net: only invoke dev->change_rx_flags when device is UP (b6c40d68) · Commits · 戴 / test

Jesper Dangaard Brouer <hawk@comx.dk> reported a bug when setting a VLAN device down that is in promiscous mode: When the VLAN device is set down, the promiscous count on the real device is decremented by one by vlan_dev_stop(). When removing the promiscous flag from the VLAN device afterwards, the promiscous count on the real device is decremented a second time by the vlan_change_rx_flags() callback. The root cause for this is that the ->change_rx_flags() callback is invoked while the device is down. The synchronization is meant to mirror the behaviour of the ->set_rx_mode callbacks, meaning the ->open function is responsible for doing a full sync on open, the ->close() function is responsible for doing full cleanup on ->stop() and ->change_rx_flags() is meant to do incremental changes while the device is UP. Only invoke ->change_rx_flags() while the device is UP to provide the intended behaviour. Tested-by:

Jesper Dangaard Brouer <jdb@comx.dk> Signed-off-by:

Patrick McHardy <kaber@trash.net> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/core/dev.c

+10 −6

Original line number	Diff line number	Diff line
		@@ -2918,6 +2918,12 @@ int netdev_set_master(struct net_device slave, struct net_device master)
		return 0;
		}

		static void dev_change_rx_flags(struct net_device *dev, int flags)
		{
		if (dev->flags & IFF_UP && dev->change_rx_flags)
		dev->change_rx_flags(dev, flags);
		}

		static int __dev_set_promiscuity(struct net_device *dev, int inc)
		{
		unsigned short old_flags = dev->flags;
		@@ -2955,8 +2961,7 @@ static int __dev_set_promiscuity(struct net_device *dev, int inc)
		current->uid, current->gid,
		audit_get_sessionid(current));

		if (dev->change_rx_flags)
		dev->change_rx_flags(dev, IFF_PROMISC);
		dev_change_rx_flags(dev, IFF_PROMISC);
		}
		return 0;
		}
		@@ -3022,8 +3027,7 @@ int dev_set_allmulti(struct net_device *dev, int inc)
		}
		}
		if (dev->flags ^ old_flags) {
		if (dev->change_rx_flags)
		dev->change_rx_flags(dev, IFF_ALLMULTI);
		dev_change_rx_flags(dev, IFF_ALLMULTI);
		dev_set_rx_mode(dev);
		}
		return 0;
		@@ -3347,8 +3351,8 @@ int dev_change_flags(struct net_device *dev, unsigned flags)
		* Load in the correct multicast list now the flags have changed.
		*/

		if (dev->change_rx_flags && (old_flags ^ flags) & IFF_MULTICAST)
		dev->change_rx_flags(dev, IFF_MULTICAST);
		if ((old_flags ^ flags) & IFF_MULTICAST)
		dev_change_rx_flags(dev, IFF_MULTICAST);

		dev_set_rx_mode(dev);

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