![Herbert Xu](/assets/img/avatar_default.png)
When ipcomp_tunnel_attach fails we will call ipcomp_destroy twice. This may lead to double-frees on certain structures. As there is no reason to explicitly call ipcomp_destroy, this patch removes it from ipcomp*.c and lets the standard xfrm_state destruction take place. This is based on the discovery and patch by Alexey Dobriyan. Tested-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
181 lines
4.2 KiB
C
181 lines
4.2 KiB
C
/*
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* IP Payload Compression Protocol (IPComp) - RFC3173.
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*
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* Copyright (c) 2003 James Morris <jmorris@intercode.com.au>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the Free
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* Software Foundation; either version 2 of the License, or (at your option)
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* any later version.
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*
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* Todo:
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* - Tunable compression parameters.
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* - Compression stats.
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* - Adaptive compression.
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*/
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#include <linux/module.h>
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#include <linux/err.h>
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#include <linux/rtnetlink.h>
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#include <net/ip.h>
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#include <net/xfrm.h>
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#include <net/icmp.h>
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#include <net/ipcomp.h>
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#include <net/protocol.h>
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#include <net/sock.h>
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static void ipcomp4_err(struct sk_buff *skb, u32 info)
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{
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__be32 spi;
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struct iphdr *iph = (struct iphdr *)skb->data;
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struct ip_comp_hdr *ipch = (struct ip_comp_hdr *)(skb->data+(iph->ihl<<2));
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struct xfrm_state *x;
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if (icmp_hdr(skb)->type != ICMP_DEST_UNREACH ||
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icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
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return;
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spi = htonl(ntohs(ipch->cpi));
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x = xfrm_state_lookup(&init_net, (xfrm_address_t *)&iph->daddr,
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spi, IPPROTO_COMP, AF_INET);
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if (!x)
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return;
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NETDEBUG(KERN_DEBUG "pmtu discovery on SA IPCOMP/%08x/%pI4\n",
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spi, &iph->daddr);
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xfrm_state_put(x);
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}
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/* We always hold one tunnel user reference to indicate a tunnel */
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static struct xfrm_state *ipcomp_tunnel_create(struct xfrm_state *x)
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{
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struct xfrm_state *t;
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t = xfrm_state_alloc(&init_net);
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if (t == NULL)
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goto out;
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t->id.proto = IPPROTO_IPIP;
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t->id.spi = x->props.saddr.a4;
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t->id.daddr.a4 = x->id.daddr.a4;
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memcpy(&t->sel, &x->sel, sizeof(t->sel));
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t->props.family = AF_INET;
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t->props.mode = x->props.mode;
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t->props.saddr.a4 = x->props.saddr.a4;
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t->props.flags = x->props.flags;
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if (xfrm_init_state(t))
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goto error;
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atomic_set(&t->tunnel_users, 1);
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out:
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return t;
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error:
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t->km.state = XFRM_STATE_DEAD;
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xfrm_state_put(t);
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t = NULL;
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goto out;
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}
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/*
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* Must be protected by xfrm_cfg_mutex. State and tunnel user references are
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* always incremented on success.
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*/
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static int ipcomp_tunnel_attach(struct xfrm_state *x)
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{
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int err = 0;
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struct xfrm_state *t;
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t = xfrm_state_lookup(&init_net, (xfrm_address_t *)&x->id.daddr.a4,
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x->props.saddr.a4, IPPROTO_IPIP, AF_INET);
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if (!t) {
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t = ipcomp_tunnel_create(x);
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if (!t) {
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err = -EINVAL;
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goto out;
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}
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xfrm_state_insert(t);
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xfrm_state_hold(t);
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}
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x->tunnel = t;
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atomic_inc(&t->tunnel_users);
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out:
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return err;
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}
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static int ipcomp4_init_state(struct xfrm_state *x)
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{
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int err = -EINVAL;
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x->props.header_len = 0;
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switch (x->props.mode) {
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case XFRM_MODE_TRANSPORT:
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break;
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case XFRM_MODE_TUNNEL:
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x->props.header_len += sizeof(struct iphdr);
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break;
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default:
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goto out;
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}
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err = ipcomp_init_state(x);
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if (err)
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goto out;
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if (x->props.mode == XFRM_MODE_TUNNEL) {
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err = ipcomp_tunnel_attach(x);
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if (err)
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goto out;
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}
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err = 0;
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out:
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return err;
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}
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static const struct xfrm_type ipcomp_type = {
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.description = "IPCOMP4",
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.owner = THIS_MODULE,
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.proto = IPPROTO_COMP,
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.init_state = ipcomp4_init_state,
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.destructor = ipcomp_destroy,
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.input = ipcomp_input,
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.output = ipcomp_output
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};
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static const struct net_protocol ipcomp4_protocol = {
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.handler = xfrm4_rcv,
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.err_handler = ipcomp4_err,
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.no_policy = 1,
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};
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static int __init ipcomp4_init(void)
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{
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if (xfrm_register_type(&ipcomp_type, AF_INET) < 0) {
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printk(KERN_INFO "ipcomp init: can't add xfrm type\n");
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return -EAGAIN;
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}
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if (inet_add_protocol(&ipcomp4_protocol, IPPROTO_COMP) < 0) {
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printk(KERN_INFO "ipcomp init: can't add protocol\n");
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xfrm_unregister_type(&ipcomp_type, AF_INET);
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return -EAGAIN;
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}
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return 0;
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}
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static void __exit ipcomp4_fini(void)
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{
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if (inet_del_protocol(&ipcomp4_protocol, IPPROTO_COMP) < 0)
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printk(KERN_INFO "ip ipcomp close: can't remove protocol\n");
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if (xfrm_unregister_type(&ipcomp_type, AF_INET) < 0)
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printk(KERN_INFO "ip ipcomp close: can't remove xfrm type\n");
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}
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module_init(ipcomp4_init);
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module_exit(ipcomp4_fini);
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp/IPv4) - RFC3173");
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MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");
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MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_COMP);
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