[PATCH 5.4 193/255] openvswitch: Fix double reporting of drops in dropwatch

From: Greg Kroah-Hartman
Date: Mon Oct 24 2022 - 09:21:30 EST


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 4f097bd3339e..63f36d6cd3f6 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -236,10 +236,17 @@ 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