4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: WANG Cong <xiyou.wangcong@xxxxxxxxx>
[ Upstream commit 242d3a49a2a1a71d8eb9f953db1bcaa9d698ce00 ]
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: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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
@@ -20,6 +20,8 @@
#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
@@ -3492,6 +3492,7 @@ 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
@@ -3480,7 +3480,10 @@ 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
@@ -3489,6 +3492,12 @@ 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;
@@ -3795,7 +3804,7 @@ 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)