veth: Free queues on link delete

David Ahern reported memory leak in veth.

=======================================================================
$ cat /sys/kernel/debug/kmemleak
unreferenced object 0xffff8800354d5c00 (size 1024):
  comm "ip", pid 836, jiffies 4294722952 (age 25.904s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<(____ptrval____)>] kmemleak_alloc+0x70/0x94
    [<(____ptrval____)>] slab_post_alloc_hook+0x42/0x52
    [<(____ptrval____)>] __kmalloc+0x101/0x142
    [<(____ptrval____)>] kmalloc_array.constprop.20+0x1e/0x26 [veth]
    [<(____ptrval____)>] veth_newlink+0x147/0x3ac [veth]
    ...
unreferenced object 0xffff88002e009c00 (size 1024):
  comm "ip", pid 836, jiffies 4294722958 (age 25.898s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<(____ptrval____)>] kmemleak_alloc+0x70/0x94
    [<(____ptrval____)>] slab_post_alloc_hook+0x42/0x52
    [<(____ptrval____)>] __kmalloc+0x101/0x142
    [<(____ptrval____)>] kmalloc_array.constprop.20+0x1e/0x26 [veth]
    [<(____ptrval____)>] veth_newlink+0x219/0x3ac [veth]
=======================================================================

veth_rq allocated in veth_newlink() was not freed on dellink.

We need to free up them after veth_close() so that any packets will not
reference the queues afterwards. Thus free them in veth_dev_free() in
the same way as freeing stats structure (vstats).

Also move queues allocation to veth_dev_init() to be in line with stats
allocation.

Fixes: 638264dc90227 ("veth: Support per queue XDP ring")
Reported-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Reviewed-by: David Ahern <dsahern@gmail.com>
Tested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/veth.c b/drivers/net/veth.c
index e3202af72df5140437148e0804424b95776d2cc0..8d679c8b7f25c753d77cfb8821d9d2528c9c9048 100644 (file)
--- a/drivers/net/veth.c
+++ b/drivers/net/veth.c
@@ -789,16 +789,48 @@ static int is_valid_veth_mtu(int mtu)
        return mtu >= ETH_MIN_MTU && mtu <= ETH_MAX_MTU;
 }
 
+static int veth_alloc_queues(struct net_device *dev)
+{
+       struct veth_priv *priv = netdev_priv(dev);
+       int i;
+
+       priv->rq = kcalloc(dev->num_rx_queues, sizeof(*priv->rq), GFP_KERNEL);
+       if (!priv->rq)
+               return -ENOMEM;
+
+       for (i = 0; i < dev->num_rx_queues; i++)
+               priv->rq[i].dev = dev;
+
+       return 0;
+}
+
+static void veth_free_queues(struct net_device *dev)
+{
+       struct veth_priv *priv = netdev_priv(dev);
+
+       kfree(priv->rq);
+}
+
 static int veth_dev_init(struct net_device *dev)
 {
+       int err;
+
        dev->vstats = netdev_alloc_pcpu_stats(struct pcpu_vstats);
        if (!dev->vstats)
                return -ENOMEM;
+
+       err = veth_alloc_queues(dev);
+       if (err) {
+               free_percpu(dev->vstats);
+               return err;
+       }
+
        return 0;
 }
 
 static void veth_dev_free(struct net_device *dev)
 {
+       veth_free_queues(dev);
        free_percpu(dev->vstats);
 }
 
@@ -1040,31 +1072,13 @@ static int veth_validate(struct nlattr *tb[], struct nlattr *data[],
        return 0;
 }
 
-static int veth_alloc_queues(struct net_device *dev)
-{
-       struct veth_priv *priv = netdev_priv(dev);
-
-       priv->rq = kcalloc(dev->num_rx_queues, sizeof(*priv->rq), GFP_KERNEL);
-       if (!priv->rq)
-               return -ENOMEM;
-
-       return 0;
-}
-
-static void veth_free_queues(struct net_device *dev)
-{
-       struct veth_priv *priv = netdev_priv(dev);
-
-       kfree(priv->rq);
-}
-
 static struct rtnl_link_ops veth_link_ops;
 
 static int veth_newlink(struct net *src_net, struct net_device *dev,
                        struct nlattr *tb[], struct nlattr *data[],
                        struct netlink_ext_ack *extack)
 {
-       int err, i;
+       int err;
        struct net_device *peer;
        struct veth_priv *priv;
        char ifname[IFNAMSIZ];
@@ -1117,12 +1131,6 @@ static int veth_newlink(struct net *src_net, struct net_device *dev,
                return PTR_ERR(peer);
        }
 
-       err = veth_alloc_queues(peer);
-       if (err) {
-               put_net(net);
-               goto err_peer_alloc_queues;
-       }
-
        if (!ifmp || !tbp[IFLA_ADDRESS])
                eth_hw_addr_random(peer);
 
@@ -1151,10 +1159,6 @@ static int veth_newlink(struct net *src_net, struct net_device *dev,
         * should be re-allocated
         */
 
-       err = veth_alloc_queues(dev);
-       if (err)
-               goto err_alloc_queues;
-
        if (tb[IFLA_ADDRESS] == NULL)
                eth_hw_addr_random(dev);
 
@@ -1174,28 +1178,20 @@ static int veth_newlink(struct net *src_net, struct net_device *dev,
         */
 
        priv = netdev_priv(dev);
-       for (i = 0; i < dev->real_num_rx_queues; i++)
-               priv->rq[i].dev = dev;
        rcu_assign_pointer(priv->peer, peer);
 
        priv = netdev_priv(peer);
-       for (i = 0; i < peer->real_num_rx_queues; i++)
-               priv->rq[i].dev = peer;
        rcu_assign_pointer(priv->peer, dev);
 
        return 0;
 
 err_register_dev:
-       veth_free_queues(dev);
-err_alloc_queues:
        /* nothing to do */
 err_configure_peer:
        unregister_netdevice(peer);
        return err;
 
 err_register_peer:
-       veth_free_queues(peer);
-err_peer_alloc_queues:
        free_netdev(peer);
        return err;
 }