4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: WANG Cong <xiyou.wangcong@xxxxxxxxx>
[ 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@xxxxxxxxxx>
Signed-off-by: Cong Wang <xiyou.wangcong@xxxxxxxxx>
Tested-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
include/net/ip6_route.h | 1 +
net/ipv6/addrconf.c | 2 ++
net/ipv6/route.c | 26 +++++++++++++++-----------
3 files changed, 18 insertions(+), 11 deletions(-)
--- a/include/net/ip6_route.h
+++ b/include/net/ip6_route.h
@@ -77,6 +77,7 @@ static inline struct dst_entry *ip6_rout
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);
--- 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]);
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -3681,6 +3681,21 @@ static struct notifier_block ip6_route_d
.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;