linux/net/netfilter
Florian Westphal db29a9508a netfilter: conntrack: disable generic tracking for known protocols
Given following iptables ruleset:

-P FORWARD DROP
-A FORWARD -m sctp --dport 9 -j ACCEPT
-A FORWARD -p tcp --dport 80 -j ACCEPT
-A FORWARD -p tcp -m conntrack -m state ESTABLISHED,RELATED -j ACCEPT

One would assume that this allows SCTP on port 9 and TCP on port 80.
Unfortunately, if the SCTP conntrack module is not loaded, this allows
*all* SCTP communication, to pass though, i.e. -p sctp -j ACCEPT,
which we think is a security issue.

This is because on the first SCTP packet on port 9, we create a dummy
"generic l4" conntrack entry without any port information (since
conntrack doesn't know how to extract this information).

All subsequent packets that are unknown will then be in established
state since they will fallback to proto_generic and will match the
'generic' entry.

Our originally proposed version [1] completely disabled generic protocol
tracking, but Jozsef suggests to not track protocols for which a more
suitable helper is available, hence we now mitigate the issue for in
tree known ct protocol helpers only, so that at least NAT and direction
information will still be preserved for others.

 [1] http://www.spinics.net/lists/netfilter-devel/msg33430.html

Joint work with Daniel Borkmann.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-09-29 12:17:49 +02:00
..
ipset netfilter: ipset: hash:mac type added to ipset 2014-09-15 22:20:21 +02:00
ipvs ipvs: Allow heterogeneous pools now that we support them 2014-09-18 08:59:29 +09:00
core.c netfilter: HAVE_JUMP_LABEL instead of CONFIG_JUMP_LABEL 2014-08-25 10:45:28 +02:00
Kconfig Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next 2014-09-10 12:46:32 -07:00
Makefile Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next 2014-09-10 12:46:32 -07:00
nf_conntrack_acct.c netfilter: introduce nf_conn_acct structure 2013-11-03 21:48:49 +01:00
nf_conntrack_amanda.c netfilter: add my copyright statements 2013-04-18 20:27:55 +02:00
nf_conntrack_broadcast.c
nf_conntrack_core.c net: use reciprocal_scale() helper 2014-08-23 12:21:21 -07:00
nf_conntrack_ecache.c netfilter: conntrack: remove timer from ecache extension 2014-06-25 19:15:38 +02:00
nf_conntrack_expect.c net: use reciprocal_scale() helper 2014-08-23 12:21:21 -07:00
nf_conntrack_extend.c netfilter: nf_ct_ext: support variable length extensions 2012-06-16 15:08:49 +02:00
nf_conntrack_ftp.c netfilter: Implement RFC 1123 for FTP conntrack 2013-05-27 13:32:43 +02:00
nf_conntrack_h323_asn1.c
nf_conntrack_h323_main.c netfilter: conntrack: seperate expect locking from nf_conntrack_lock 2014-03-07 11:41:01 +01:00
nf_conntrack_h323_types.c
nf_conntrack_helper.c netfilter: conntrack: remove central spinlock nf_conntrack_lock 2014-03-07 11:41:13 +01:00
nf_conntrack_irc.c netfilter: add my copyright statements 2013-04-18 20:27:55 +02:00
nf_conntrack_l3proto_generic.c
nf_conntrack_labels.c netfilter: connlabels: remove unneeded includes 2013-07-31 16:39:18 +02:00
nf_conntrack_netbios_ns.c
nf_conntrack_netlink.c net: use ktime_get_ns() and ktime_get_real_ns() helpers 2014-08-22 19:57:23 -07:00
nf_conntrack_pptp.c netfilter: nf_conntrack: flush net_gre->keymap_list only from gre helper 2014-04-08 10:56:12 +02:00
nf_conntrack_proto.c netfilter: nf_conntrack: remove dead code 2014-01-03 23:41:37 +01:00
nf_conntrack_proto_dccp.c netfilter: nf_conntrack_dccp: fix skb_header_pointer API usages 2014-01-06 17:40:02 +01:00
nf_conntrack_proto_generic.c netfilter: conntrack: disable generic tracking for known protocols 2014-09-29 12:17:49 +02:00
