Merge remote-tracking branch 'remotes/stefanha/tags/net-pull-request' into staging

This net pull request contains security fixes for qemu.git/master.  The patches
should also be applied to stable trees.

The ne2000 NIC model has QEMU memory corruption issue.  Both ne2000 and e1000
have an infinite loop.

Please see the patches for CVE numbers and details on the bugs.

# gpg: Signature made Tue 15 Sep 2015 13:02:21 BST using RSA key ID 81AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>"
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>"

* remotes/stefanha/tags/net-pull-request:
  net: avoid infinite loop when receiving packets(CVE-2015-5278)
  net: add checks to validate ring buffer pointers(CVE-2015-5279)
  e1000: Avoid infinite loop in processing transmit descriptor (CVE-2015-6815)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>