3.16.48-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: WANG Cong <xiyou.wangcong@xxxxxxxxx> commit 242d3a49a2a1a71d8eb9f953db1bcaa9d698ce00 upstream. For each netns (except init_net), we initialize its null entry in 3 places: 1) The template itself, as we use kmemdup() 2) Code around dst_init_metrics() in ip6_route_net_init() 3) ip6_route_dev_notify(), which is supposed to initialize it after loopback registers Unfortunately the last one still happens in a wrong order because we expect to initialize net->ipv6.ip6_null_entry->rt6i_idev to net->loopback_dev's idev, thus we have to do that after we add idev to loopback. However, this notifier has priority == 0 same as ipv6_dev_notf, and ipv6_dev_notf is registered after ip6_route_dev_notifier so it is called actually after ip6_route_dev_notifier. This is similar to commit 2f460933f58e ("ipv6: initialize route null entry in addrconf_init()") which fixes init_net. Fix it by picking a smaller priority for ip6_route_dev_notifier. Also, we have to release the refcnt accordingly when unregistering loopback_dev because device exit functions are called before subsys exit functions. Acked-by: David Ahern <dsahern@xxxxxxxxx> Tested-by: David Ahern <dsahern@xxxxxxxxx> Signed-off-by: Cong Wang <xiyou.wangcong@xxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx> --- include/net/addrconf.h | 2 ++ net/ipv6/addrconf.c | 1 + net/ipv6/route.c | 13 +++++++++++-- 3 files changed, 14 insertions(+), 2 deletions(-) --- a/include/net/addrconf.h +++ b/include/net/addrconf.h @@ -19,6 +19,8 @@ #define ADDRCONF_TIMER_FUZZ (HZ / 4) #define ADDRCONF_TIMER_FUZZ_MAX (HZ) +#define ADDRCONF_NOTIFY_PRIORITY 0 + #include <linux/in.h> #include <linux/in6.h> --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -2971,6 +2971,7 @@ static int addrconf_notify(struct notifi */ static struct notifier_block ipv6_dev_notf = { .notifier_call = addrconf_notify, + .priority = ADDRCONF_NOTIFY_PRIORITY, }; static void addrconf_type_change(struct net_device *dev, unsigned long event) --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -2823,7 +2823,10 @@ static int ip6_route_dev_notify(struct n struct net_device *dev = netdev_notifier_info_to_dev(ptr); struct net *net = dev_net(dev); - if (event == NETDEV_REGISTER && (dev->flags & IFF_LOOPBACK)) { + if (!(dev->flags & IFF_LOOPBACK)) + return NOTIFY_OK; + + if (event == NETDEV_REGISTER) { net->ipv6.ip6_null_entry->dst.dev = dev; net->ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(dev); #ifdef CONFIG_IPV6_MULTIPLE_TABLES @@ -2832,6 +2835,12 @@ static int ip6_route_dev_notify(struct n net->ipv6.ip6_blk_hole_entry->dst.dev = dev; net->ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(dev); #endif + } else if (event == NETDEV_UNREGISTER) { + in6_dev_put(net->ipv6.ip6_null_entry->rt6i_idev); +#ifdef CONFIG_IPV6_MULTIPLE_TABLES + in6_dev_put(net->ipv6.ip6_prohibit_entry->rt6i_idev); + in6_dev_put(net->ipv6.ip6_blk_hole_entry->rt6i_idev); +#endif } return NOTIFY_OK; @@ -3138,7 +3147,7 @@ static struct pernet_operations ip6_rout static struct notifier_block ip6_route_dev_notifier = { .notifier_call = ip6_route_dev_notify, - .priority = 0, + .priority = ADDRCONF_NOTIFY_PRIORITY - 10, }; void __init ip6_route_init_special_entries(void)