My previous commits added a dev_hold() in tunnels ndo_init(),
but forgot to remove it from special functions setting up fallback tunnels.
Fallback tunnels do call their respective ndo_init()
This leads to various reports like :
unregister_netdevice: waiting for ip6gre0 to become free. Usage count = 2
Fixes: 48bb5697269a ("ip6_tunnel: sit: proper dev_{hold|put} in ndo_[un]init methods")
Fixes: 6289a98f0817 ("sit: proper dev_{hold|put} in ndo_[un]init methods")
Fixes: 40cb881b5aaa ("ip6_vti: proper dev_{hold|put} in ndo_[un]init methods")
Fixes: 7f700334be9a ("ip6_gre: proper dev_{hold|put} in ndo_[un]init methods")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
        if (!(nt->parms.o_flags & TUNNEL_SEQ))
                dev->features |= NETIF_F_LLTX;
 
-       dev_hold(dev);
        ip6gre_tunnel_link(ign, nt);
        return nt;
 
        strcpy(tunnel->parms.name, dev->name);
 
        tunnel->hlen            = sizeof(struct ipv6hdr) + 4;
-
-       dev_hold(dev);
 }
 
 static struct inet6_protocol ip6gre_protocol __read_mostly = {
 
        struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 
        t->parms.proto = IPPROTO_IPV6;
-       dev_hold(dev);
 
        rcu_assign_pointer(ip6n->tnls_wc[0], t);
        return 0;
 
        struct vti6_net *ip6n = net_generic(net, vti6_net_id);
 
        t->parms.proto = IPPROTO_IPV6;
-       dev_hold(dev);
 
        rcu_assign_pointer(ip6n->tnls_wc[0], t);
        return 0;
 
        iph->ihl                = 5;
        iph->ttl                = 64;
 
-       dev_hold(dev);
        rcu_assign_pointer(sitn->tunnels_wc[0], tunnel);
 }