From 3bfe049807c240344b407e3cfb74544927359817 Mon Sep 17 00:00:00 2001 From: Francesco Ruggeri Date: Sun, 17 May 2015 14:30:31 -0700 Subject: netfilter: nfnetlink_{log,queue}: Register pernet in first place nfnetlink_{log,queue}_init() register the netlink callback nf*_rcv_nl_event before registering the pernet_subsys, but the callback relies on data structures allocated by pernet init functions. When nfnetlink_{log,queue} is loaded, if a netlink message is received after the netlink callback is registered but before the pernet_subsys is registered, the kernel will panic in the sequence nfulnl_rcv_nl_event nfnl_log_pernet net_generic BUG_ON(id == 0) where id is nfnl_log_net_id. The panic can be easily reproduced in 4.0.3 by: while true ;do modprobe nfnetlink_log ; rmmod nfnetlink_log ; done & while true ;do ip netns add dummy ; ip netns del dummy ; done & This patch moves register_pernet_subsys to earlier in nfnetlink_log_init. Notice that the BUG_ON hit in 4.0.3 was recently removed in 2591ffd308 ["netns: remove BUG_ONs from net_generic()"]. Signed-off-by: Francesco Ruggeri Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nfnetlink_log.c | 19 ++++++++++--------- net/netfilter/nfnetlink_queue_core.c | 18 +++++++++--------- 2 files changed, 19 insertions(+), 18 deletions(-) (limited to 'net') diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c index 3ad91266c821..4ef1fae8445e 100644 --- a/net/netfilter/nfnetlink_log.c +++ b/net/netfilter/nfnetlink_log.c @@ -1073,7 +1073,13 @@ static struct pernet_operations nfnl_log_net_ops = { static int __init nfnetlink_log_init(void) { - int status = -ENOMEM; + int status; + + status = register_pernet_subsys(&nfnl_log_net_ops); + if (status < 0) { + pr_err("failed to register pernet ops\n"); + goto out; + } netlink_register_notifier(&nfulnl_rtnl_notifier); status = nfnetlink_subsys_register(&nfulnl_subsys); @@ -1088,28 +1094,23 @@ static int __init nfnetlink_log_init(void) goto cleanup_subsys; } - status = register_pernet_subsys(&nfnl_log_net_ops); - if (status < 0) { - pr_err("failed to register pernet ops\n"); - goto cleanup_logger; - } return status; -cleanup_logger: - nf_log_unregister(&nfulnl_logger); cleanup_subsys: nfnetlink_subsys_unregister(&nfulnl_subsys); cleanup_netlink_notifier: netlink_unregister_notifier(&nfulnl_rtnl_notifier); + unregister_pernet_subsys(&nfnl_log_net_ops); +out: return status; } static void __exit nfnetlink_log_fini(void) { - unregister_pernet_subsys(&nfnl_log_net_ops); nf_log_unregister(&nfulnl_logger); nfnetlink_subsys_unregister(&nfulnl_subsys); netlink_unregister_notifier(&nfulnl_rtnl_notifier); + unregister_pernet_subsys(&nfnl_log_net_ops); } MODULE_DESCRIPTION("netfilter userspace logging"); diff --git a/net/netfilter/nfnetlink_queue_core.c b/net/netfilter/nfnetlink_queue_core.c index 0b98c7420239..11c7682fa0ea 100644 --- a/net/netfilter/nfnetlink_queue_core.c +++ b/net/netfilter/nfnetlink_queue_core.c @@ -1317,7 +1317,13 @@ static struct pernet_operations nfnl_queue_net_ops = { static int __init nfnetlink_queue_init(void) { - int status = -ENOMEM; + int status; + + status = register_pernet_subsys(&nfnl_queue_net_ops); + if (status < 0) { + pr_err("nf_queue: failed to register pernet ops\n"); + goto out; + } netlink_register_notifier(&nfqnl_rtnl_notifier); status = nfnetlink_subsys_register(&nfqnl_subsys); @@ -1326,19 +1332,13 @@ static int __init nfnetlink_queue_init(void) goto cleanup_netlink_notifier; } - status = register_pernet_subsys(&nfnl_queue_net_ops); - if (status < 0) { - pr_err("nf_queue: failed to register pernet ops\n"); - goto cleanup_subsys; - } register_netdevice_notifier(&nfqnl_dev_notifier); nf_register_queue_handler(&nfqh); return status; -cleanup_subsys: - nfnetlink_subsys_unregister(&nfqnl_subsys); cleanup_netlink_notifier: netlink_unregister_notifier(&nfqnl_rtnl_notifier); +out: return status; } @@ -1346,9 +1346,9 @@ static void __exit