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

Pull networking fixes from David Miller:

 1) Revert iwlwifi reclaimed packet tracking, it causes problems for a
    bunch of folks.  From Emmanuel Grumbach.

 2) Work limiting code in brcmsmac wifi driver can clear tx status
    without processing the event.  From Arend van Spriel.

 3) rtlwifi USB driver processes wrong SKB, fix from Larry Finger.

 4) l2tp tunnel delete can race with close, fix from Tom Parkin.

 5) pktgen_add_device() failures are not checked at all, fix from Cong
    Wang.

 6) Fix unintentional removal of carrier off from tun_detach(),
    otherwise we confuse userspace, from Michael S.  Tsirkin.

 7) Don't leak socket reference counts and ubufs in vhost-net driver,
    from Jason Wang.

 8) vmxnet3 driver gets it's initial carrier state wrong, fix from Neil
    Horman.

 9) Protect against USB networking devices which spam the host with 0
    length frames, from Bjørn Mork.

10) Prevent neighbour overflows in ipv6 for locally destined routes,
    from Marcelo Ricardo.  This is the best short-term fix for this, a
    longer term fix has been implemented in net-next.

11) L2TP uses ipv4 datagram routines in it's ipv6 code, whoops.  This
    mistake is largely because the ipv6 functions don't even have some
    kind of prefix in their names to suggest they are ipv6 specific.
    From Tom Parkin.

12) Check SYN packet drops properly in tcp_rcv_fastopen_synack(), from
    Yuchung Cheng.

13) Fix races and TX skb freeing bugs in via-rhine's NAPI support, from
    Francois Romieu and your's truly.

14) Fix infinite loops and divides by zero in TCP congestion window
    handling, from Eric Dumazet, Neal Cardwell, and Ilpo Järvinen.

15) AF_PACKET tx ring handling can leak kernel memory to userspace, fix
    from Phil Sutter.

16) Fix error handling in ipv6 GRE tunnel transmit, from Tommi Rantala.

17) Protect XEN netback driver against hostile frontend putting garbage
    into the rings, don't leak pages in TX GOP checking, and add proper
    resource releasing in error path of xen_netbk_get_requests().  From
    Ian Campbell.

18) SCTP authentication keys should be cleared out and released with
    kzfree(), from Daniel Borkmann.

19) L2TP is a bit too clever trying to maintain skb->truesize, and ends
    up corrupting socket memory accounting to the point where packet
    sending is halted indefinitely.  Just remove the adjustments
    entirely, they aren't really needed.  From Eric Dumazet.

20) ATM Iphase driver uses a data type with the same name as the S390
    headers, rename to fix the build.  From Heiko Carstens.

21) Fix a typo in copying the inner network header offset from one SKB
    to another, from Pravin B Shelar.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (56 commits)
  net: sctp: sctp_endpoint_free: zero out secret key data
  net: sctp: sctp_setsockopt_auth_key: use kzfree instead of kfree
  atm/iphase: rename fregt_t -> ffreg_t
  net: usb: fix regression from FLAG_NOARP code
  l2tp: dont play with skb->truesize
  net: sctp: sctp_auth_key_put: use kzfree instead of kfree
  netback: correct netbk_tx_err to handle wrap around.
  xen/netback: free already allocated memory on failure in xen_netbk_get_requests
  xen/netback: don't leak pages on failure in xen_netbk_tx_check_gop.
  xen/netback: shutdown the ring if it contains garbage.
  net: qmi_wwan: add more Huawei devices, including E320
  net: cdc_ncm: add another Huawei vendor specific device
  ipv6/ip6_gre: fix error case handling in ip6gre_tunnel_xmit()
  tcp: fix for zero packets_in_flight was too broad
  brcmsmac: rework of mac80211 .flush() callback operation
  ssb: unregister gpios before unloading ssb
  bcma: unregister gpios before unloading bcma
  rtlwifi: Fix scheduling while atomic bug
  net: usbnet: fix tx_dropped statistics
  tcp: ipv6: Update MIB counters for drops
  ...

