From: Jakub Kicinski <kuba@xxxxxxxxxx> [ Upstream commit 47e4bb147a96f1c9b4e7691e7e994e53838bfff8 ] We need to unregister the netdevice if config failed. .ndo_uninit takes care of most of the heavy lifting. This was uncovered by recent commit c269a24ce057 ("net: make free_netdev() more lenient with unregistering devices"). Previously the partially-initialized device would be left in the system. Reported-and-tested-by: syzbot+2393580080a2da190f04@xxxxxxxxxxxxxxxxxxxxxxxxx Fixes: e2f1f072db8d ("sit: allow to configure 6rd tunnels via netlink") Acked-by: Nicolas Dichtel <nicolas.dichtel@xxxxxxxxx> Link: https://lore.kernel.org/r/20210114012947.2515313-1-kuba@xxxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/ipv6/sit.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/net/ipv6/sit.c +++ b/net/ipv6/sit.c @@ -1596,8 +1596,11 @@ static int ipip6_newlink(struct net *src } #ifdef CONFIG_IPV6_SIT_6RD - if (ipip6_netlink_6rd_parms(data, &ip6rd)) + if (ipip6_netlink_6rd_parms(data, &ip6rd)) { err = ipip6_tunnel_update_6rd(nt, &ip6rd); + if (err < 0) + unregister_netdevice_queue(dev, NULL); + } #endif return err;