nfnetlink_queue_fini(void) { nf_unregister_queue_handler(); unregister_netdevice_notifier(&nfqnl_dev_notifier); - unregister_pernet_subsys(&nfnl_queue_net_ops); nfnetlink_subsys_unregister(&nfqnl_subsys); netlink_unregister_notifier(&nfqnl_rtnl_notifier); + unregister_pernet_subsys(&nfnl_queue_net_ops); rcu_barrier(); /* Wait for completion of call_rcu()'s */ } -- cgit v1.2.3-59-g8ed1b From 1086bbe97a074844188c6c988fa0b1a98c3ccbb9 Mon Sep 17 00:00:00 2001 From: Dave Jones Date: Tue, 19 May 2015 20:55:17 -0400 Subject: netfilter: ensure number of counters is >0 in do_replace() After improving setsockopt() coverage in trinity, I started triggering vmalloc failures pretty reliably from this code path: warn_alloc_failed+0xe9/0x140 __vmalloc_node_range+0x1be/0x270 vzalloc+0x4b/0x50 __do_replace+0x52/0x260 [ip_tables] do_ipt_set_ctl+0x15d/0x1d0 [ip_tables] nf_setsockopt+0x65/0x90 ip_setsockopt+0x61/0xa0 raw_setsockopt+0x16/0x60 sock_common_setsockopt+0x14/0x20 SyS_setsockopt+0x71/0xd0 It turns out we don't validate that the num_counters field in the struct we pass in from userspace is initialized. The same problem also exists in ebtables, arptables, ipv6, and the compat variants. Signed-off-by: Dave Jones Signed-off-by: Pablo Neira Ayuso --- net/bridge/netfilter/ebtables.c | 4 ++++ net/ipv4/netfilter/arp_tables.c | 6 ++++++ net/ipv4/netfilter/ip_tables.c | 6 ++++++ net/ipv6/netfilter/ip6_tables.c | 6 ++++++ 4 files changed, 22 insertions(+) (limited to 'net') diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c index 91180a7fc943..24c7c96bf5f8 100644 --- a/net/bridge/netfilter/ebtables.c +++ b/net/bridge/netfilter/ebtables.c @@ -1117,6 +1117,8 @@ static int do_replace(struct net *net, const void __user *user, return -ENOMEM; if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter)) return -ENOMEM; + if (tmp.num_counters == 0) + return -EINVAL; tmp.name[sizeof(tmp.name) - 1] = 0; @@ -2159,6 +2161,8 @@ static int compat_copy_ebt_replace_from_user(struct ebt_replace *repl, return -ENOMEM; if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter)) return -ENOMEM; + if (tmp.num_counters == 0) + return -EINVAL; memcpy(repl, &tmp, offsetof(struct ebt_replace, hook_entry)); diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c index 13bfe84bf3ca..a61200754f4b 100644 --- a/net/ipv4/netfilter/arp_tables.c +++ b/net/ipv4/netfilter/arp_tables.c @@ -1075,6 +1075,9 @@ static int do_replace(struct net *net, const void __user *user, /* overflow check */ if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters)) return -ENOMEM; + if (tmp.num_counters == 0) + return -EINVAL; + tmp.name[sizeof(tmp.name)-1] = 0; newinfo = xt_alloc_table_info(tmp.size); @@ -1499,6 +1502,9 @@ static int compat_do_replace(struct net *net, void __user *user, return -ENOMEM; if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters)) return -ENOMEM; + if (tmp.num_counters == 0) + return -EINVAL; + tmp.name[sizeof(tmp.name)-1] = 0; newinfo = xt_alloc_table_info(tmp.size); diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c index c69db7fa25ee..2d0e265fef6e 100644 --- a/net/ipv4/netfilter/ip_tables.c +++ b/net/ipv4/netfilter/ip_tables.c @@ -1262,6 +1262,9 @@ do_replace(struct net *net, const void __user *user, unsigned int len) /* overflow check */ if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters)) return -ENOMEM; + if (tmp.num_counters == 0) + return -EINVAL; + tmp.name[sizeof(tmp.name)-1] = 0; newinfo = xt_alloc_table_info(tmp.size); @@ -1809,6 +1812,9 @@ compat_do_replace(struct net *net, void __user *user, unsigned int len) return -ENOMEM; if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters)) return -ENOMEM; + if (tmp.num_counters == 0) + return -EINVAL; + tmp.name[sizeof(tmp.name)-1] = 0; newinfo = xt_alloc_table_info(tmp.size); diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c index 1a732a1d3c8e..62f5b0d0bc9b 100644 --- a/net/ipv6/netfilter/ip6_tables.c +++ b/net/ipv6/netfilter/ip6_tables.c @@ -1275,6 +1275,9 @@ do_replace(struct net *net, const void __user *user, unsigned