linux/net/netfilter
Daniel Borkmann 7b2252e993 netfilter: nf_nat: fix access to uninitialized buffer in IRC NAT helper
commit 2690d97ade upstream.

Commit 5901b6be88 attempted to introduce IPv6 support into
IRC NAT helper. By doing so, the following code seemed to be removed
by accident:

  ip = ntohl(exp->master->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.ip);
  sprintf(buffer, "%u %u", ip, port);
  pr_debug("nf_nat_irc: inserting '%s' == %pI4, port %u\n", buffer, &ip, port);

This leads to the fact that buffer[] was left uninitialized and
contained some stack value. When we call nf_nat_mangle_tcp_packet(),
we call strlen(buffer) on excatly this uninitialized buffer. If we
are unlucky and the skb has enough tailroom, we overwrite resp. leak
contents with values that sit on our stack into the packet and send
that out to the receiver.

Since the rather informal DCC spec [1] does not seem to specify
IPv6 support right now, we log such occurences so that admins can
act accordingly, and drop the packet. I've looked into XChat source,
and IPv6 is not supported there: addresses are in u32 and print
via %u format string.

Therefore, restore old behaviour as in IPv4, use snprintf(). The
IRC helper does not support IPv6 by now. By this, we can safely use
strlen(buffer) in nf_nat_mangle_tcp_packet() and prevent a buffer
overflow. Also simplify some code as we now have ct variable anyway.

