[PATCH] udp: increment UDP_MIB_INERRORS if copy failed

[Eric Dumazet <eric.dumazet@gmail.com>]

From: Eric Dumazet <edumazet@google.com>

In UDP recvmsg(), we miss an increase of UDP_MIB_INERRORS if the copy
of skb to userspace failed for whatever reason.

Reported-by: Shawn Bohrer <sbohrer@rgmadvisors.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 net/ipv4/udp.c |    5 +++++
 net/ipv6/udp.c |   11 +++++++++++
 2 files changed, 16 insertions(+)

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 6f6d1ac..2814f66 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1226,6 +1226,11 @@ try_again:
 
 	if (unlikely(err)) {
 		trace_kfree_skb(skb, udp_recvmsg);
+		if (!peeked) {
+			atomic_inc(&sk->sk_drops);
+			UDP_INC_STATS_USER(sock_net(sk),
+					   UDP_MIB_INERRORS, is_udplite);
+		}
 		goto out_free;
 	}
 
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 99d0077..07e2bfe 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -394,6 +394,17 @@ try_again:
 	}
 	if (unlikely(err)) {
 		trace_kfree_skb(skb, udpv6_recvmsg);
+		if (!peeked) {
+			atomic_inc(&sk->sk_drops);
+			if (is_udp4)
+				UDP_INC_STATS_USER(sock_net(sk),
+						   UDP_MIB_INERRORS,
+						   is_udplite);
+			else
+				UDP6_INC_STATS_USER(sock_net(sk),
+						    UDP_MIB_INERRORS,
+						    is_udplite);
+		}
 		goto out_free;
 	}
 	if (!peeked) {