ipv6: remove extra dev_hold() for fallback tunnels

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: 48bb569 ("ip6_tunnel: sit: proper dev_{hold|put} in ndo_[un]init methods") Fixes: 6289a98 ("sit: proper dev_{hold|put} in ndo_[un]init methods") Fixes: 40cb881 ("ip6_vti: proper dev_{hold|put} in ndo_[un]init methods") Fixes: 7f70033 ("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>
mariux64 · Mar 31, 2021 · 0d7a7b2 · 0d7a7b2
1 parent ac1db7a
commit 0d7a7b2
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Showing 4 changed files with 0 additions and 6 deletions.
diff --git 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
@@ -1925,7 +1925,6 @@ 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
@@ -963,7 +963,6 @@ 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
@@ -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);
 }