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Xin Long authored
In the tx path of l2tp, l2tp_xmit_skb() calls skb_dst_set() to set skb's dst. However, it will eventually call inet6_csk_xmit() or ip_queue_xmit() where skb's dst will be overwritten by: skb_dst_set_noref(skb, dst); without releasing the old dst in skb. Then it causes dst/dev refcnt leak: unregister_netdevice: waiting for eth0 to become free. Usage count = 1 This can be reproduced by simply running: # modprobe l2tp_eth && modprobe l2tp_ip # sh ./tools/testing/selftests/net/l2tp.sh So before going to inet6_csk_xmit() or ip_queue_xmit(), skb's dst should be dropped. This patch is to fix it by removing skb_dst_set() from l2tp_xmit_skb() and moving skb_dst_drop() into l2tp_xmit_core(). Fixes: 3557baab ("[L2TP]: PPP over L2TP driver core") Reported-by:
Hangbin Liu <liuhangbin@gmail.com> Signed-off-by:
Xin Long <lucien.xin@gmail.com> Acked-by:
James Chapman <jchapman@katalix.com> Tested-by:
James Chapman <jchapman@katalix.com> Signed-off-by:
David S. Miller <davem@davemloft.net>
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