nf_conntrack_proto_gre.c netfilter: nf_conntrack: flush net_gre->keymap_list only from gre helper 2014-04-08 10:56:12 +02:00
nf_conntrack_proto_sctp.c netfilter: add my copyright statements 2013-04-18 20:27:55 +02:00
nf_conntrack_proto_tcp.c netfilter: add SYNPROXY core/target 2013-08-28 00:27:54 +02:00
nf_conntrack_proto_udp.c netfilter: add my copyright statements 2013-04-18 20:27:55 +02:00
nf_conntrack_proto_udplite.c netfilter: nf_log: prepare net namespace support for loggers 2013-04-05 20:12:54 +02:00
nf_conntrack_sane.c netfilter: nf_ct_helper: better logging for dropped packets 2013-02-19 02:48:05 +01:00
nf_conntrack_seqadj.c netfilter: only warn once on wrong seqadj usage 2014-01-06 14:23:17 +01:00
nf_conntrack_sip.c netfilter: conntrack: seperate expect locking from nf_conntrack_lock 2014-03-07 11:41:01 +01:00
nf_conntrack_snmp.c netfilter: nf_ct_snmp: add include file 2013-01-18 00:28:18 +01:00
nf_conntrack_standalone.c net: use ktime_get_ns() and ktime_get_real_ns() helpers 2014-08-22 19:57:23 -07:00
nf_conntrack_tftp.c netfilter: add my copyright statements 2013-04-18 20:27:55 +02:00
nf_conntrack_timeout.c netfilter: nf_ct_timeout: move initialization out of pernet_operations 2013-01-23 12:56:02 +01:00
nf_conntrack_timestamp.c netfilter: nf_ct_timestamp: Fix BUG_ON after netns deletion 2013-12-20 14:58:29 +01:00
nf_internals.h net: misc: Remove extern from function prototypes 2013-10-19 19:12:11 -04:00
nf_log.c netfilter: bridge: add generic packet logger 2014-06-27 13:20:47 +02:00
nf_log_common.c netfilter: log: split family specific code to nf_log_{ip,ip6,common}.c files 2014-06-27 13:19:59 +02:00
nf_nat_amanda.c netfilter: add my copyright statements 2013-04-18 20:27:55 +02:00
nf_nat_core.c net: use reciprocal_scale() helper 2014-08-23 12:21:21 -07:00
nf_nat_ftp.c netfilter: nf_ct_helper: better logging for dropped packets 2013-02-19 02:48:05 +01:00
nf_nat_helper.c netfilter: nf_conntrack: make sequence number adjustments usuable without NAT 2013-08-28 00:26:48 +02:00
nf_nat_irc.c netfilter: nf_nat: fix access to uninitialized buffer in IRC NAT helper 2014-01-06 14:17:17 +01:00
nf_nat_proto_common.c netfilter: use IS_ENABLED() macro 2014-06-30 11:38:03 +02:00
nf_nat_proto_dccp.c netfilter: use IS_ENABLED() macro 2014-06-30 11:38:03 +02:00
nf_nat_proto_sctp.c netfilter: use IS_ENABLED() macro 2014-06-30 11:38:03 +02:00
nf_nat_proto_tcp.c netfilter: use IS_ENABLED() macro 2014-06-30 11:38:03 +02:00
nf_nat_proto_udp.c netfilter: use IS_ENABLED() macro 2014-06-30 11:38:03 +02:00
nf_nat_proto_udplite.c netfilter: use IS_ENABLED() macro 2014-06-30 11:38:03 +02:00
nf_nat_proto_unknown.c netfilter: add protocol independent NAT core 2012-08-30 03:00:14 +02:00
nf_nat_sip.c netfilter: nf_ct_sip: consolidate NAT hook functions 2013-10-01 12:47:09 +02:00
nf_nat_tftp.c netfilter: nf_ct_helper: better logging for dropped packets 2013-02-19 02:48:05 +01:00
nf_queue.c netfilter: move skb_gso_segment into nfnetlink_queue module 2013-04-29 20:09:05 +02:00
nf_sockopt.c netfilter: don't use mutex_lock_interruptible() 2014-08-08 16:47:23 +02:00
nf_synproxy_core.c netfilter: nf_conntrack: don't release a conntrack with non-zero refcnt 2014-02-05 17:46:06 +01:00
nf_tables_api.c netfilter: nf_tables: store and dump set policy 2014-09-29 11:28:03 +02:00
nf_tables_core.c netfilter: nf_tables: 64bit stats need some extra synchronization 2014-07-14 12:00:17 +02:00
nf_tables_inet.c netfilter: nf_tables: fix error path in the init functions 2014-01-09 23:25:48 +01:00
