);
 	tcp_fastopen_active_disable_ofo_check(sk);
@@ -2601,9 +2607,12 @@ int tcp_disconnect(struct sock *sk, int flags)
 	tp->srtt_us = 0;
 	tp->mdev_us = jiffies_to_usecs(TCP_TIMEOUT_INIT);
 	tp->rcv_rtt_last_tsecr = 0;
-	tp->write_seq += tp->max_window + 2;
-	if (tp->write_seq == 0)
-		tp->write_seq = 1;
+
+	seq = tp->write_seq + tp->max_window + 2;
+	if (!seq)
+		seq = 1;
+	WRITE_ONCE(tp->write_seq, seq);
+
 	icsk->icsk_backoff = 0;
 	tp->snd_cwnd = 2;
 	icsk->icsk_probes_out = 0;
@@ -2930,9 +2939,9 @@ static int do_tcp_setsockopt(struct sock *sk, int level,
 		if (sk->sk_state != TCP_CLOSE)
 			err = -EPERM;
 		else if (tp->repair_queue == TCP_SEND_QUEUE)
-			tp->write_seq = val;
+			WRITE_ONCE(tp->write_seq, val);
 		else if (tp->repair_queue == TCP_RECV_QUEUE)
-			tp->rcv_nxt = val;
+			WRITE_ONCE(tp->rcv_nxt, val);
 		else
 			err = -EINVAL;
 		break;
@@ -3831,7 +3840,13 @@ EXPORT_SYMBOL(tcp_md5_hash_key);
 
 void tcp_done(struct sock *sk)
 {
-	struct request_sock *req = tcp_sk(sk)->fastopen_rsk;
+	struct request_sock *req;
+
+	/* We might be called with a new socket, after
+	 * inet_csk_prepare_forced_close() has been called
+	 * so we can not use lockdep_sock_is_held(sk)
+	 */
+	req = rcu_dereference_protected(tcp_sk(sk)->fastopen_rsk, 1);
 
 	if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV)
 		TCP_INC_STATS(sock_net(sk), TCP_MIB_ATTEMPTFAILS);