4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Serhey Popovych <serhe.popovych@xxxxxxxxx>
[ 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@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/tun.c | 2 ++
1 file changed, 2 insertions(+)
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -2264,6 +2264,8 @@ 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;
}