  [1] http://www.irchelp.org/irchelp/rfc/ctcpspec.html

Fixes: 5901b6be88 ("netfilter: nf_nat: support IPv6 in IRC NAT helper")
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Harald Welte <laforge@gnumonks.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-15 15:28:53 -08:00
..
ipset netfilter: ipset: Fix serious failure in CIDR tracking 2013-10-01 09:17:48 -07:00
ipvs netfilter: push reasm skb through instead of original frag skbs 2013-12-08 07:29:25 -08:00
core.c netfilter: add nf_ipv6_ops hook to fix xt_addrtype with IPv6 2013-05-23 11:58:55 +02:00
Kconfig Driver core patches for 3.9-rc1 2013-02-21 12:05:51 -08:00
Makefile netfilter: x_tables: add xt_bpf match 2013-01-21 12:20:19 +01:00
nf_conntrack_acct.c netfilter: nf_ct_acct: move initialization out of pernet_operations 2013-01-23 12:55:29 +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 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2013-05-01 14:08:52 -07:00
nf_conntrack_ecache.c netfilter: add my copyright statements 2013-04-18 20:27:55 +02:00
nf_conntrack_expect.c Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next 2013-04-19 17:55:29 -04:00
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: add my copyright statements 2013-04-18 20:27:55 +02:00
nf_conntrack_h323_asn1.c
nf_conntrack_h323_main.c netfilter: nf_conntrack: fix rt6i_gateway checks for H.323 helper 2013-11-04 04:31:05 -08:00
nf_conntrack_h323_types.c
nf_conntrack_helper.c netfilter: add my copyright statements 2013-04-18 20:27:55 +02:00
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: ctnetlink: send event when conntrack label was modified 2013-06-24 11:32:56 +02:00
nf_conntrack_netbios_ns.c
nf_conntrack_netlink.c netfilter: ctnetlink: send event when conntrack label was modified 2013-06-24 11:32:56 +02:00
nf_conntrack_pptp.c netfilter: add my copyright statements 2013-04-18 20:27:55 +02:00
nf_conntrack_proto_dccp.c netfilter: nf_log: prepare net namespace support for loggers 2013-04-05 20:12:54 +02:00
nf_conntrack_proto_generic.c netfilter: nf_conntrack: generalize nf_ct_l4proto_net 2012-07-04 19:37:22 +02:00
nf_conntrack_proto_gre.c netfilter: add my copyright statements 2013-04-18 20:27:55 +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 my copyright statements 2013-04-18 20:27:55 +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_proto.c netfilter: add my copyright statements 2013-04-18 20:27:55 +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_sip.c netfilter: nf_ct_sip: don't drop packets with offsets pointing outside the packet 2013-04-06 14:03:18 +02:00
nf_conntrack_snmp.c netfilter: nf_ct_snmp: add include file 2013-01-18 00:28:18 +01:00
nf_conntrack_standalone.c netfilter: add my copyright statements 2013-04-18 20:27:55 +02:00
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_tstamp: move initialization out of pernet_operations 2013-01-23 12:55:39 +01:00
nf_internals.h netfilter: pass 'nf_hook_ops' instead of 'list_head' to nf_queue() 2012-09-03 13:52:54 +02:00
nf_log.c netfilter: log: netns NULL ptr bug when calling from conntrack 2013-05-15 14:11:07 +02:00
nf_nat_amanda.c netfilter: add my copyright statements 2013-04-18 20:27:55 +02:00
nf_nat_core.c Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next 2013-04-25 00:53:40 -04:00
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: add my copyright statements 2013-04-18 20:27:55 +02:00
nf_nat_irc.c netfilter: nf_nat: fix access to uninitialized buffer in IRC NAT helper 2014-01-15 15:28:53 -08:00
nf_nat_proto_common.c netfilter: add protocol independent NAT core 2012-08-30 03:00:14 +02:00
nf_nat_proto_dccp.c netfilter: add protocol independent NAT core 2012-08-30 03:00:14 +02:00
nf_nat_proto_sctp.c sctp: Correct type and usage of sctp_end_cksum() 2013-04-29 20:09:08 +02:00
nf_nat_proto_tcp.c netfilter: add protocol independent NAT core 2012-08-30 03:00:14 +02:00
nf_nat_proto_udp.c netfilter: add protocol independent NAT core 2012-08-30 03:00:14 +02:00
nf_nat_proto_udplite.c netfilter: add protocol independent NAT core 2012-08-30 03:00:14 +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_nat_sip: fix mangling 2013-06-24 11:32:40 +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
nf_tproxy_core.c
nfnetlink_acct.c netfilter: nfnetlink_acct: fix incomplete dumping of objects 2013-06-05 12:36:36 +02:00
nfnetlink_cthelper.c hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
nfnetlink_cttimeout.c netfilter: nfnetlink_cttimeout: fix incomplete dumping of objects 2013-06-05 12:36:37 +02:00
nfnetlink_log.c netfilter: log: netns NULL ptr bug when calling from conntrack 2013-05-15 14:11:07 +02:00
nfnetlink_queue_core.c netfilter: nfnetlink_queue: fix missing HW protocol 2013-06-07 18:55:20 +02:00
nfnetlink_queue_ct.c netfilter: nfnetlink_queue: fix sparse warning due to missing include 2012-06-23 02:13:38 +02:00
nfnetlink.c nfnetlink: add support for memory mapped netlink 2013-04-19 14:58:36 -04:00
x_tables.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-05-01 17:51:54 -07:00
xt_addrtype.c netfilter: add nf_ipv6_ops hook to fix xt_addrtype with IPv6 2013-05-23 11:58:55 +02:00
xt_AUDIT.c netfilter: xt_AUDIT: only generate audit log when audit enabled 2013-03-04 14:45:25 +01:00
xt_bpf.c netfilter: x_tables: add xt_bpf match 2013-01-21 12:20:19 +01:00
xt_CHECKSUM.c
xt_CLASSIFY.c
xt_cluster.c
xt_comment.c
xt_connbytes.c Merge branch 'nf-next' of git://1984.lsi.us.es/net-next 2011-12-25 02:21:45 -05:00
xt_connlabel.c netfilter: add connlabel conntrack extension 2013-01-18 00:28:15 +01:00
xt_connlimit.c hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
xt_connmark.c
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: xt_CT: add alias flag 2013-02-05 01:49:26 +01:00
xt_dccp.c
xt_devgroup.c
xt_dscp.c
xt_DSCP.c netfilter: IPv6: fix DSCP mangle code 2011-05-10 10:00:21 +02:00
xt_ecn.c netfilter: xtables: collapse conditions in xt_ecn 2011-12-27 20:45:25 +01:00
xt_esp.c
xt_hashlimit.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-05-01 17:51:54 -07:00
xt_helper.c
xt_hl.c netfilter: Reduce switch/case indent 2011-07-01 16:11:15 -07:00
xt_HL.c netfilter: Reduce switch/case indent 2011-07-01 16:11:15 -07:00
xt_HMARK.c ipv6: Move ipv6_find_hdr() out of Netfilter code. 2012-11-09 17:05:07 -08:00
xt_IDLETIMER.c netfilter: Remove unnecessary OOM logging messages 2011-11-01 09:19:49 +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_LED.c
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: fix mark logging for IPv6 packets 2013-05-29 12:29:18 +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: xtables: add nfacct match to support extended accounting 2011-12-25 02:43:17 +01:00
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: coalesce IPv4 and IPv6 hashing 2013-04-02 01:26:10 +02:00
xt_osf.c netfilter: nf_log: prepare net namespace support for loggers 2013-04-05 20:12:54 +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 net: Fix files explicitly needing to include module.h 2011-10-31 19:30:28 -04:00
xt_rateest.c netfilter: xt_rateest: fix xt_rateest_mt_checkentry() 2011-07-29 16:24:46 +02:00
xt_RATEEST.c hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
xt_realm.c
xt_recent.c proc: Supply PDE attribute setting accessor functions 2013-05-01 17:29:18 -04:00
xt_REDIRECT.c netfilter: combine ipt_REDIRECT and ip6t_REDIRECT 2012-09-21 12:12:05 +02:00
xt_repldata.h
xt_sctp.c
xt_SECMARK.c
xt_set.c netfilter: ipset: set match: add support to match the counters 2013-04-29 20:09:03 +02:00
xt_socket.c netfilter: xt_socket: fix compilation warnings with gcc 4.7 2012-09-03 13:31:39 +02:00
xt_state.c
xt_statistic.c net: Fix files explicitly needing to include module.h 2011-10-31 19:30:28 -04:00
xt_string.c
xt_tcpmss.c
xt_TCPMSS.c netfilter: xt_TCPMSS: Fix missing fragmentation handling 2013-06-12 11:06:19 +02:00
xt_TCPOPTSTRIP.c netfilter: xt_TCPOPTSTRIP: don't use tcp_hdr() 2013-06-11 01:55:07 +02:00
xt_tcpudp.c
xt_TEE.c netfilter: xt_TEE: don't use destination address found in header 2012-10-17 11:00:31 +02:00
xt_time.c netfilter: xt_time: add support to ignore day transition 2012-09-24 14:29:01 +02:00
xt_TPROXY.c net: Fix (nearly-)kernel-doc comments for various functions 2012-07-10 23:13:45 -07:00
xt_TRACE.c
xt_u32.c