From 2fe97a578d7bad3116a89dc8a6692a51e6fc1d9c Mon Sep 17 00:00:00 2001
From: Tung Nguyen <tung.q.nguyen@dektech.com.au>
Date: Thu, 28 Nov 2019 10:10:05 +0700
Subject: [PATCH] tipc: fix potential memory leak in __tipc_sendmsg()
Git-commit: 2fe97a578d7bad3116a89dc8a6692a51e6fc1d9c
Patch-mainline: v5.5-rc1
References: git-fixes

When initiating a connection message to a server side, the connection
message is cloned and added to the socket write queue. However, if the
cloning is failed, only the socket write queue is purged. It causes
memory leak because the original connection message is not freed.

This commit fixes it by purging the list of connection message when
it cannot be cloned.

Fixes: 6787927475e5 ("tipc: buffer overflow handling in listener socket")
Reported-by: Hoang Le <hoang.h.le@dektech.com.au>
Signed-off-by: Tung Nguyen <tung.q.nguyen@dektech.com.au>
Acked-by: Ying Xue <ying.xue@windriver.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 net/tipc/socket.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index a1c8d722ca20..7baed2c2c93d 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -1447,8 +1447,10 @@ static int __tipc_sendmsg(struct socket *sock, struct msghdr *m, size_t dlen)
 	rc = tipc_msg_build(hdr, m, 0, dlen, mtu, &pkts);
 	if (unlikely(rc != dlen))
 		return rc;
-	if (unlikely(syn && !tipc_msg_skb_clone(&pkts, &sk->sk_write_queue)))
+	if (unlikely(syn && !tipc_msg_skb_clone(&pkts, &sk->sk_write_queue))) {
+		__skb_queue_purge(&pkts);
 		return -ENOMEM;
+	}
 
 	trace_tipc_sk_sendmsg(sk, skb_peek(&pkts), TIPC_DUMP_SK_SNDQ, " ");
 	rc = tipc_node_xmit(net, &pkts, dnode, tsk->portid);
-- 
2.16.4