udp: increment UDP_MIB_INERRORS if copy failed

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>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 16 insertions, 0 deletions

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 6f6d1aca3c3d..2814f66dac64 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 99d0077b56b8..07e2bfef6845 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) {