This is a note to let you know that I've just added the patch titled
ipv6: remove extra dev_hold() for fallback tunnels
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ipv6-remove-extra-dev_hold-for-fallback-tunnels.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 0d7a7b2014b1a499a0fe24c9f3063d7856b5aaaf Mon Sep 17 00:00:00 2001
From: Eric Dumazet <edumazet@xxxxxxxxxx>
Date: Wed, 31 Mar 2021 14:38:11 -0700
Subject: ipv6: remove extra dev_hold() for fallback tunnels
From: Eric Dumazet <edumazet@xxxxxxxxxx>
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@xxxxxxxxxx>
Reported-by: syzbot <syzkaller@xxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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 & TUNNEL_SEQ))
dev->features |= NETIF_F_LLTX;
- dev_hold(dev);
ip6gre_tunnel_link(ign, nt);
return nt;
@@ -1085,8 +1084,6 @@ 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
@@ -1888,7 +1888,6 @@ 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
@@ -945,7 +945,6 @@ 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
@@ -1414,7 +1414,6 @@ 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);
}
Patches currently in stable-queue which might be from edumazet@xxxxxxxxxx are
queue-4.9/ip6_tunnel-sit-proper-dev_-hold-put-in-ndo_init-methods.patch
queue-4.9/sit-proper-dev_-hold-put-in-ndo_init-methods.patch
queue-4.9/ip6_vti-proper-dev_-hold-put-in-ndo_-un-init-methods.patch
queue-4.9/ipv6-remove-extra-dev_hold-for-fallback-tunnels.patch
