From 3a48c3ea04319b95f1c0a84cd51398ed97497f32 Mon Sep 17 00:00:00 2001
From: Jakub Kicinski <jakub.kicinski@netronome.com>
Date: Fri, 18 Oct 2019 09:16:58 -0700
Subject: [PATCH] net: netem: correct the parent's backlog when corrupted
 packet was dropped

commit e0ad032e144731a5928f2d75e91c2064ba1a764c upstream.

If packet corruption failed we jump to finish_segs and return
NET_XMIT_SUCCESS. Seeing success will make the parent qdisc
increment its backlog, that's incorrect - we need to return
NET_XMIT_DROP.

Fixes: 6071bd1aa13e ("netem: Segment GSO packets on enqueue")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index 942eb17f413c..42e557d48e4e 100644
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c
@@ -616,6 +616,8 @@ static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 		}
 		/* Parent qdiscs accounted for 1 skb of size @prev_len */
 		qdisc_tree_reduce_backlog(sch, -(nb - 1), -(len - prev_len));
+	} else if (!skb) {
+		return NET_XMIT_DROP;
 	}
 	return NET_XMIT_SUCCESS;
 }
-- 
2.7.4