ethtool: Fix filter addition when caching n-tuple filters

We can allow a filter to be added successfully to the underlying
hardware, but still return an error if the cached list memory
allocation fails.  This patch fixes that condition.

Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index a1280f6..fbbe4b4 100644 (file)
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -283,18 +283,17 @@ err_out:
        return ret;
 }
 
-static int __rx_ntuple_filter_add(struct ethtool_rx_ntuple_list *list,
-                                  struct ethtool_rx_ntuple_flow_spec *spec)
+static void __rx_ntuple_filter_add(struct ethtool_rx_ntuple_list *list,
+                              struct ethtool_rx_ntuple_flow_spec *spec,
+                              struct ethtool_rx_ntuple_flow_spec_container *fsc)
 {
-       struct ethtool_rx_ntuple_flow_spec_container *fsc;
 
        /* don't add filters forever */
-       if (list->count >= ETHTOOL_MAX_NTUPLE_LIST_ENTRY)
-               return 0;
-
-       fsc = kmalloc(sizeof(*fsc), GFP_ATOMIC);
-       if (!fsc)
-               return -ENOMEM;
+       if (list->count >= ETHTOOL_MAX_NTUPLE_LIST_ENTRY) {
+               /* free the container */
+               kfree(fsc);
+               return;
+       }
 
        /* Copy the whole filter over */
        fsc->fs.flow_type = spec->flow_type;
@@ -310,14 +309,13 @@ static int __rx_ntuple_filter_add(struct ethtool_rx_ntuple_list *list,
        /* add to the list */
        list_add_tail_rcu(&fsc->list, &list->list);
        list->count++;
-
-       return 0;
 }
 
 static int ethtool_set_rx_ntuple(struct net_device *dev, void __user *useraddr)
 {
        struct ethtool_rx_ntuple cmd;
        const struct ethtool_ops *ops = dev->ethtool_ops;
+       struct ethtool_rx_ntuple_flow_spec_container *fsc = NULL;
        int ret;
 
        if (!ops->set_rx_ntuple)
@@ -329,16 +327,26 @@ static int ethtool_set_rx_ntuple(struct net_device *dev, void __user *useraddr)
        if (copy_from_user(&cmd, useraddr, sizeof(cmd)))
                return -EFAULT;
 
-       ret = ops->set_rx_ntuple(dev, &cmd);
-
        /*
         * Cache filter in dev struct for GET operation only if
         * the underlying driver doesn't have its own GET operation, and
-        * only if the filter was added successfully.
+        * only if the filter was added successfully.  First make sure we
+        * can allocate the filter, then continue if successful.
         */
-       if (!ops->get_rx_ntuple && !ret)
-               if (__rx_ntuple_filter_add(&dev->ethtool_ntuple_list, &cmd.fs))
+       if (!ops->get_rx_ntuple) {
+               fsc = kmalloc(sizeof(*fsc), GFP_ATOMIC);
+               if (!fsc)
                        return -ENOMEM;
+       }
+
+       ret = ops->set_rx_ntuple(dev, &cmd);
+       if (ret) {
+               kfree(fsc);
+               return ret;
+       }
+
+       if (!ops->get_rx_ntuple)
+               __rx_ntuple_filter_add(&dev->ethtool_ntuple_list, &cmd.fs, fsc);
 
        return ret;
 }