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From: David Marchand <david.marchand@pace.com>
To: netdev@vger.kernel.org
Subject: [RFC] Move in6_dev_hold under CONFIG_IPV6_PRIVACY
Date: Thu, 30 Aug 2012 11:42:33 +0200	[thread overview]
Message-ID: <503F3589.5070804@pace.com> (raw)

Hello,

I am currently looking at a problem with in6 interface refcnt on a 
really old kernel and I have just noticed something I find suspicious in 
all kernels until now.

The comment at net/ipv6/addrconf.c:396 suggests that the call to 
in6_dev_hold is only for ipv6_regen_rndid.
As a consequence, if CONFIG_IPV6_PRIVACY is not set, then this 
in6_dev_hold will leak a refcnt.

Can someone look at this ?
I did not test this patch, yet it looks reasonable to me.

Thank you.


$ git diff
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 6bc85f7..263fcf3 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -393,11 +393,6 @@ static struct inet6_dev *ipv6_add_dev(struct 
net_device *dev)
                 return NULL;
         }

-       /* One reference from device.  We must do this before
-        * we invoke __ipv6_regen_rndid().
-        */
-       in6_dev_hold(ndev);
-
         if (dev->flags & (IFF_NOARP | IFF_LOOPBACK))
                 ndev->cnf.accept_dad = -1;

@@ -410,6 +405,12 @@ static struct inet6_dev *ipv6_add_dev(struct 
net_device *dev)

  #ifdef CONFIG_IPV6_PRIVACY
         INIT_LIST_HEAD(&ndev->tempaddr_list);
+
+       /* One reference from device.  We must do this before
+        * we invoke ipv6_regen_rndid().
+        */
+       in6_dev_hold(ndev);
+
         setup_timer(&ndev->regen_timer, ipv6_regen_rndid, (unsigned 
long)ndev);
         if ((dev->flags&IFF_LOOPBACK) ||
             dev->type == ARPHRD_TUNNEL ||



-- 
David Marchand


This message has been scanned for viruses by BlackSpider MailControl. - www.blackspider.com

             reply	other threads:[~2012-08-30 10:32 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-08-30  9:42 David Marchand [this message]
2012-08-30 15:25 ` [RFC] Move in6_dev_hold under CONFIG_IPV6_PRIVACY Eric Dumazet
2012-08-30 16:52   ` David Marchand
2012-08-30 17:28     ` Eric Dumazet

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