1 files changed, 65 insertions, 17 deletions

diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c
index 1a9f3723c13..2ac884d0e89 100644
--- a/net/l2tp/l2tp_core.c
+++ b/net/l2tp/l2tp_core.c
@@ -168,6 +168,51 @@ l2tp_session_id_hash_2(struct l2tp_net *pn, u32 session_id)
 
 }
 
+/* Lookup the tunnel socket, possibly involving the fs code if the socket is
+ * owned by userspace.  A struct sock returned from this function must be
+ * released using l2tp_tunnel_sock_put once you're done with it.
+ */
+struct sock *l2tp_tunnel_sock_lookup(struct l2tp_tunnel *tunnel)
+{
+	int err = 0;
+	struct socket *sock = NULL;
+	struct sock *sk = NULL;
+
+	if (!tunnel)
+		goto out;
+
+	if (tunnel->fd >= 0) {
+		/* Socket is owned by userspace, who might be in the process
+		 * of closing it.  Look the socket up using the fd to ensure
+		 * consistency.
+		 */
+		sock = sockfd_lookup(tunnel->fd, &err);
+		if (sock)
+			sk = sock->sk;
+	} else {
+		/* Socket is owned by kernelspace */
+		sk = tunnel->sock;
+	}
+
+out:
+	return sk;
+}
+EXPORT_SYMBOL_GPL(l2tp_tunnel_sock_lookup);
+
+/* Drop a reference to a tunnel socket obtained via. l2tp_tunnel_sock_put */
+void l2tp_tunnel_sock_put(struct sock *sk)
+{
+	struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk);
+	if (tunnel) {
+		if (tunnel->fd >= 0) {
+			/* Socket is owned by userspace */
+			sockfd_put(sk->sk_socket);
+		}
+		sock_put(sk);
+	}
+}
+EXPORT_SYMBOL_GPL(l2tp_tunnel_sock_put);
+
 /* Lookup a session by id in the global session list
  */
 static struct l2tp_session *l2tp_session_find_2(struct net *net, u32 session_id)
@@ -1123,8 +1168,6 @@ int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len
 	struct udphdr *uh;
 	struct inet_sock *inet;
 	__wsum csum;
-	int old_headroom;
-	int new_headroom;
 	int headroom;
 	int uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0;
 	int udp_len;
@@ -1136,16 +1179,12 @@ int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len
 	 */
 	headroom = NET_SKB_PAD + sizeof(struct iphdr) +
 		uhlen + hdr_len;
-	old_headroom = skb_headroom(skb);
 	if (skb_cow_head(skb, headroom)) {
 		kfree_skb(skb);
 		return NET_XMIT_DROP;
 	}
 
-	new_headroom = skb_headroom(skb);
 	skb_orphan(skb);
-	skb->truesize += new_headroom - old_headroom;
-
 	/* Setup L2TP header */
 	session->build_header(session, __skb_push(skb, hdr_len));
 
@@ -1607,6 +1646,7 @@ int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, u32
 	tunnel->old_sk_destruct = sk->sk_destruct;
 	sk->sk_destruct = &l2tp_tunnel_destruct;
 	tunnel->sock = sk;
+	tunnel->fd = fd;
 	lockdep_set_class_and_name(&sk->sk_lock.slock, &l2tp_socket_class, "l2tp_sock");
 
 	sk->sk_allocation = GFP_ATOMIC;
@@ -1642,24 +1682,32 @@ EXPORT_SYMBOL_GPL(l2tp_tunnel_create);
  */
 int l2tp_tunnel_delete(struct l2tp_tunnel *tunnel)
 {
-	int err = 0;
-	struct socket *sock = tunnel->sock ? tunnel->sock->sk_socket : NULL;
+	int err = -EBADF;
+	struct socket *sock = NULL;
+	struct sock *sk = NULL;
+
+	sk = l2tp_tunnel_sock_lookup(tunnel);
+	if (!sk)
+		goto out;
+
+	sock = sk->sk_socket;
+	BUG_ON(!sock);
 
 	/* Force the tunnel socket to close. This will eventually
 	 * cause the tunnel to be deleted via the normal socket close
 	 * mechanisms when userspace closes the tunnel socket.
 	 */
-	if (sock != NULL) {
-		err = inet_shutdown(sock, 2);
+	err = inet_shutdown(sock, 2);
 
-		/* If the tunnel's socket was created by the kernel,
-		 * close the socket here since the socket was not
-		 * created by userspace.
-		 */
-		if (sock->file == NULL)
-			err = inet_release(sock);
-	}
+	/* If the tunnel's socket was created by the kernel,
+	 * close the socket here since the socket was not
+	 * created by userspace.
+	 */
+	if (sock->file == NULL)
+		err = inet_release(sock);
 
+	l2tp_tunnel_sock_put(sk);
+out:
 	return err;
 }
 EXPORT_SYMBOL_GPL(l2tp_tunnel_delete);