Re: [PATCH] net: ipv6: Remove addresses for failures with strict DAD

On Wed, Aug 17, 2016, at 18:08, Mike Manning wrote:

On 08/17/2016 04:40 PM, Hannes Frederic Sowa wrote:

quoted

On 17.08.2016 12:28, Mike Manning wrote:

quoted

+static void dev_disable_change(struct inet6_dev *idev);
 
 /*
  *	Configured unicast address hash table

@@ -1945,6 +1946,12 @@ lock_errdad:
 
 			pr_info("%s: IPv6 being disabled!\n",
 				ifp->idev->dev->name);
+			spin_unlock_bh(&ifp->lock);
+			addrconf_dad_stop(ifp, 1);
+			rtnl_lock();
+			dev_disable_change(idev);
+			rtnl_unlock();
+			return;
 		}
 	}

You can't take rtnl_lock at that point but must postpone the actions and
do that in addrconf_dad_work.

Probably the whole ... else if (idev->cnf.accept_dad > 1 && ...) needs
to move there.

Bye,
Hannes

Thanks for the prompt review, I will look into making these changes.

Also these changes caused a build error due to conditional compilation
without CONFIG_SYSCTL, which is resolved by replacing the call to
dev_disable_change(idev) by directly calling addrconf_ifdown(idev->dev,
0) instead.

I would appreciate any further comments if the suggested change in
behavior is not acceptable.

What you describe in the changelog what is happening right now looks
like a bug to me thus your patch made sense to me.

Bye,
Hannes