Commit df52eab2 authored Oct 09, 2018 by Serhey Popovych Committed by David S. Miller Oct 15, 2018

tun: Consistently configure generic netdev params via rtnetlink



Configuring generic network device parameters on tun will fail in
presence of IFLA_INFO_KIND attribute in IFLA_LINKINFO nested attribute
since tun_validate() always return failure.

This can be visualized with following ip-link(8) command sequences:

  # ip link set dev tun0 group 100
  # ip link set dev tun0 group 100 type tun
  RTNETLINK answers: Invalid argument

with contrast to dummy and veth drivers:

  # ip link set dev dummy0 group 100
  # ip link set dev dummy0 type dummy

  # ip link set dev veth0 group 100
  # ip link set dev veth0 group 100 type veth

Fix by returning zero in tun_validate() when @data is NULL that is
always in case since rtnl_link_ops->maxtype is zero in tun driver.

Fixes: f019a7a5 ("tun: Implement ip link del tunXXX")
Signed-off-by: Serhey Popovych <serhe.popovych@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 921060cc

drivers/net/tun.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -2289,6 +2289,8 @@ static void tun_setup(struct net_device *dev)
		static int tun_validate(struct nlattr tb[], struct nlattr data[],
		struct netlink_ext_ack *extack)
		{
		if (!data)
		return 0;
		return -EINVAL;
		}

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