aha/net/netfilter
Florian Westphal 3a0429292d netfilter: xtables: fix conntrack match v1 ipt-save output
commit d6d3f08b0f
(netfilter: xtables: conntrack match revision 2) does break the
v1 conntrack match iptables-save output in a subtle way.

Problem is as follows:

    up = kmalloc(sizeof(*up), GFP_KERNEL);
[..]
   /*
    * The strategy here is to minimize the overhead of v1 matching,
    * by prebuilding a v2 struct and putting the pointer into the
    * v1 dataspace.
    */
    memcpy(up, info, offsetof(typeof(*info), state_mask));
[..]
    *(void **)info  = up;

As the v2 struct pointer is saved in the match data space,
it clobbers the first structure member (->origsrc_addr).

Because the _v1 match function grabs this pointer and does not actually
look at the v1 origsrc, run time functionality does not break.
But iptables -nvL (or iptables-save) cannot know that v1 origsrc_addr
has been overloaded in this way:

$ iptables -p tcp -A OUTPUT -m conntrack --ctorigsrc 10.0.0.1 -j ACCEPT
$ iptables-save
-A OUTPUT -p tcp -m conntrack --ctorigsrc 128.173.134.206 -j ACCEPT

(128.173... is the address to the v2 match structure).

To fix this, we take advantage of the fact that the v1 and v2 structures
are identical with exception of the last two structure members (u8 in v1,
u16 in v2).

We extract them as early as possible and prevent the v2 matching function
from looking at those two members directly.

