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 6cbc6e979bed74c422f008c2a0a9a1ca79ee0d8e..043e57d08a3e9fa165afbc308061734fb645b350 100644 (file)
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -392,7 +392,6 @@ 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;
 
@@ -1546,8 +1545,6 @@ 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 45c4c30d9806d670aa6dad7f544aea67dffd03f7..35c127c3eee78b35d00b6cb28c796a55ad1147bb 100644 (file)
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -1909,7 +1909,6 @@ 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 defa04b38ee8d195b8d7dd7df0f06d679e687eb8..290badfe70e06e61c0368bfc050cb2cefea1308e 100644 (file)
--- a/net/ipv6/ip6_vti.c
+++ b/net/ipv6/ip6_vti.c
@@ -956,7 +956,6 @@ 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 c77e9b02ac007455e5b06989ce3adf637a9bedbc..4a49200d0d11c6eec53f661ab887db1a5f10b6fb 100644 (file)
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -1421,7 +1421,6 @@ 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);
 }