This bug is missing log files that will aid in diagnosing the problem.
>From a terminal window please run:

apport-collect 1634545

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.

** Changed in: linux (Ubuntu)
       Status: New => Incomplete

You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.

  ipv6: connected routes are missing after a down/up cycle on the

Status in linux package in Ubuntu:

Bug description:
  This upstream patch is missing:

  ipv6: correctly add local routes when lo goes up

  The goal of the patch is to fix this scenario:
   ip link add dummy1 type dummy
   ip link set dummy1 up
   ip link set lo down ; ip link set lo up

  After that sequence, the local route to the link layer address of dummy1 is
  not there anymore.

  When the loopback is set down, all local routes are deleted by
  addrconf_ifdown()/rt6_ifdown(). At this time, the rt6_info entry still
  exists, because the corresponding idev has a reference on it. After the rcu
  grace period, dst_rcu_free() is called, and thus ___dst_free(), which will
  set obsolete to DST_OBSOLETE_DEAD.

  In this case, init_loopback() is called before dst_rcu_free(), thus
  obsolete is still sets to something <= 0. So, the function doesn't add the
  route again. To avoid that race, let's check the rt6 refcnt instead.

  Fixes: 25fb6ca4ed9c ("net IPv6 : Fix broken IPv6 routing table after loopback 
  Fixes: a881ae1f625c ("ipv6: don't call addrconf_dst_alloc again when enable 
  Fixes: 33d99113b110 ("ipv6: reallocate addrconf router for ipv6 address when 
lo device up")
  Reported-by: Francesco Santoro <>
  Reported-by: Samuel Gauthier <>
  CC: Balakumaran Kannan <>
  CC: Maruthi Thotad <>
  CC: Sabrina Dubroca <>
  CC: Hannes Frederic Sowa <>
  CC: Weilong Chen <>
  CC: Gao feng <>
  Signed-off-by: Nicolas Dichtel <>
  Signed-off-by: David S. Miller <>

To manage notifications about this bug go to:

Mailing list:
Post to     :
Unsubscribe :
More help   :

Reply via email to