8021q: Check return of dev_set_promiscuity/allmulti

dev_set_promiscuity/allmulti might overflow.
Commit: "netdevice: Fix promiscuity and allmulti overflow" in net-next makes
dev_set_promiscuity/allmulti return error number if overflow happened.

Here, we check all positive increment for promiscuity and allmulti
to get error return.

Signed-off-by: Wang Chen <wangchen@cn.fujitsu.com>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 22 insertions, 6 deletions

diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c
index 8efa399823e3..9efd3c67c1db 100644
--- a/net/8021q/vlan_dev.c
+++ b/net/8021q/vlan_dev.c
@@ -518,19 +518,35 @@ static int vlan_dev_open(struct net_device *dev)
         if (compare_ether_addr(dev->dev_addr, real_dev->dev_addr)) {
                 err = dev_unicast_add(real_dev, dev->dev_addr, ETH_ALEN);
                 if (err < 0)
-                        return err;
+                        goto out;
         }
-        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);
+        if (dev->flags & IFF_ALLMULTI) {
+                err = dev_set_allmulti(real_dev, 1);
+                if (err < 0)
+                        goto del_unicast;
+        }
+        if (dev->flags & IFF_PROMISC) {
+                err = dev_set_promiscuity(real_dev, 1);
+                if (err < 0)
+                        goto clear_allmulti;
+        }
+
+        memcpy(vlan->real_dev_addr, real_dev->dev_addr, ETH_ALEN);
 
         if (vlan->flags & VLAN_FLAG_GVRP)
                 vlan_gvrp_request_join(dev);
 
         return 0;
+
+clear_allmulti:
+        if (dev->flags & IFF_ALLMULTI)
+                dev_set_allmulti(real_dev, -1);
+del_unicast:
+        if (compare_ether_addr(dev->dev_addr, real_dev->dev_addr))
+                dev_unicast_delete(real_dev, dev->dev_addr, ETH_ALEN);
+out:
+        return err;
 }
 
 static int vlan_dev_stop(struct net_device *dev)