ipv6: initialize route null entry in addrconf_init()

[ Upstream commit 2f460933f58eee3393aba64f0f6d14acb08d1724 ]

Andrey reported a crash on init_net.ipv6.ip6_null_entry->rt6i_idev
since it is always NULL.

This is clearly wrong, we have code to initialize it to loopback_dev,
unfortunately the order is still not correct.

loopback_dev is registered very early during boot, we lose a chance
to re-initialize it in notifier. addrconf_init() is called after
ip6_route_init(), which means we have no chance to correct it.

Fix it by moving this initialization explicitly after
ipv6_add_dev(init_net.loopback_dev) in addrconf_init().

Reported-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Tested-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h
index 295d291269e2c88ed4930041597a28f7c9a7a2f7..6275d651f76e7c4e126327b3d400cae003c2c4f2 100644 (file)
--- a/include/net/ip6_route.h
+++ b/include/net/ip6_route.h
@@ -77,6 +77,7 @@ static inline struct dst_entry *ip6_route_output(struct net *net,
 struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6,
                                   int flags);
 
+void ip6_route_init_special_entries(void);
 int ip6_route_init(void);
 void ip6_route_cleanup(void);
 

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 253186a3556730b5b22df84fe1645123feee9672..bb747b6cb24193913bd04994e2ca303945273d11 100644 (file)
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -5940,6 +5940,8 @@ int __init addrconf_init(void)
                goto errlo;
        }
 
+       ip6_route_init_special_entries();
+
        for (i = 0; i < IN6_ADDR_HSIZE; i++)
                INIT_HLIST_HEAD(&inet6_addr_lst[i]);
 

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 6c91d5c4a92cec77588758d209c4b4a39625578a..9029b38954e13e0cbf022eaa3bf2d8f6aa13edc9 100644 (file)
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -3681,6 +3681,21 @@ static struct notifier_block ip6_route_dev_notifier = {
        .priority = 0,
 };
 
+void __init ip6_route_init_special_entries(void)
+{
+       /* Registering of the loopback is done before this portion of code,
+        * the loopback reference in rt6_info will not be taken, do it
+        * manually for init_net */
+       init_net.ipv6.ip6_null_entry->dst.dev = init_net.loopback_dev;
+       init_net.ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
+  #ifdef CONFIG_IPV6_MULTIPLE_TABLES
+       init_net.ipv6.ip6_prohibit_entry->dst.dev = init_net.loopback_dev;
+       init_net.ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
+       init_net.ipv6.ip6_blk_hole_entry->dst.dev = init_net.loopback_dev;
+       init_net.ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
+  #endif
+}
+
 int __init ip6_route_init(void)
 {
        int ret;
@@ -3707,17 +3722,6 @@ int __init ip6_route_init(void)
 
        ip6_dst_blackhole_ops.kmem_cachep = ip6_dst_ops_template.kmem_cachep;
 
-       /* Registering of the loopback is done before this portion of code,
-        * the loopback reference in rt6_info will not be taken, do it
-        * manually for init_net */
-       init_net.ipv6.ip6_null_entry->dst.dev = init_net.loopback_dev;
-       init_net.ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
-  #ifdef CONFIG_IPV6_MULTIPLE_TABLES
-       init_net.ipv6.ip6_prohibit_entry->dst.dev = init_net.loopback_dev;
-       init_net.ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
-       init_net.ipv6.ip6_blk_hole_entry->dst.dev = init_net.loopback_dev;
-       init_net.ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
-  #endif
        ret = fib6_init();
        if (ret)
                goto out_register_subsys;