net: bridge: vlan: fix single net device option dumping

When dumping vlan options for a single net device we send the same entries infinitely because user-space expects a 0 return at the end but we keep returning skb->len and restarting the dump on retry. Fix it by returning the value from br_vlan_dump_dev() if it completed or there was an error. The only case that must return skb->len is when the dump was incomplete and needs to continue (-EMSGSIZE). Reported-by: Benjamin Poirier <[email protected]> Fixes: 8dcea18 ("net: bridge: vlan: add rtm definitions and dump support") Signed-off-by: Nikolay Aleksandrov <[email protected]> Signed-off-by: David S. Miller <[email protected]>
josf · Jan 27, 2022 · dcb2c5c · dcb2c5c
1 parent aa44323
commit dcb2c5c
Showing 1 changed file with 2 additions and 1 deletion.
diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
@@ -2020,7 +2020,8 @@ static int br_vlan_rtm_dump(struct sk_buff *skb, struct netlink_callback *cb)
 			goto out_err;
 		}
 		err = br_vlan_dump_dev(dev, skb, cb, dump_flags);
-		if (err && err != -EMSGSIZE)
+		/* if the dump completed without an error we return 0 here */
+		if (err != -EMSGSIZE)
 			goto out_err;
 	} else {
 		for_each_netdev_rcu(net, dev) {