[Bug 1130] New: GRE tunnels freeze kernel

[Bug 1130] New: GRE tunnels freeze kernel

[Martin J. Bligh]

http://bugme.osdl.org/show_bug.cgi?id=1130

           Summary: GRE tunnels freeze kernel
    Kernel Version: 2.6.0-test2, 2.6.0-test3
            Status: NEW
          Severity: high
             Owner: bugme-janitors@lists.osdl.org
         Submitter: michal-bugzilla@logix.cz


Distribution: SuSE Linux 8.2
Hardware Environment: x86
Software Environment: gcc-3.3 used to compile kernel.

Problem Description:
Incoming packet to the GRE tunnel interface freezes the kernel.

Steps to reproduce:
On a 2.6.0-test system create a tunnel for instance with these steps:

On 10.0.0.1:
modprobe ip_gre
ip tunnel add gre1 mode gre local 10.0.0.1 remote 10.0.0.2 ttl 64
ip link set gre1 up
ip addr add 172.16.0.1/24 dev gre1

On a non-2.6.0 10.0.0.2:
modprobe ip_gre
ip tunnel add gre1 mode gre local 10.0.0.2 remote 10.0.0.1 ttl 64
ip link set gre1 up
ip addr add 172.16.0.2/24 dev gre1

Now ping the 2.6.0 system:
ping -c1 172.16.0.1

Upon receiving the packet the box foreezes. No Oops but neither <Alt>+<F>
console switching nor NumLock worked anymore. (Don't know about SysRq).