From ef6fa3f56c073d7d136f7a318088a030c904f4aa Mon Sep 17 00:00:00 2001 From: Mahesh Bandewar Date: Wed, 19 Jul 2017 15:41:33 -0700 Subject: [PATCH] ipv4: initialize fib_trie prior to register_netdev_notifier call. commit 8799a221f5944a7d74516ecf46d58c28ec1d1f75 upstream. Net stack initialization currently initializes fib-trie after the first call to netdevice_notifier() call. In fact fib_trie initialization needs to happen before first rtnl_register(). It does not cause any problem since there are no devices UP at this moment, but trying to bring 'lo' UP at initialization would make this assumption wrong and exposes the issue. Fixes following crash Call Trace: ? alternate_node_alloc+0x76/0xa0 fib_table_insert+0x1b7/0x4b0 fib_magic.isra.17+0xea/0x120 fib_add_ifaddr+0x7b/0x190 fib_netdev_event+0xc0/0x130 register_netdevice_notifier+0x1c1/0x1d0 ip_fib_init+0x72/0x85 ip_rt_init+0x187/0x1e9 ip_init+0xe/0x1a inet_init+0x171/0x26c ? ipv4_offload_init+0x66/0x66 do_one_initcall+0x43/0x160 kernel_init_freeable+0x191/0x219 ? rest_init+0x80/0x80 kernel_init+0xe/0x150 ret_from_fork+0x22/0x30 Code: f6 46 23 04 74 86 4c 89 f7 e8 ae 45 01 00 49 89 c7 4d 85 ff 0f 85 7b ff ff ff 31 db eb 08 4c 89 ff e8 16 47 01 00 48 8b 44 24 38 <45> 8b 6e 14 4d 63 76 74 48 89 04 24 0f 1f 44 00 00 48 83 c4 08 RIP: kmem_cache_alloc+0xcf/0x1c0 RSP: ffff9b1500017c28 CR2: 0000000000000014 Fixes: 7b1a74fdbb9e ("[NETNS]: Refactor fib initialization so it can handle multiple namespaces.") Fixes: 7f9b80529b8a ("[IPV4]: fib hash|trie initialization") Signed-off-by: Mahesh Bandewar Acked-by: "Eric W. Biederman" Signed-off-by: David S. Miller Signed-off-by: Willy Tarreau --- net/ipv4/fib_frontend.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c index 017b4792cd44..bcd0a05d6002 100644 --- a/net/ipv4/fib_frontend.c +++ b/net/ipv4/fib_frontend.c @@ -1170,13 +1170,14 @@ static struct pernet_operations fib_net_ops = { void __init ip_fib_init(void) { - rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, NULL); - rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, NULL); - rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, NULL); + fib_trie_init(); register_pernet_subsys(&fib_net_ops); + register_netdevice_notifier(&fib_netdev_notifier); register_inetaddr_notifier(&fib_inetaddr_notifier); - fib_trie_init(); + rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, NULL); + rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, NULL); + rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, NULL); } -- 2.20.1