ipv6: remove extra dev_hold() for fallback tunnels

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>

diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index d4319d4..09fa49b 100644 (file)
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -387,7 +387,6 @@ static struct ip6_tnl *ip6gre_tunnel_locate(struct net *net,
        if (!(nt->parms.o_flags & TUNNEL_SEQ))
                dev->features |= NETIF_F_LLTX;
 
-       dev_hold(dev);
        ip6gre_tunnel_link(ign, nt);
        return nt;
 
@@ -1539,8 +1538,6 @@ static void ip6gre_fb_tunnel_init(struct net_device *dev)
        strcpy(tunnel->parms.name, dev->name);
 
        tunnel->hlen            = sizeof(struct ipv6hdr) + 4;
-
-       dev_hold(dev);
 }
 
 static struct inet6_protocol ip6gre_protocol __read_mostly = {

diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index 0fc21cf..42ca2d0 100644 (file)
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -1956,7 +1956,6 @@ static int __net_init ip6_fb_tnl_dev_init(struct net_device *dev)
        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;

diff --git a/net/ipv6/ip6_vti.c b/net/ipv6/ip6_vti.c
index 82961ff..23aeeb4 100644 (file)
--- a/net/ipv6/ip6_vti.c
+++ b/net/ipv6/ip6_vti.c
@@ -962,7 +962,6 @@ static int __net_init vti6_fb_tnl_dev_init(struct net_device *dev)
        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;

diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index 22edda1..a6a3d75 100644 (file)
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -1470,7 +1470,6 @@ static void __net_init ipip6_fb_tunnel_init(struct net_device *dev)
        iph->ihl                = 5;
        iph->ttl                = 64;
 
-       dev_hold(dev);
        rcu_assign_pointer(sitn->tunnels_wc[0], tunnel);
 }