On 02/28/2019 02:47 AM, Sheng Lan wrote:

From: Sheng Lan <redacted>

It can be reproduced by following steps:
1. virtio_net NIC is configured with gso/tso on
2. configure nginx as http server with an index file bigger than 1M bytes
3. use tc netem to produce duplicate packets and delay:
   tc qdisc add dev eth0 root netem delay 100ms 10ms 30% duplicate 90%
4. continually curl the nginx http server to get index file on client
5. BUG_ON is seen quickly

...

To fix it, netem returns NET_XMIT_SUCCESS to upper stack
when it clones a duplicate packet.

Fixes: 35d889d1 ("sch_netem: fix skb leak in netem_enqueue()")
Signed-off-by: Sheng Lan <redacted>
Reported-by: Qin Ji <redacted>
Suggested-by: Eric Dumazet <redacted>

---

Signed-off-by: Eric Dumazet <edumazet@google.com>

Thanks.