[ovs-dev] [PATCH] ip_tunnel: Fix bugs that could crash kernel

[Ben Pfaff]

On Fri, Jul 20, 2018 at 04:13:14PM -0700, William Tu wrote:
> On Fri, Jul 20, 2018 at 11:04 AM, Yifeng Sun <pkusunyifeng at gmail.com> wrote:
> > 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>
> > ---
> 
> LGTM, Thanks for the fix.
> Acked-by: William Tu <u9012063 at gmail.com>

Thanks Yifeng (and William).

I applied this to master and branch-2.10.  If it should be backported
farther, please let me know.