af_netlink: drop_monitor/dropwatch friendly

Need to consume_skb() instead of kfree_skb() in netlink_dump() and
netlink_unicast_kernel() to avoid false dropwatch positives.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 10 insertions, 2 deletions

diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 85d27f9f0e67..b3025a603d56 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -154,6 +154,12 @@ static void netlink_destroy_callback(struct netlink_callback *cb)
         kfree(cb);
 }
 
+static void netlink_consume_callback(struct netlink_callback *cb)
+{
+        consume_skb(cb->skb);
+        kfree(cb);
+}
+
 static void netlink_sock_destruct(struct sock *sk)
 {
         struct netlink_sock *nlk = nlk_sk(sk);
@@ -902,8 +908,10 @@ static int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb)
                 ret = skb->len;
                 skb_set_owner_r(skb, sk);
                 nlk->netlink_rcv(skb);
+                consume_skb(skb);
+        } else {
+                kfree_skb(skb);
         }
-        kfree_skb(skb);
         sock_put(sk);
         return ret;
 }
@@ -1728,7 +1736,7 @@ static int netlink_dump(struct sock *sk)
         nlk->cb = NULL;
         mutex_unlock(nlk->cb_mutex);
 
-        netlink_destroy_callback(cb);
+        netlink_consume_callback(cb);
         return 0;
 
 errout_skb: