ipv6: initialize route null entry in addrconf_init()

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>
This commit is contained in:
WANG Cong 2017-05-03 22:07:31 -07:00 committed by David S. Miller
parent 15981952e8
commit 2f460933f5
3 changed files with 18 additions and 11 deletions

View File

@ -84,6 +84,7 @@ struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6,
struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
int ifindex, struct flowi6 *fl6, int flags);
void ip6_route_init_special_entries(void);
int ip6_route_init(void);
void ip6_route_cleanup(void);

View File

@ -6573,6 +6573,8 @@ 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]);

View File

@ -4027,6 +4027,21 @@ 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;
@ -4053,17 +4068,6 @@ 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;