1 files changed, 27 insertions, 7 deletions

diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index 8754bd885169..e3105ba407c7 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -1886,6 +1886,7 @@ static int tipc_recvmsg(struct socket *sock, struct msghdr *m,
 	bool connected = !tipc_sk_type_connectionless(sk);
 	struct tipc_sock *tsk = tipc_sk(sk);
 	int rc, err, hlen, dlen, copy;
+	struct tipc_skb_cb *skb_cb;
 	struct sk_buff_head xmitq;
 	struct tipc_msg *hdr;
 	struct sk_buff *skb;
@@ -1909,6 +1910,7 @@ static int tipc_recvmsg(struct socket *sock, struct msghdr *m,
 		if (unlikely(rc))
 			goto exit;
 		skb = skb_peek(&sk->sk_receive_queue);
+		skb_cb = TIPC_SKB_CB(skb);
 		hdr = buf_msg(skb);
 		dlen = msg_data_sz(hdr);
 		hlen = msg_hdr_sz(hdr);
@@ -1928,18 +1930,33 @@ static int tipc_recvmsg(struct socket *sock, struct msghdr *m,
 
 	/* Capture data if non-error msg, otherwise just set return value */
 	if (likely(!err)) {
-		copy = min_t(int, dlen, buflen);
-		if (unlikely(copy != dlen))
-			m->msg_flags |= MSG_TRUNC;
-		rc = skb_copy_datagram_msg(skb, hlen, m, copy);
+		int offset = skb_cb->bytes_read;
+
+		copy = min_t(int, dlen - offset, buflen);
+		rc = skb_copy_datagram_msg(skb, hlen + offset, m, copy);
+		if (unlikely(rc))
+			goto exit;
+		if (unlikely(offset + copy < dlen)) {
+			if (flags & MSG_EOR) {
+				if (!(flags & MSG_PEEK))
+					skb_cb->bytes_read = offset + copy;
+			} else {
+				m->msg_flags |= MSG_TRUNC;
+				skb_cb->bytes_read = 0;
+			}
+		} else {
+			if (flags & MSG_EOR)
+				m->msg_flags |= MSG_EOR;
+			skb_cb->bytes_read = 0;
+		}
 	} else {
 		copy = 0;
 		rc = 0;
-		if (err != TIPC_CONN_SHUTDOWN && connected && !m->msg_control)
+		if (err != TIPC_CONN_SHUTDOWN && connected && !m->msg_control) {
 			rc = -ECONNRESET;
+			goto exit;
+		}
 	}
-	if (unlikely(rc))
-		goto exit;
 
 	/* Mark message as group event if applicable */
 	if (unlikely(grp_evt)) {
@@ -1962,6 +1979,9 @@ static int tipc_recvmsg(struct socket *sock, struct msghdr *m,
 		tipc_node_distr_xmit(sock_net(sk), &xmitq);
 	}
 
+	if (skb_cb->bytes_read)
+		goto exit;
+
 	tsk_advance_rx_queue(sk);
 
 	if (likely(!connected))