[PATCH 4.4 87/92] openvswitch: remove another BUG_ON()

[Greg Kroah-Hartman]

From: Paolo Abeni <pabeni@xxxxxxxxxx>

[ Upstream commit 8a574f86652a4540a2433946ba826ccb87f398cc ]

If we can't build the flow del notification, we can simply delete
the flow, no need to crash the kernel. Still keep a WARN_ON to
preserve debuggability.

Note: the BUG_ON() predates the Fixes tag, but this change
can be applied only after the mentioned commit.

v1 -> v2:
 - do not leak an skb on error

Fixes: aed067783e50 ("openvswitch: Minimize ovs_flow_cmd_del critical section.")
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 net/openvswitch/datapath.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -1325,7 +1325,10 @@ static int ovs_flow_cmd_del(struct sk_bu
 						     OVS_FLOW_CMD_DEL,
 						     ufid_flags);
 			rcu_read_unlock();
-			BUG_ON(err < 0);
+			if (WARN_ON_ONCE(err < 0)) {
+				kfree_skb(reply);
+				goto out_free;
+			}
 
 			ovs_notify(&dp_flow_genl_family, reply, info);
 		} else {
@@ -1333,6 +1336,7 @@ static int ovs_flow_cmd_del(struct sk_bu
 		}
 	}
 
+out_free:
 	ovs_flow_free(flow, true);
 	return 0;
 unlock: