[ovs-git] [openvswitch/ovs] 38008c: ip_tunnel: Fix bugs that could crash kernel

[GitHub]

  Branch: refs/heads/branch-2.10
  Home:   https://github.com/openvswitch/ovs
  Commit: 38008c4bc5104f73f2300a1645f9087ff358af42
      https://github.com/openvswitch/ovs/commit/38008c4bc5104f73f2300a1645f9087ff358af42
  Author: Yifeng Sun <pkusunyifeng at gmail.com>
  Date:   2018-08-15 (Wed, 15 Aug 2018)

  Changed paths:
    M datapath/linux/compat/ip_tunnel.c

  Log Message:
  -----------
  ip_tunnel: Fix bugs that could crash kernel

Without this patch, OVS kernel module can delete itn->fb_tunnel_dev
one more time than necessary, which causes kernel crash.

On kernel 4.4.0-116-generic, the crash can be reproduced by running
the simple test provided below through check-kernel.

  make & make modules_install
  rmmod ip_gre gre ip_tunnel
  modprobe openvswitch
  make check-kernel TESTSUITEFLAGS=x
  dmesg

Simple test:

AT_SETUP([datapath - crash test])
OVS_CHECK_GRE()
ip link del gre0
OVS_TRAFFIC_VSWITCHD_START()
AT_CHECK([ovs-vsctl -- set bridge br0])
ADD_BR([br-underlay], [set bridge br-underlay])
AT_CHECK([ovs-ofctl add-flow br0 "actions=normal"])
AT_CHECK([ovs-ofctl add-flow br-underlay "actions=normal"])
ADD_NAMESPACES(at_ns0)
ADD_VETH(p0, at_ns0, br-underlay, "172.31.1.1/24")
AT_CHECK([ip addr add dev br-underlay "172.31.1.100/24"])
AT_CHECK([ip link set dev br-underlay up])
ADD_OVS_TUNNEL([gre], [br0], [at_gre0], [172.31.1.1], [10.1.1.100/24])
tcpdump -U -i br-underlay -w underlay.pcap &
sleep 1
OVS_TRAFFIC_VSWITCHD_STOP
AT_CLEANUP

Signed-off-by: Yifeng Sun <pkusunyifeng at gmail.com>
Signed-off-by: Ben Pfaff <blp at ovn.org>
Acked-by: William Tu <u9012063 at gmail.com>



      **NOTE:** This service has been marked for deprecation: https://developer.github.com/changes/2018-04-25-github-services-deprecation/

      Functionality will be removed from GitHub.com on January 31st, 2019.