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Commit 6c78dcbd authored by Patrick McHardy's avatar Patrick McHardy Committed by David S. Miller
Browse files

[VLAN]: Fix promiscous/allmulti synchronization races 



The set_multicast_list function may be called without holding the rtnl
mutex, resulting in races when changing the underlying device's promiscous
and allmulti state. Use the change_rx_mode hook, which is always invoked
under the rtnl.

Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a0a400d7

include/linux/if_vlan.h

+0 −2
Original line number Diff line number Diff line
@@ -132,8 +132,6 @@ struct vlan_dev_info { 
                                           * made, in order to feed the right changes down

                                           * to the real hardware...

                                           */

	int old_allmulti;               /* similar to above. */

	int old_promiscuity;            /* similar to above. */

	struct net_device *real_dev;    /* the underlying device/interface */

	unsigned char real_dev_addr[ETH_ALEN];

	struct proc_dir_entry *dent;    /* Holds the proc data */

net/8021q/vlan.c

+1 −0
Original line number Diff line number Diff line
@@ -373,6 +373,7 @@ void vlan_setup(struct net_device *new_dev) 
	new_dev->open = vlan_dev_open;

	new_dev->stop = vlan_dev_stop;

	new_dev->set_multicast_list = vlan_dev_set_multicast_list;

	new_dev->change_rx_flags = vlan_change_rx_flags;

	new_dev->destructor = free_netdev;

	new_dev->do_ioctl = vlan_dev_ioctl;

net/8021q/vlan.h

+1 −0
Original line number Diff line number Diff line
@@ -69,6 +69,7 @@ int vlan_dev_set_vlan_flag(const struct net_device *dev, 
			   u32 flag, short flag_val);

void vlan_dev_get_realdev_name(const struct net_device *dev, char *result);

void vlan_dev_get_vid(const struct net_device *dev, unsigned short *result);

void vlan_change_rx_flags(struct net_device *dev, int change);

void vlan_dev_set_multicast_list(struct net_device *vlan_dev);



int vlan_check_real_dev(struct net_device *real_dev, unsigned short vlan_id);

net/8021q/vlan_dev.c

+20 −18
Original line number Diff line number Diff line
@@ -712,6 +712,11 @@ int vlan_dev_open(struct net_device *dev) 
	}

	memcpy(vlan->real_dev_addr, real_dev->dev_addr, ETH_ALEN);



	if (dev->flags & IFF_ALLMULTI)

		dev_set_allmulti(real_dev, 1);

	if (dev->flags & IFF_PROMISC)

		dev_set_promiscuity(real_dev, 1);



	return 0;

}
@@ -721,6 +726,11 @@ int vlan_dev_stop(struct net_device *dev) 


	vlan_flush_mc_list(dev);



	if (dev->flags & IFF_ALLMULTI)

		dev_set_allmulti(real_dev, -1);

	if (dev->flags & IFF_PROMISC)

		dev_set_promiscuity(real_dev, -1);



	if (compare_ether_addr(dev->dev_addr, real_dev->dev_addr))

		dev_unicast_delete(real_dev, dev->dev_addr, dev->addr_len);
@@ -754,34 +764,26 @@ int vlan_dev_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 
	return err;

}



void vlan_change_rx_flags(struct net_device *dev, int change)

{

	struct net_device *real_dev = VLAN_DEV_INFO(dev)->real_dev;



	if (change & IFF_ALLMULTI)

		dev_set_allmulti(real_dev, dev->flags & IFF_ALLMULTI ? 1 : -1);

	if (change & IFF_PROMISC)

		dev_set_promiscuity(real_dev, dev->flags & IFF_PROMISC ? 1 : -1);

}



/** Taken from Gleb + Lennert's VLAN code, and modified... */

void vlan_dev_set_multicast_list(struct net_device *vlan_dev)

{

	struct dev_mc_list *dmi;

	struct net_device *real_dev;

	int inc;



	if (vlan_dev && (vlan_dev->priv_flags & IFF_802_1Q_VLAN)) {

		/* Then it's a real vlan device, as far as we can tell.. */

		real_dev = VLAN_DEV_INFO(vlan_dev)->real_dev;



		/* compare the current promiscuity to the last promisc we had.. */

		inc = vlan_dev->promiscuity - VLAN_DEV_INFO(vlan_dev)->old_promiscuity;

		if (inc) {

			printk(KERN_INFO "%s: dev_set_promiscuity(master, %d)\n",

			       vlan_dev->name, inc);

			dev_set_promiscuity(real_dev, inc); /* found in dev.c */

			VLAN_DEV_INFO(vlan_dev)->old_promiscuity = vlan_dev->promiscuity;

		}



		inc = vlan_dev->allmulti - VLAN_DEV_INFO(vlan_dev)->old_allmulti;

		if (inc) {

			printk(KERN_INFO "%s: dev_set_allmulti(master, %d)\n",

			       vlan_dev->name, inc);

			dev_set_allmulti(real_dev, inc); /* dev.c */

			VLAN_DEV_INFO(vlan_dev)->old_allmulti = vlan_dev->allmulti;

		}



		/* looking for addresses to add to master's list */

		for (dmi = vlan_dev->mc_list; dmi != NULL; dmi = dmi->next) {

			if (vlan_should_add_mc(dmi, VLAN_DEV_INFO(vlan_dev)->old_mc_list)) {