Previously reported by Michel Messerschmidt via Ben Hutchings, also
see Debian Bug tracker #556587.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2009-11-23 10:43:57 +01:00
..
ipvs sysctl: remove "struct file *" argument of ->proc_handler 2009-09-24 07:21:04 -07:00
core.c netfilter: remove unneeded goto 2009-02-18 16:29:08 +01:00
Kconfig Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6 2009-06-15 03:02:23 -07:00
Makefile netfilter: passive OS fingerprint xtables match 2009-06-08 17:01:51 +02:00
nf_conntrack_acct.c trivial: Fix paramater/parameter typo in dmesg and source comments 2009-06-12 18:01:46 +02:00
nf_conntrack_amanda.c net: replace uses of __constant_{endian} 2009-02-01 00:45:17 -08:00
nf_conntrack_core.c netfilter: nf_conntrack: avoid additional compare. 2009-11-05 14:51:31 +01:00
nf_conntrack_ecache.c netfilter: conntrack: optional reliable conntrack event delivery 2009-06-13 12:30:52 +02:00
nf_conntrack_expect.c nf_conntrack: Use rcu_barrier() 2009-06-25 16:32:52 +02:00
nf_conntrack_extend.c nf_conntrack: Use rcu_barrier() 2009-06-25 16:32:52 +02:00
nf_conntrack_ftp.c netfilter: conntrack: simplify event caching system 2009-06-02 20:08:46 +02:00
nf_conntrack_h323_asn1.c
nf_conntrack_h323_main.c net: replace uses of __constant_{endian} 2009-02-01 00:45:17 -08:00
nf_conntrack_h323_types.c
nf_conntrack_helper.c netfilter: conntrack: move helper destruction to nf_ct_helper_destroy() 2009-06-13 12:28:22 +02:00
nf_conntrack_irc.c netfilter: fix endian bug in conntrack printks 2009-03-28 23:55:57 -07:00
nf_conntrack_l3proto_generic.c
nf_conntrack_netbios_ns.c net: skb->rtable accessor 2009-06-03 02:51:02 -07:00
nf_conntrack_netlink.c netfilter: nfnetlink: constify message attributes and headers 2009-08-25 16:07:58 +02:00
nf_conntrack_pptp.c Merge branch 'master' of /home/davem/src/GIT/linux-2.6/ 2009-03-26 15:23:24 -07:00
nf_conntrack_proto.c netfilter: ctnetlink: add callbacks to the per-proto nlattrs 2009-03-25 18:24:48 +01:00
nf_conntrack_proto_dccp.c Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6 2009-06-11 16:00:49 +02:00
nf_conntrack_proto_generic.c netfilter: change generic l4 protocol number 2009-02-18 16:28:35 +01:00
nf_conntrack_proto_gre.c Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6 2009-06-11 16:00:49 +02:00
nf_conntrack_proto_sctp.c netfilter: nf_conntrack: use per-conntrack locks for protocol data 2009-06-10 14:32:47 +02:00
nf_conntrack_proto_tcp.c netfilter: nf_ct_tcp: improve out-of-sync situation in TCP tracking 2009-11-23 10:37:34 +01:00
nf_conntrack_proto_udp.c netfilter: nf_conntrack: calculate per-protocol nlattr size 2009-03-25 21:53:39 +01:00
nf_conntrack_proto_udplite.c netfilter: nf_ct_dccp/udplite: fix protocol registration error 2009-04-24 15:37:44 +02:00
nf_conntrack_sane.c netfilter: nf_conntrack: connection tracking helper name persistent aliases 2008-11-17 16:01:42 +01:00
nf_conntrack_sip.c netfilter: nf_conntrack: connection tracking helper name persistent aliases 2008-11-17 16:01:42 +01:00
nf_conntrack_standalone.c netfilter: nf_conntrack: use SLAB_DESTROY_BY_RCU and get rid of call_rcu() 2009-03-25 21:05:46 +01:00
nf_conntrack_tftp.c netfilter: nf_conntrack: connection tracking helper name persistent aliases 2008-11-17 16:01:42 +01:00
nf_internals.h netfilter: Use unsigned types for hooknum and pf vars 2008-10-08 11:35:00 +02:00
nf_log.c sysctl: remove "struct file *" argument of ->proc_handler 2009-09-24 07:21:04 -07:00
nf_queue.c netfilter: queue: use NFPROTO_ for queue callsites 2009-05-08 10:30:46 +02:00
nf_sockopt.c net: Make setsockopt() optlen be unsigned. 2009-09-30 16:12:20 -07:00
nf_tproxy_core.c net: Partially allow skb destructors to be used on receive path 2009-02-04 16:55:27 -08:00
nfnetlink.c netfilter: nfnetlink: constify message attributes and headers 2009-08-25 16:07:58 +02:00
nfnetlink_log.c netfilter: remove unneccessary checks from netlink notifiers 2009-11-06 17:04:00 +01:00
nfnetlink_queue.c netfilter: remove unneccessary checks from netlink notifiers 2009-11-06 17:04:00 +01:00
x_tables.c mm: replace various uses of num_physpages by totalram_pages 2009-09-22 07:17:38 -07:00
xt_CLASSIFY.c netfilter: xtables: move extension arguments into compound structure (4/6) 2008-10-08 11:35:19 +02:00
xt_cluster.c netfilter: fix some sparse endianess warnings 2009-06-22 14:15:02 +02:00
xt_comment.c netfilter: xtables: use NFPROTO_UNSPEC in more extensions 2008-10-08 11:35:20 +02:00
xt_connbytes.c netfilter: xtables: cut down on static data for family-independent extensions 2008-10-08 11:35:20 +02:00
