[PATCH net-next] net: better drop monitoring in ip{6}_recv_error()

[Eric Dumazet]

From: Eric Dumazet <eduma...@google.com>

We should call consume_skb(skb) when skb is properly consumed,
or kfree_skb(skb) when skb must be dropped in error case.

Signed-off-by: Eric Dumazet <eduma...@google.com>
---
 net/ipv4/ip_sockglue.c |   10 +++++-----
 net/ipv6/datagram.c    |   10 +++++-----
 2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 279471c4e58f..e3ca3915dc74 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -510,9 +510,10 @@ int ip_recv_error(struct sock *sk, struct msghdr *msg, int 
len, int *addr_len)
                copied = len;
        }
        err = skb_copy_datagram_msg(skb, 0, msg, copied);
-       if (err)
-               goto out_free_skb;
-
+       if (unlikely(err)) {
+               kfree_skb(skb);
+               return err;
+       }
        sock_recv_timestamp(msg, sk, skb);
 
        serr = SKB_EXT_ERR(skb);
@@ -544,8 +545,7 @@ int ip_recv_error(struct sock *sk, struct msghdr *msg, int 
len, int *addr_len)
        msg->msg_flags |= MSG_ERRQUEUE;
        err = copied;
 
-out_free_skb:
-       kfree_skb(skb);
+       consume_skb(skb);
 out:
        return err;
 }
diff --git a/net/ipv6/datagram.c b/net/ipv6/datagram.c
index a73d70119fcd..4b33e54c5753 100644
--- a/net/ipv6/datagram.c
+++ b/net/ipv6/datagram.c
@@ -407,9 +407,10 @@ int ipv6_recv_error(struct sock *sk, struct msghdr *msg, 
int len, int *addr_len)
                copied = len;
        }
        err = skb_copy_datagram_msg(skb, 0, msg, copied);
-       if (err)
-               goto out_free_skb;
-
+       if (unlikely(err)) {
+               kfree_skb(skb);
+               return err;
+       }
        sock_recv_timestamp(msg, sk, skb);
 
        serr = SKB_EXT_ERR(skb);
@@ -466,8 +467,7 @@ int ipv6_recv_error(struct sock *sk, struct msghdr *msg, 
int len, int *addr_len)
        msg->msg_flags |= MSG_ERRQUEUE;
        err = copied;
 
-out_free_skb:
-       kfree_skb(skb);
+       consume_skb(skb);
 out:
        return err;
 }