[202/241] tcp-repair: Handle zero-length data put in rcv queue

Message ID 1355407206-17100-203-git-send-email-herton.krzesinski@canonical.com
State New
Headers show

Commit Message

Herton Ronaldo Krzesinski Dec. 13, 2012, 1:59 p.m. -stable review patch.  If anyone has any objections, please let me know.


From: Pavel Emelyanov <xemul@parallels.com>

commit c454e6111d1ef4268fe98e87087216e51c2718c3 upstream.

When sending data into a tcp socket in repair state we should check
for the amount of data being 0 explicitly. Otherwise we'll have an skb
with seq == end_seq in rcv queue, but tcp doesn't expect this to happen
(in particular a warn_on in tcp_recvmsg shoots).

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Reported-by: Giorgos Mavrikas <gmavrikas@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[ herton: unfuzz patch for 3.5, place size check before
  tcp_try_rmem_schedule ]
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
 net/ipv4/tcp_input.c |    3 +++
 1 file changed, 3 insertions(+)


diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index ab30c96..4a3cac8 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -4713,6 +4713,9 @@  int tcp_send_rcvq(struct sock *sk, struct msghdr *msg, size_t size)
 	struct tcphdr *th;
 	bool fragstolen;
+	if (size == 0)
+		return 0;
 	if (tcp_try_rmem_schedule(sk, size + sizeof(*th)))
 		goto err;