[PATCH 4.19 177/229] openvswitch: Fix double reporting of drops in dropwatch

[Greg Kroah-Hartman]

From: Mike Pattrick <mkp@xxxxxxxxxx>

[ Upstream commit 1100248a5c5ccd57059eb8d02ec077e839a23826 ]

Frames sent to userspace can be reported as dropped in
ovs_dp_process_packet, however, if they are dropped in the netlink code
then netlink_attachskb will report the same frame as dropped.

This patch checks for error codes which indicate that the frame has
already been freed.

Signed-off-by: Mike Pattrick <mkp@xxxxxxxxxx>
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2109946
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 net/openvswitch/datapath.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index f350faef044d..a9868e97db45 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -249,10 +249,17 @@ void ovs_dp_process_packet(struct sk_buff *skb, struct sw_flow_key *key)
 		upcall.portid = ovs_vport_find_upcall_portid(p, skb);
 		upcall.mru = OVS_CB(skb)->mru;
 		error = ovs_dp_upcall(dp, skb, key, &upcall, 0);
-		if (unlikely(error))
-			kfree_skb(skb);
-		else
+		switch (error) {
+		case 0:
+		case -EAGAIN:
+		case -ERESTARTSYS:
+		case -EINTR:
 			consume_skb(skb);
+			break;
+		default:
+			kfree_skb(skb);
+			break;
+		}
 		stats_counter = &stats->n_missed;
 		goto out;
 	}
-- 
2.35.1