![Pablo Neira Ayuso](/assets/img/avatar_default.png)
Users cannot forge malformed IPv4/IPv6 headers via raw sockets that they
can inject into the stack. Specifically, not for IPv4 since 55888dfb6b
("AF_RAW: Augment raw_send_hdrinc to expand skb to fit iphdr->ihl
(v2)"). IPv6 raw sockets also ensure that packets have a well-formed
IPv6 header available in the skbuff.
At quick glance, br_netfilter also validates layer 3 headers and it
drops malformed both IPv4 and IPv6 packets.
Therefore, let's remove this defensive check all over the place.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
112 lines
2.8 KiB
C
112 lines
2.8 KiB
C
/*
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* "security" table
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*
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* This is for use by Mandatory Access Control (MAC) security models,
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* which need to be able to manage security policy in separate context
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* to DAC.
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*
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* Based on iptable_mangle.c
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*
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* Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
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* Copyright (C) 2000-2004 Netfilter Core Team <coreteam <at> netfilter.org>
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* Copyright (C) 2008 Red Hat, Inc., James Morris <jmorris <at> redhat.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/module.h>
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#include <linux/netfilter_ipv4/ip_tables.h>
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#include <linux/slab.h>
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#include <net/ip.h>
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("James Morris <jmorris <at> redhat.com>");
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MODULE_DESCRIPTION("iptables security table, for MAC rules");
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#define SECURITY_VALID_HOOKS (1 << NF_INET_LOCAL_IN) | \
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(1 << NF_INET_FORWARD) | \
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(1 << NF_INET_LOCAL_OUT)
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static int __net_init iptable_security_table_init(struct net *net);
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static const struct xt_table security_table = {
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.name = "security",
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.valid_hooks = SECURITY_VALID_HOOKS,
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.me = THIS_MODULE,
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.af = NFPROTO_IPV4,
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.priority = NF_IP_PRI_SECURITY,
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.table_init = iptable_security_table_init,
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};
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static unsigned int
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iptable_security_hook(void *priv, struct sk_buff *skb,
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const struct nf_hook_state *state)
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{
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return ipt_do_table(skb, state, state->net->ipv4.iptable_security);
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}
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static struct nf_hook_ops *sectbl_ops __read_mostly;
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static int __net_init iptable_security_table_init(struct net *net)
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{
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struct ipt_replace *repl;
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int ret;
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if (net->ipv4.iptable_security)
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return 0;
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repl = ipt_alloc_initial_table(&security_table);
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if (repl == NULL)
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return -ENOMEM;
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ret = ipt_register_table(net, &security_table, repl, sectbl_ops,
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&net->ipv4.iptable_security);
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kfree(repl);
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return ret;
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}
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static void __net_exit iptable_security_net_exit(struct net *net)
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{
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if (!net->ipv4.iptable_security)
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return;
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ipt_unregister_table(net, net->ipv4.iptable_security, sectbl_ops);
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net->ipv4.iptable_security = NULL;
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}
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static struct pernet_operations iptable_security_net_ops = {
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.exit = iptable_security_net_exit,
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};
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static int __init iptable_security_init(void)
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{
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int ret;
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sectbl_ops = xt_hook_ops_alloc(&security_table, iptable_security_hook);
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if (IS_ERR(sectbl_ops))
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return PTR_ERR(sectbl_ops);
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ret = register_pernet_subsys(&iptable_security_net_ops);
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if (ret < 0) {
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kfree(sectbl_ops);
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return ret;
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}
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ret = iptable_security_table_init(&init_net);
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if (ret) {
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unregister_pernet_subsys(&iptable_security_net_ops);
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kfree(sectbl_ops);
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}
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return ret;
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}
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static void __exit iptable_security_fini(void)
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{
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unregister_pernet_subsys(&iptable_security_net_ops);
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kfree(sectbl_ops);
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}
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module_init(iptable_security_init);
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module_exit(iptable_security_fini);
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