nfnetlink.c netfilter: nfnetlink: use original skbuff when committing/aborting 2014-09-19 11:14:42 +02:00
nfnetlink_acct.c netfilter: nfnetlink_acct: add filter support to nfacct counter list/reset 2014-08-26 21:36:19 +02:00
nfnetlink_cthelper.c netfilter: check return code from nla_parse_tested 2013-06-20 11:20:13 +02:00
nfnetlink_cttimeout.c netfilter: cttimeout: allow to set/get default protocol timeouts 2013-10-01 13:17:39 +02:00
nfnetlink_log.c netfilter: log: nf_log_packet() as real unified interface 2014-06-27 13:20:13 +02:00
nfnetlink_queue_core.c core, nfqueue, openvswitch: Orphan frags in skb_zerocopy and handle errors 2014-03-27 15:29:38 -04:00
nfnetlink_queue_ct.c netfilter: nf_conntrack: make sequence number adjustments usuable without NAT 2013-08-28 00:26:48 +02:00
nft_bitwise.c netfilter: nf_tables: expression ops overloading 2013-10-14 17:16:08 +02:00
nft_byteorder.c netfilter: nf_tables: expression ops overloading 2013-10-14 17:16:08 +02:00
nft_cmp.c netfilter: nf_tables: fix nft_cmp_fast failure on big endian for size < 4 2014-04-14 10:38:02 +02:00
nft_compat.c netfilter: nft_compat: call {target, match}->destroy() to cleanup entry 2014-06-16 13:08:04 +02:00
nft_counter.c netfilter: nf_tables: expression ops overloading 2013-10-14 17:16:08 +02:00
nft_ct.c netfilter: nft_ct: split nft_ct_init() into two functions for get/set 2014-04-02 21:29:45 +02:00
nft_expr_template.c netfilter: nf_tables: expression ops overloading 2013-10-14 17:16:08 +02:00
nft_exthdr.c netfilter: nft_exthdr: call ipv6_find_hdr() with explicitly initialized offset 2013-12-20 11:25:10 +01:00
nft_hash.c nftables: Convert nft_hash to use generic rhashtable 2014-08-02 19:49:38 -07:00
nft_immediate.c netfilter: nf_tables: restore context for expression destructors 2014-03-08 12:35:17 +01:00
nft_limit.c netfilter: nf_tables: expression ops overloading 2013-10-14 17:16:08 +02:00
nft_log.c netfilter: nft_log: fix coccinelle warnings 2014-06-29 13:55:08 +02:00
nft_lookup.c netfilter: nf_tables: use new transaction infrastructure to handle sets 2014-05-19 12:06:10 +02:00
nft_masq.c netfilter: nf_tables: add new nft_masq expression 2014-09-09 16:31:30 +02:00
nft_meta.c netfilter: nf_tables: add devgroup support in meta expresion 2014-09-09 16:31:23 +02:00
nft_nat.c netfilter: nft_nat: include a flag attribute 2014-09-09 16:31:27 +02:00
nft_payload.c netfilter: nf_tables: check if payload length is a power of 2 2014-02-17 11:21:17 +01:00
nft_queue.c netfilter: nf_tables: fix log/queue expressions for NFPROTO_INET 2014-02-06 11:41:38 +01:00
nft_rbtree.c netfilter: nft_rbtree: introduce locking 2014-06-02 10:54:31 +02:00
nft_reject.c netfilter: nft_reject: split up reject module into IPv4 and IPv6 specifc parts 2014-02-06 09:44:10 +01:00
nft_reject_inet.c netfilter: nft_reject_inet: fix unintended fall-through in switch-statatement 2014-02-14 11:37:33 +01:00
x_tables.c net/netfilter/x_tables.c: use __seq_open_private() 2014-09-26 18:42:29 +02:00
xt_addrtype.c netfilter: xt_addrtype: fix trivial typo 2013-07-31 16:36:25 +02:00
xt_AUDIT.c netfilter: Convert uses of __constant_<foo> to <foo> 2014-03-13 14:13:19 +01:00
xt_bpf.c net: filter: split 'struct sk_filter' into socket and bpf parts 2014-08-02 15:03:58 -07:00
xt_cgroup.c netfilter: x_tables: allow to use default cgroup match 2014-08-19 21:38:55 +02:00
xt_CHECKSUM.c
xt_CLASSIFY.c
xt_cluster.c net: use reciprocal_scale() helper 2014-08-23 12:21:21 -07:00
xt_comment.c
xt_connbytes.c netfilter: Convert pr_warning to pr_warn 2014-09-10 12:40:10 -07:00
