[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: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h
index 61a57dc..7f71df4 100644
--- a/include/linux/if_vlan.h
+++ b/include/linux/if_vlan.h
@@ -132,8 +132,6 @@
* 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 */
diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c
index abb9900..39bdcc2 100644
--- a/net/8021q/vlan.c
+++ b/net/8021q/vlan.c
@@ -373,6 +373,7 @@
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;
diff --git a/net/8021q/vlan.h b/net/8021q/vlan.h
index 62ce1c5..7df5b29 100644
--- a/net/8021q/vlan.h
+++ b/net/8021q/vlan.h
@@ -69,6 +69,7 @@
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);
diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c
index d4a62d1..dec7e62 100644
--- a/net/8021q/vlan_dev.c
+++ b/net/8021q/vlan_dev.c
@@ -712,6 +712,11 @@
}
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 @@
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 @@
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)) {