[37/71] net: dev_close() should check IFF_UP

From: Greg KH
Date: Thu May 19 2011 - 14:08:50 EST

2.6.38-stable review patch. If anyone has any objections, please let us know.


From: Eric Dumazet <eric.dumazet@xxxxxxxxx>

commit e14a599335427f81bbb0008963e59aa9c6449dce upstream.

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@xxxxxxxxxxxxxxxxxx>
Reported-by: Einar EL Lueck <ELELUECK@xxxxxxxxxx>
Signed-off-by: Eric Dumazet <eric.dumazet@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

net/core/dev.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1332,11 +1332,13 @@ int dev_close_many(struct list_head *hea
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;

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