From: Eric Dumazet edumazet@google.com
commit 0d7a7b2014b1a499a0fe24c9f3063d7856b5aaaf upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/ipv6/ip6_gre.c | 3 --- net/ipv6/ip6_tunnel.c | 1 - net/ipv6/ip6_vti.c | 1 - net/ipv6/sit.c | 1 - 4 files changed, 6 deletions(-)
--- a/net/ipv6/ip6_gre.c +++ b/net/ipv6/ip6_gre.c @@ -350,7 +350,6 @@ static struct ip6_tnl *ip6gre_tunnel_loc if (!(nt->parms.o_flags & GRE_SEQ)) dev->features |= NETIF_F_LLTX;
- dev_hold(dev); ip6gre_tunnel_link(ign, nt); return nt;
@@ -1310,8 +1309,6 @@ static void ip6gre_fb_tunnel_init(struct strcpy(tunnel->parms.name, dev->name);
tunnel->hlen = sizeof(struct ipv6hdr) + 4; - - dev_hold(dev); }
--- a/net/ipv6/ip6_tunnel.c +++ b/net/ipv6/ip6_tunnel.c @@ -1614,7 +1614,6 @@ static int __net_init ip6_fb_tnl_dev_ini 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; --- a/net/ipv6/ip6_vti.c +++ b/net/ipv6/ip6_vti.c @@ -931,7 +931,6 @@ static int __net_init vti6_fb_tnl_dev_in 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; --- a/net/ipv6/sit.c +++ b/net/ipv6/sit.c @@ -1413,7 +1413,6 @@ static void __net_init ipip6_fb_tunnel_i iph->ihl = 5; iph->ttl = 64;
- dev_hold(dev); rcu_assign_pointer(sitn->tunnels_wc[0], tunnel); }