Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

Pull networking fixes from David Miller:

 1) The per-network-namespace loopback device, and thus its namespace,
    can have its teardown deferred for a long time if a kernel created
    TCP socket closes and the namespace is exiting meanwhile. The kernel
    keeps trying to finish the close sequence until it times out (which
    takes quite some time).

    Fix this by forcing the socket closed in this situation, from Dan
    Streetman.

 2) Fix regression where we're trying to invoke the update_pmtu method
    on route types (in this case metadata tunnel routes) that don't
    implement the dst_ops method. Fix from Nicolas Dichtel.

 3) Fix long standing memory corruption issues in r8169 driver by
    performing the chip statistics DMA programming more correctly. From
    Francois Romieu.

 4) Handle local broadcast sends over VRF routes properly, from David
    Ahern.

 5) Don't refire the DCCP CCID2 timer endlessly, otherwise the socket
    can never be released. From Alexey Kodanev.

 6) Set poll flags properly in VSOCK protocol layer, from Stefan
    Hajnoczi.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  VSOCK: set POLLOUT | POLLWRNORM for TCP_CLOSING
  dccp: don't restart ccid2_hc_tx_rto_expire() if sk in closed state
  net: vrf: Add support for sends to local broadcast address
  r8169: fix memory corruption on retrieval of hardware statistics.
  net: don't call update_pmtu unconditionally
  net: tcp: close sock if net namespace is exiting

1 files changed, 15 insertions, 0 deletions

diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
index 968fda198376..388158c9d9f6 100644
--- a/net/ipv4/tcp_timer.c
+++ b/net/ipv4/tcp_timer.c
@@ -48,11 +48,19 @@ static void tcp_write_err(struct sock *sk)
  *  to prevent DoS attacks. It is called when a retransmission timeout
  *  or zero probe timeout occurs on orphaned socket.
  *
+ *  Also close if our net namespace is exiting; in that case there is no
+ *  hope of ever communicating again since all netns interfaces are already
+ *  down (or about to be down), and we need to release our dst references,
+ *  which have been moved to the netns loopback interface, so the namespace
+ *  can finish exiting.  This condition is only possible if we are a kernel
+ *  socket, as those do not hold references to the namespace.
+ *
  *  Criteria is still not confirmed experimentally and may change.
  *  We kill the socket, if:
  *  1. If number of orphaned sockets exceeds an administratively configured
  *     limit.
  *  2. If we have strong memory pressure.
+ *  3. If our net namespace is exiting.
  */
 static int tcp_out_of_resources(struct sock *sk, bool do_reset)
 {
@@ -81,6 +89,13 @@ static int tcp_out_of_resources(struct sock *sk, bool do_reset)
 		__NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONMEMORY);
 		return 1;
 	}
+
+	if (!check_net(sock_net(sk))) {
+		/* Not possible to send reset; just close */
+		tcp_done(sk);
+		return 1;
+	}
+
 	return 0;
 }