Re: Fw: oops during unregister_netdevice interface enslaved to bond - regression

[Eric Dumazet <eric.dumazet@gmail.com>]

Le mardi 10 mai 2011 à 15:14 +0200, Frank Blaschka a écrit :

> I just checked todays net-next tree, problem is still there.
> I don't have an x86 box, but I was able to reproduce the problem
> with the dummy device (on s/390)
> 
> # modprobe bonding
> # modprobe dummy
> # ifconfig bond0 up
> # ifenslave bond0 dummy0
> # rmmod dummy

Here is the patch to fix this problem

Thanks again for your help.

[PATCH net-2.6] net: dev_close() should check IFF_UP

Commit 443457242beb (factorize sync-rcu call in
unregister_netdevice_many) mistakenly removed one test from dev_close()

Following actions trigger a BUG :

modprobe bonding
modprobe dummy
ifconfig bond0 up
ifenslave bond0 dummy0
rmmod dummy

dev_close() must not close a non IFF_UP device.

With help from Frank Blaschka and Einar EL Lueck

Reported-by: Frank Blaschka <blaschka@linux.vnet.ibm.com>
Reported-by: Einar EL Lueck <ELELUECK@de.ibm.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Octavian Purdila <opurdila@ixiacom.com>
---
 net/core/dev.c |   10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/net/core/dev.c b/net/core/dev.c
index 856b6ee..9200944 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1284,11 +1284,13 @@ static int dev_close_many(struct list_head *head)
  */
 int dev_close(struct net_device *dev)
 {
-	LIST_HEAD(single);
+	if (dev->flags & IFF_UP) {
+		LIST_HEAD(single);
 
-	list_add(&dev->unreg_list, &single);
-	dev_close_many(&single);
-	list_del(&single);
+		list_add(&dev->unreg_list, &single);
+		dev_close_many(&single);
+		list_del(&single);
+	}
 	return 0;
 }
 EXPORT_SYMBOL(dev_close);