int len) /* overflow check */ if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters)) return -ENOMEM; + if (tmp.num_counters == 0) + return -EINVAL; + tmp.name[sizeof(tmp.name)-1] = 0; newinfo = xt_alloc_table_info(tmp.size); @@ -1822,6 +1825,9 @@ compat_do_replace(struct net *net, void __user *user, unsigned int len) return -ENOMEM; if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters)) return -ENOMEM; + if (tmp.num_counters == 0) + return -EINVAL; + tmp.name[sizeof(tmp.name)-1] = 0; newinfo = xt_alloc_table_info(tmp.size); -- cgit v1.2.3-59-g8ed1b From faecbb45ebefb20260ad4a631e011e93c896cb73 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Wed, 20 May 2015 13:42:25 +0200 Subject: Revert "netfilter: bridge: query conntrack about skb dnat" This reverts commit c055d5b03bb4cb69d349d787c9787c0383abd8b2. There are two issues: 'dnat_took_place' made me think that this is related to -j DNAT/MASQUERADE. But thats only one part of the story. This is also relevant for SNAT when we undo snat translation in reverse/reply direction. Furthermore, I originally wanted to do this mainly to avoid storing ipv6 addresses once we make DNAT/REDIRECT work for ipv6 on bridges. However, I forgot about SNPT/DNPT which is stateless. So we can't escape storing address for ipv6 anyway. Might as well do it for ipv4 too. Reported-and-tested-by: Bernhard Thaler Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- include/linux/skbuff.h | 1 + net/bridge/br_netfilter.c | 27 +++++++++------------------ 2 files changed, 10 insertions(+), 18 deletions(-) (limited to 'net') diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 66e374d62f64..f15154a879c7 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -176,6 +176,7 @@ struct nf_bridge_info { struct net_device *physindev; struct net_device *physoutdev; char neigh_header[8]; + __be32 ipv4_daddr; }; #endif diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c index ab55e2472beb..60ddfbeb47f5 100644 --- a/net/bridge/br_netfilter.c +++ b/net/bridge/br_netfilter.c @@ -37,10 +37,6 @@ #include #include -#if IS_ENABLED(CONFIG_NF_CONNTRACK) -#include -#endif - #include #include "br_private.h" #ifdef CONFIG_SYSCTL @@ -350,24 +346,15 @@ free_skb: return 0; } -static bool dnat_took_place(const struct sk_buff *skb) +static bool daddr_was_changed(const struct sk_buff *skb, + const struct nf_bridge_info *nf_bridge) { -#if IS_ENABLED(CONFIG_NF_CONNTRACK) - enum ip_conntrack_info ctinfo; - struct nf_conn *ct; - - ct = nf_ct_get(skb, &ctinfo); - if (!ct || nf_ct_is_untracked(ct)) - return false; - - return test_bit(IPS_DST_NAT_BIT, &ct->status); -#else - return false; -#endif + return ip_hdr(skb)->daddr != nf_bridge->ipv4_daddr; } /* This requires some explaining. If DNAT has taken place, * we will need to fix up the destination Ethernet address. + * This is also true when SNAT takes place (for the reply direction). * * There are two cases to consider: * 1. The packet was DNAT'ed to a device in the same bridge @@ -421,7 +408,7 @@ static int br_nf_pre_routing_finish(struct sock *sk, struct sk_buff *skb) nf_bridge->pkt_otherhost = false; } nf_bridge->mask ^= BRNF_NF_BRIDGE_PREROUTING; - if (dnat_took_place(skb)) { + if (daddr_was_changed(skb, nf_bridge)) { if ((err = ip_route_input(skb, iph->daddr, iph->saddr, iph->tos, dev))) { struct in_device *in_dev = __in_dev_get_rcu(dev); @@ -632,6 +619,7 @@ static unsigned int br_nf_pre_routing(const struct nf_hook_ops *ops, struct sk_buff *skb, const struct nf_hook_state *state) { + struct nf_bridge_info *nf_bridge; struct net_bridge_port *p; struct net_bridge *br; __u32 len = nf_bridge_encap_header_len(skb); @@ -669,6 +657,9 @@ static unsigned int br_nf_pre_routing(const struct nf_hook_ops *ops, if (!setup_pre_routing(skb)) return NF_DROP; + nf_bridge = nf_bridge_info_get(skb); + nf_bridge->ipv4_daddr = ip_hdr(skb)->daddr; + skb->protocol = htons(ETH_P_IP); NF_HOOK(NFPROTO_IPV4, NF_INET_PRE_ROUTING, state->sk, skb, -- cgit v1.2.3-59-g8ed1b