kernel_optimize_test/net/l2tp
Xin Long 27d5332366 l2tp: remove skb_dst_set() from l2tp_xmit_skb()
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: 3557baabf2 ("[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>
2020-07-08 15:24:33 -07:00
..
Kconfig treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
l2tp_core.c l2tp: remove skb_dst_set() from l2tp_xmit_skb() 2020-07-08 15:24:33 -07:00
l2tp_core.h l2tp: Replace zero-length array with flexible-array member 2020-02-28 12:08:37 -08:00
l2tp_debugfs.c l2tp: no need to check return value of debugfs_create functions 2019-06-14 08:45:05 -07:00
l2tp_eth.c net: partially revert dynamic lockdep key changes 2020-05-04 12:05:56 -07:00
l2tp_ip.c l2tp: do not use inet_hash()/inet_unhash() 2020-05-30 21:55:16 -07:00
l2tp_ip6.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-05-31 17:48:46 -07:00
l2tp_netlink.c l2tp: Allow management of tunnels and session in user namespace 2020-04-08 14:30:46 -07:00
l2tp_ppp.c compat_ioctl: pppoe: fix PPPOEIOCSFWD handling 2019-07-30 14:42:13 -07:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00