xt_connlimit.c netfilter: nf_conntrack: use SLAB_DESTROY_BY_RCU and get rid of call_rcu() 2009-03-25 21:05:46 +01:00
xt_CONNMARK.c netfilter: xtables: remove xt_CONNMARK v0 2009-08-10 12:25:11 +02:00
xt_connmark.c netfilter: xtables: remove xt_connmark v0 2009-08-10 12:25:12 +02:00
xt_CONNSECMARK.c netfilter: xtables: cut down on static data for family-independent extensions 2008-10-08 11:35:20 +02:00
xt_conntrack.c netfilter: xtables: fix conntrack match v1 ipt-save output 2009-11-23 10:43:57 +01:00
xt_dccp.c nf/dccp: merge errorpaths 2008-12-14 23:19:02 -08:00
xt_dscp.c netfilter: xtables: remove xt_TOS v0 2009-08-10 12:25:11 +02:00
xt_DSCP.c netfilter: xtables: remove xt_TOS v0 2009-08-10 12:25:11 +02:00
xt_esp.c netfilter: xtables: move extension arguments into compound structure (2/6) 2008-10-08 11:35:18 +02:00
xt_hashlimit.c mm: replace various uses of num_physpages by totalram_pages 2009-09-22 07:17:38 -07:00
xt_helper.c netfilter: xtables: cut down on static data for family-independent extensions 2008-10-08 11:35:20 +02:00
xt_hl.c netfilter: Combine ipt_ttl and ip6t_hl source 2009-02-18 18:39:31 +01:00
xt_HL.c netfilter: Combine ipt_TTL and ip6t_HL source 2009-02-18 18:38:40 +01:00
xt_iprange.c netfilter: xtables: remove xt_iprange v0 2009-08-10 13:09:44 +02:00
xt_LED.c netfilter: x_tables: add LED trigger target 2009-02-20 10:55:14 +01:00
xt_length.c netfilter: xtables: move extension arguments into compound structure (1/6) 2008-10-08 11:35:18 +02:00
xt_limit.c netfilter: xtables: avoid pointer to self 2009-03-16 15:35:29 +01:00
xt_mac.c netfilter: xtables: use NFPROTO_UNSPEC in more extensions 2008-10-08 11:35:20 +02:00
xt_mark.c netfilter: xtables: remove xt_mark v0 2009-08-10 13:09:45 +02:00
xt_MARK.c netfilter: xtables: remove xt_MARK v0, v1 2009-08-10 12:25:12 +02:00
xt_multiport.c netfilter: xtables: move extension arguments into compound structure (2/6) 2008-10-08 11:35:18 +02:00
xt_NFLOG.c netfilter: xt_NFLOG: don't call nf_log_packet in NFLOG module. 2008-11-04 14:21:08 +01:00
xt_NFQUEUE.c netfilter: fix some sparse endianess warnings 2009-06-22 14:15:02 +02:00
xt_NOTRACK.c netfilter: xtables: use NFPROTO_UNSPEC in more extensions 2008-10-08 11:35:20 +02:00
xt_osf.c netfilter: nfnetlink: constify message attributes and headers 2009-08-25 16:07:58 +02:00
xt_owner.c netfilter: xtables: remove xt_owner v0 2009-08-10 13:32:30 +02:00
xt_physdev.c netfilter: factorize ifname_compare() 2009-03-25 17:31:52 +01:00
xt_pkttype.c netfilter: xtables: cut down on static data for family-independent extensions 2008-10-08 11:35:20 +02:00
xt_policy.c net: skb->dst accessors 2009-06-03 02:51:04 -07:00
xt_quota.c netfilter: xt_quota: fix wrong return value (error case) 2009-08-23 19:09:23 -07:00
xt_rateest.c netfilter: xt_rateest: fix comparison with self 2009-06-22 14:17:12 +02:00
xt_RATEEST.c net: restore gnet_stats_basic to previous definition 2009-08-17 21:33:49 -07:00
xt_realm.c net: skb->dst accessors 2009-06-03 02:51:04 -07:00
xt_recent.c netfilter: xt_recent: fix stack overread in compat code 2009-04-24 17:05:21 +02:00
xt_sctp.c netfilter: xt_sctp: sctp chunk mapping doesn't work 2009-02-09 14:34:56 -08:00
xt_SECMARK.c netfilter: xtables: move extension arguments into compound structure (6/6) 2008-10-08 11:35:19 +02:00
xt_socket.c netfilter: xt_socket: make module available for INPUT chain 2009-10-29 15:35:10 +01:00
xt_state.c netfilter: xtables: move extension arguments into compound structure (3/6) 2008-10-08 11:35:19 +02:00
xt_statistic.c netfilter: xtables: avoid pointer to self 2009-03-16 15:35:29 +01:00
xt_string.c netfilter: xtables: move extension arguments into compound structure (3/6) 2008-10-08 11:35:19 +02:00
xt_TCPMSS.c net: skb->dst accessors 2009-06-03 02:51:04 -07:00
xt_tcpmss.c netfilter: xtables: move extension arguments into compound structure (1/6) 2008-10-08 11:35:18 +02:00
xt_TCPOPTSTRIP.c netfilter: xtables: move extension arguments into compound structure (4/6) 2008-10-08 11:35:19 +02:00
xt_tcpudp.c netfilter: xtables: move extension arguments into compound structure (2/6) 2008-10-08 11:35:18 +02:00
xt_time.c netfilter 08/09: xt_time: print timezone for user information 2009-01-12 21:18:36 -08:00
xt_TPROXY.c netfilter: xtables: move extension arguments into compound structure (5/6) 2008-10-08 11:35:19 +02:00
xt_TRACE.c netfilter: xtables: move extension arguments into compound structure (4/6) 2008-10-08 11:35:19 +02:00
xt_u32.c netfilter: xtables: move extension arguments into compound structure (1/6) 2008-10-08 11:35:18 +02:00