Dear all,
a regression has been introduced in Linux Kernels by patch https://github.com/torvalds/linux/commit/efe4208f47f907
The regression behaves in a way that when there are multiple IPv6 sockets created with multicast/link-local addresses on the same interface, handling of the packets is broken. (Reported e. g. on http://www.spinics.net/lists/netdev/msg286344.html)
This can be reproduced by
1. installing Ubuntu 14.04 with default kernel
2. installing dibbler-server and configuring with basic dhcpv6 settings (hand out one subnet), for example:
/etc/dibbler/server.conf:
log-level 8
preference 0
iface <IFACE> {
t1 1800-2000
t2 2700-3000
prefered-lifetime 3600
valid-lifetime 7200
subnet 2001:db8:abcd::/64
class {
pool 2001:db8:abcd::1000-2001:db8:abcd::1fff
}
ta-class {
pool 2001:db8:abcd::2000-2001:db8:abcd::2fff
}
option dns-server 2001:db8:abcd::1
}
3. get a DHCPv6 client and request addresses from the server
4. view the packets on the interface affected, use e.g.: tcpdump -i <IFACE> '(udp port 546)||(udp port 547)' -n
There will be multicast DHCPv6 solicits, however no DHCPv6 responses, as Dibbler creates two sockets on the same interface (multicast socket first, link-local socket next).
There is a patch available in the upstream, that will be probably merged to 3.15.2 kernel (it is not present in current 3.15.1 vanilla kernel) - http://patchwork.ozlabs.org/patch/352246/
When applying this patch to trusty-proposed linux-image-3.13.0-30-generic_3.13.0-30.54 from Git repositories at git clone git://kernel.ubuntu.com/ubuntu/ubuntu-trusty.git and recompiling the kernel, everything starts to work as expected.
Please apply this patch ASAP to fix IPv6 multicast, there is more and more IPv6 in the wild and this bug is a serious one.
---
ApportVersion: 2.14.1-0ubuntu3.2
Architecture: amd64
AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1:
DistroRelease: Ubuntu 14.04
InstallationDate: Installed on 2012-04-24 (786 days ago)
InstallationMedia: Ubuntu-Server 12.04 LTS "Precise Pangolin" - Beta amd64 (20120327)
MachineType: Gigabyte Technology Co., Ltd. To be filled by O.E.M.
Package: linux (not installed)
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-30-generic root=/dev/md1 ro nosplash nosplash nomdmonddf nomdmonisw
ProcVersionSignature: Ubuntu 3.13.0-30.54-generic 3.13.11.2
PulseList: Error: command ['pacmd', 'list'] failed with exit code 1: No PulseAudio daemon running, or not running as session daemon.
RelatedPackageVersions:
linux-restricted-modules-3.13.0-30-generic N/A
linux-backports-modules-3.13.0-30-generic N/A
linux-firmware 1.127.2
RfKill:
0: hci0: Bluetooth
Soft blocked: no
Hard blocked: no
Tags: trusty
Uname: Linux 3.13.0-30-generic x86_64
UpgradeStatus: Upgraded to trusty on 2014-04-24 (56 days ago)
UserGroups:
_MarkForUpload: True
dmi.bios.date: 08/23/2012
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: F2
dmi.board.asset.tag: To be filled by O.E.M.
dmi.board.name: H77N-WIFI
dmi.board.vendor: Gigabyte Technology Co., Ltd.
dmi.board.version: x.x
dmi.chassis.asset.tag: To Be Filled By O.E.M.
dmi.chassis.type: 3
dmi.chassis.vendor: Gigabyte Technology Co., Ltd.
dmi.chassis.version: To Be Filled By O.E.M.
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrF2:bd08/23/2012:svnGigabyteTechnologyCo.,Ltd.:pnTobefilledbyO.E.M.:pvrTobefilledbyO.E.M.:rvnGigabyteTechnologyCo.,Ltd.:rnH77N-WIFI:rvrx.x:cvnGigabyteTechnologyCo.,Ltd.:ct3:cvrToBeFilledByO.E.M.:
dmi.product.name: To be filled by O.E.M.
dmi.product.version: To be filled by O.E.M.
dmi.sys.vendor: Gigabyte Technology Co., Ltd.
This bug is missing log files that will aid in diagnosing the problem. From a terminal window please run:
apport-collect 1332420
and then change the status of the bug to 'Confirmed'.
If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.
This change has been made by an automated script, maintained by the Ubuntu Kernel Team.