4.18-stable review patch. If anyone has any objections, please let me know.
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From: Serhey Popovych serhe.popovych@gmail.com
[ Upstream commit df52eab23d703142c766ac00bdb8db19d71238d0 ]
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: f019a7a594d9 ("tun: Implement ip link del tunXXX") Signed-off-by: Serhey Popovych serhe.popovych@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/tun.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -2304,6 +2304,8 @@ static void tun_setup(struct net_device static int tun_validate(struct nlattr *tb[], struct nlattr *data[], struct netlink_ext_ack *extack) { + if (!data) + return 0; return -EINVAL; }