4.4-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit 7f92083eb58f85ea114d97f65fcbe22be5b0468d ]
This is the same fix than commit a5d0dc810abf ("vti: flush x-netns xfrm cache when vti interface is removed")
This patch fixes a refcnt problem when a x-netns vti6 interface is removed: unregister_netdevice: waiting for vti6_test to become free. Usage count = 1
Here is a script to reproduce the problem:
ip link set dev ntfp2 up ip addr add dev ntfp2 2001::1/64 ip link add vti6_test type vti6 local 2001::1 remote 2001::2 key 1 ip netns add secure ip link set vti6_test netns secure ip netns exec secure ip link set vti6_test up ip netns exec secure ip link s lo up ip netns exec secure ip addr add dev vti6_test 2003::1/64 ip -6 xfrm policy add dir out tmpl src 2001::1 dst 2001::2 proto esp \ mode tunnel mark 1 ip -6 xfrm policy add dir in tmpl src 2001::2 dst 2001::1 proto esp \ mode tunnel mark 1 ip xfrm state add src 2001::1 dst 2001::2 proto esp spi 1 mode tunnel \ enc des3_ede 0x112233445566778811223344556677881122334455667788 mark 1 ip xfrm state add src 2001::2 dst 2001::1 proto esp spi 1 mode tunnel \ enc des3_ede 0x112233445566778811223344556677881122334455667788 mark 1 ip netns exec secure ping6 -c 4 2003::2 ip netns del secure
CC: Lance Richardson lrichard@redhat.com Signed-off-by: Nicolas Dichtel nicolas.dichtel@6wind.com Acked-by: Lance Richardson lrichard@redhat.com Signed-off-by: Steffen Klassert steffen.klassert@secunet.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/ipv6/ip6_vti.c | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+)
diff --git a/net/ipv6/ip6_vti.c b/net/ipv6/ip6_vti.c index 60d4052d97a6..51da5987952c 100644 --- a/net/ipv6/ip6_vti.c +++ b/net/ipv6/ip6_vti.c @@ -1140,6 +1140,33 @@ static struct xfrm6_protocol vti_ipcomp6_protocol __read_mostly = { .priority = 100, };
+static bool is_vti6_tunnel(const struct net_device *dev) +{ + return dev->netdev_ops == &vti6_netdev_ops; +} + +static int vti6_device_event(struct notifier_block *unused, + unsigned long event, void *ptr) +{ + struct net_device *dev = netdev_notifier_info_to_dev(ptr); + struct ip6_tnl *t = netdev_priv(dev); + + if (!is_vti6_tunnel(dev)) + return NOTIFY_DONE; + + switch (event) { + case NETDEV_DOWN: + if (!net_eq(t->net, dev_net(dev))) + xfrm_garbage_collect(t->net); + break; + } + return NOTIFY_DONE; +} + +static struct notifier_block vti6_notifier_block __read_mostly = { + .notifier_call = vti6_device_event, +}; + /** * vti6_tunnel_init - register protocol and reserve needed resources * @@ -1150,6 +1177,8 @@ static int __init vti6_tunnel_init(void) const char *msg; int err;
+ register_netdevice_notifier(&vti6_notifier_block); + msg = "tunnel device"; err = register_pernet_device(&vti6_net_ops); if (err < 0) @@ -1182,6 +1211,7 @@ xfrm_proto_ah_failed: xfrm_proto_esp_failed: unregister_pernet_device(&vti6_net_ops); pernet_dev_failed: + unregister_netdevice_notifier(&vti6_notifier_block); pr_err("vti6 init: failed to register %s\n", msg); return err; } @@ -1196,6 +1226,7 @@ static void __exit vti6_tunnel_cleanup(void) xfrm6_protocol_deregister(&vti_ah6_protocol, IPPROTO_AH); xfrm6_protocol_deregister(&vti_esp6_protocol, IPPROTO_ESP); unregister_pernet_device(&vti6_net_ops); + unregister_netdevice_notifier(&vti6_notifier_block); }
module_init(vti6_tunnel_init);