xt_connlabel.c netfilter: add connlabel conntrack extension 2013-01-18 00:28:15 +01:00
xt_connlimit.c netfilter: connlimit: move lock array out of struct connlimit_data 2014-04-03 23:52:13 +02:00
xt_connmark.c netfilter: Fix FSF address in file headers 2013-12-06 12:37:57 -05:00
xt_CONNSECMARK.c
xt_conntrack.c netfilter: add my copyright statements 2013-04-18 20:27:55 +02:00
xt_cpu.c
xt_CT.c netfilter: nf_conntrack: don't release a conntrack with non-zero refcnt 2014-02-05 17:46:06 +01:00
xt_dccp.c
xt_devgroup.c
xt_dscp.c
xt_DSCP.c
xt_ecn.c netfilter: xtables: collapse conditions in xt_ecn 2011-12-27 20:45:25 +01:00
xt_esp.c
xt_hashlimit.c netfilter: Convert pr_warning to pr_warn 2014-09-10 12:40:10 -07:00
xt_helper.c
xt_hl.c
xt_HL.c
xt_HMARK.c net: use reciprocal_scale() helper 2014-08-23 12:21:21 -07:00
xt_IDLETIMER.c
xt_ipcomp.c netfilter: xt_ipcomp: Use ntohs to ease sparse warning 2014-02-19 11:41:25 +01:00
xt_iprange.c
xt_ipvs.c ipvs: API change to avoid rescan of IPv6 exthdr 2012-09-28 11:34:33 +09:00
xt_l2tp.c netfilter: introduce l2tp match extension 2014-01-09 21:36:39 +01:00
xt_LED.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2014-08-05 18:46:26 -07:00
xt_length.c
xt_limit.c netfilter: add my copyright statements 2013-04-18 20:27:55 +02:00
xt_LOG.c netfilter: xt_LOG: add missing string format in nf_log_packet() 2014-06-28 18:50:35 +02:00
xt_mac.c netfilter: Convert compare_ether_addr to ether_addr_equal 2012-05-09 20:49:18 -04:00
xt_mark.c
xt_multiport.c
xt_nat.c netfilter: xt_nat: fix incorrect hooks for SNAT and DNAT targets 2012-10-15 13:39:12 +02:00
xt_NETMAP.c netfilter: combine ipt_NETMAP and ip6t_NETMAP 2012-09-21 12:11:08 +02:00
xt_nfacct.c netfilter: nfnetlink_acct: Adding quota support to accounting framework 2014-04-29 18:25:14 +02:00
xt_NFLOG.c netfilter: log: netns NULL ptr bug when calling from conntrack 2013-05-15 14:11:07 +02:00
xt_NFQUEUE.c netfilter: xt_NFQUEUE: separate reusable code 2013-12-07 23:20:45 +01:00
xt_osf.c netfilter: Add {ipt,ip6t}_osf aliases for xt_osf 2014-04-03 23:52:22 +02:00
xt_owner.c userns: xt_owner: Add basic user namespace support. 2012-08-14 21:55:30 -07:00
xt_physdev.c
xt_pkttype.c
xt_policy.c
xt_quota.c
xt_RATEEST.c Revert "netfilter: avoid get_random_bytes calls" 2014-01-06 14:00:55 +01:00
xt_rateest.c net_sched: add 64bit rate estimators 2013-06-11 02:51:03 -07:00
xt_realm.c
xt_recent.c net: use the new API kvfree() 2014-06-05 00:49:51 -07:00
xt_REDIRECT.c netfilter: combine ipt_REDIRECT and ip6t_REDIRECT 2012-09-21 12:12:05 +02:00
xt_repldata.h net: netfilter: LLVMLinux: vlais-netfilter 2014-06-07 11:44:39 -07:00
xt_sctp.c
xt_SECMARK.c
xt_set.c netfilter: ipset: Add skbinfo extension support to SET target. 2014-09-15 22:20:21 +02:00
xt_socket.c netfilter: xt_socket: use sock_gen_put() 2013-10-17 10:27:25 +02:00
xt_state.c
xt_statistic.c net: replace macros net_random and net_srandom with direct calls to prandom 2014-01-14 15:15:25 -08:00
xt_string.c netfilter: xt_string: Remove unnecessary initialization of struct ts_state 2014-09-09 16:31:25 +02:00
xt_TCPMSS.c netfilter: xt_TCPMSS: lookup route from proper net namespace 2013-09-27 16:18:23 +02:00
xt_tcpmss.c
xt_TCPOPTSTRIP.c netfilter: xt_TCPOPTSTRIP: fix possible off by one access 2013-08-01 11:45:15 +02:00
xt_tcpudp.c
xt_TEE.c net: pass info struct via netdevice notifier 2013-05-28 13:11:01 -07:00
xt_time.c netfilter: xt_time: add support to ignore day transition 2012-09-24 14:29:01 +02:00
xt_TPROXY.c ipv6: make lookups simpler and faster 2013-10-09 00:01:25 -04:00
xt_TRACE.c
xt_u32.c