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authorThomas Graf <tgraf@suug.ch>2012-06-14 23:00:17 +0000
committerDavid S. Miller <davem@davemloft.net>2012-06-15 15:30:15 -0700
commit2a0c451ade8e1783c5d453948289e4a978d417c9 (patch)
tree136dbbaf024f45200848ec371368668872545a2e
parent0f6efff92524c65fc3ef41c8b936c526580f1db0 (diff)
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ipv6: Prevent access to uninitialized fib_table_hash via /proc/net/ipv6_route
/proc/net/ipv6_route reflects the contents of fib_table_hash. The proc handler is installed in ip6_route_net_init() whereas fib_table_hash is allocated in fib6_net_init() _after_ the proc handler has been installed. This opens up a short time frame to access fib_table_hash with its pants down. fib6_init() as a whole can't be moved to an earlier position as it also registers the rtnetlink message handlers which should be registered at the end. Therefore split it into fib6_init() which is run early and fib6_init_late() to register the rtnetlink message handlers. Signed-off-by: Thomas Graf <tgraf@suug.ch> Reviewed-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/net/ip6_fib.h2
-rw-r--r--net/ipv6/ip6_fib.c18
-rw-r--r--net/ipv6/route.c16
3 files changed, 24 insertions, 12 deletions
diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h
index 0ae759a6c76e..209af13b0336 100644
--- a/include/net/ip6_fib.h
+++ b/include/net/ip6_fib.h
@@ -271,6 +271,8 @@ extern void fib6_run_gc(unsigned long expires,
extern void fib6_gc_cleanup(void);
extern int fib6_init(void);
+extern int fib6_init_late(void);
+extern void fib6_cleanup_late(void);
#ifdef CONFIG_IPV6_MULTIPLE_TABLES
extern int fib6_rules_init(void);
diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index 74c21b924a79..fbd4afff05fa 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -1692,21 +1692,25 @@ int __init fib6_init(void)
ret = register_pernet_subsys(&fib6_net_ops);
if (ret)
goto out_kmem_cache_create;
-
- ret = __rtnl_register(PF_INET6, RTM_GETROUTE, NULL, inet6_dump_fib,
- NULL);
- if (ret)
- goto out_unregister_subsys;
out:
return ret;
-out_unregister_subsys:
- unregister_pernet_subsys(&fib6_net_ops);
out_kmem_cache_create:
kmem_cache_destroy(fib6_node_kmem);
goto out;
}
+int __init fib6_init_late(void)
+{
+ return __rtnl_register(PF_INET6, RTM_GETROUTE, NULL, inet6_dump_fib,
+ NULL);
+}
+
+void fib6_cleanup_late(void)
+{
+ rtnl_unregister(PF_INET6, RTM_GETROUTE);
+}
+
void fib6_gc_cleanup(void)
{
unregister_pernet_subsys(&fib6_net_ops);
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 999a982ad3fd..dc60bf585966 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -3018,10 +3018,14 @@ int __init ip6_route_init(void)
if (ret)
goto out_kmem_cache;
- ret = register_pernet_subsys(&ip6_route_net_ops);
+ ret = fib6_init();
if (ret)
goto out_dst_entries;
+ ret = register_pernet_subsys(&ip6_route_net_ops);
+ if (ret)
+ goto out_fib6_init;
+
ip6_dst_blackhole_ops.kmem_cachep = ip6_dst_ops_template.kmem_cachep;
/* Registering of the loopback is done before this portion of code,
@@ -3035,13 +3039,13 @@ int __init ip6_route_init(void)
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();
+ ret = fib6_init_late();
if (ret)
goto out_register_subsys;
ret = xfrm6_init();
if (ret)
- goto out_fib6_init;
+ goto out_fib6_init_late;
ret = fib6_rules_init();
if (ret)
@@ -3064,10 +3068,12 @@ fib6_rules_init:
fib6_rules_cleanup();
xfrm6_init:
xfrm6_fini();
-out_fib6_init:
- fib6_gc_cleanup();
+out_fib6_init_late:
+ fib6_cleanup_late();
out_register_subsys:
unregister_pernet_subsys(&ip6_route_net_ops);
+out_fib6_init:
+ fib6_gc_cleanup();
out_dst_entries:
dst_entries_destroy(&ip6_dst_blackhole_ops);
out_kmem_cache: