From patchwork Thu Dec 13 13:59:27 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [202/241] tcp-repair: Handle zero-length data put in rcv queue Date: Thu, 13 Dec 2012 03:59:27 -0000 From: Herton Ronaldo Krzesinski X-Patchwork-Id: 206048 Message-Id: <1355407206-17100-203-git-send-email-herton.krzesinski@canonical.com> To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: "David S. Miller" , Pavel Emelyanov 3.5.7.2 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Pavel Emelyanov 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 Reported-by: Giorgos Mavrikas Signed-off-by: David S. Miller [ herton: unfuzz patch for 3.5, place size check before tcp_try_rmem_schedule ] Signed-off-by: Herton Ronaldo Krzesinski --- 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;