Commit 9f514950 authored Mar 25, 2006 by Herbert Xu Committed by David S. Miller Mar 25, 2006

[NET]: Take RTNL when unregistering notifier

The netdev notifier call chain is currently unregistered without taking
any locks outside the notifier system. Because the notifier system itself
does not synchronise unregistration with respect to the calling of the
chain, we as its user need to do our own locking.

We are supposed to take the RTNL for all calls to netdev notifiers, so
taking the RTNL should be sufficient to protect it.

The registration path in dev.c already takes the RTNL so it's OK.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 868d2c1e

net/core/dev.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -977,7 +977,12 @@ int register_netdevice_notifier(struct notifier_block *nb)

		int unregister_netdevice_notifier(struct notifier_block *nb)
		{
		return notifier_chain_unregister(&netdev_chain, nb);
		int err;

		rtnl_lock();
		err = notifier_chain_unregister(&netdev_chain, nb);
		rtnl_unlock();
		return err;
		}

		/**

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