linux/net/netfilter
Daniel Borkmann f9810d5654 netlink, mmap: fix edge-case leakages in nf queue zero-copy
commit 6bb0fef489 upstream.

When netlink mmap on receive side is the consumer of nf queue data,
it can happen that in some edge cases, we write skb shared info into
the user space mmap buffer:

Assume a possible rx ring frame size of only 4096, and the network skb,
which is being zero-copied into the netlink skb, contains page frags
with an overall skb->len larger than the linear part of the netlink
skb.

skb_zerocopy(), which is generic and thus not aware of the fact that
shared info cannot be accessed for such skbs then tries to write and
fill frags, thus leaking kernel data/pointers and in some corner cases
possibly writing out of bounds of the mmap area (when filling the
last slot in the ring buffer this way).

I.e. the ring buffer slot is then of status NL_MMAP_STATUS_VALID, has
an advertised length larger than 4096, where the linear part is visible
at the slot beginning, and the leaked sizeof(struct skb_shared_info)
has been written to the beginning of the next slot (also corrupting
the struct nl_mmap_hdr slot header incl. status etc), since skb->end
points to skb->data + ring->frame_size - NL_MMAP_HDRLEN.

The fix adds and lets __netlink_alloc_skb() take the actual needed
linear room for the network skb + meta data into account. It's completely
irrelevant for non-mmaped netlink sockets, but in case mmap sockets
are used, it can be decided whether the available skb_tailroom() is
really large enough for the buffer, or whether it needs to internally
fallback to a normal alloc_skb().

>From nf queue side, the information whether the destination port is
an mmap RX ring is not really available without extra port-to-socket
lookup, thus it can only be determined in lower layers i.e. when
__netlink_alloc_skb() is called that checks internally for this. I
chose to add the extra ldiff parameter as mmap will then still work:
We have data_len and hlen in nfqnl_build_packet_message(), data_len
is the full length (capped at queue->copy_range) for skb_zerocopy()
and hlen some possible part of data_len that needs to be copied; the
rem_len variable indicates the needed remaining linear mmap space.

The only other workaround in nf queue internally would be after
allocation time by f.e. cap'ing the data_len to the skb_tailroom()
iff we deal with an mmap skb, but that would 1) expose the fact that
we use a mmap skb to upper layers, and 2) trim the skb where we
otherwise could just have moved the full skb into the normal receive
queue.

After the patch, in my test case the ring slot doesn't fit and therefore
shows NL_MMAP_STATUS_COPY, where a full skb carries all the data and
thus needs to be picked up via recv().

Fixes: 3ab1f683bf ("nfnetlink: add support for memory mapped netlink")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
History 2015-09-30 13:20:51 +01:00
..
ipset netfilter: ipset: small potential read beyond the end of buffer 2015-01-16 14:34:49 +00:00
ipvs ipvs: fix crash with sync protocol v0 and FTP 2015-08-25 10:13:49 +01:00
core.c netfilter: nf_qeueue: Drop queue entries on nf_unregister_hook 2015-07-15 10:00:49 +01:00
Kconfig netfilter: nf_tables: add reject module for NFPROTO_INET 2014-02-06 09:44:18 +01:00
Makefile netfilter: nf_tables: add reject module for NFPROTO_INET 2014-02-06 09:44:18 +01:00
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 netfilter: nf_conntrack: nf_conntrack snmp helper 2011-01-18 18:12:24 +01:00
nf_conntrack_core.c arch: Mass conversion of smp_mb__*() 2014-04-18 14:20:48 +02:00
nf_conntrack_ecache.c netfilter: add my copyright statements 2013-04-18 20:27:55 +02:00
nf_conntrack_expect.c netfilter: nf_conntrack: Support expectations in different zones 2015-08-25 10:13:49 +01:00
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 netfilter: h323: bug in parsing of ASN1 SEQOF field 2011-04-04 15:21:02 +02:00
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 [NETFILTER]: nf_conntrack_h323: constify and annotate H.323 helper 2008-01-31 19:28:07 -08:00
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 [NETFILTER]: nf_conntrack: use bool type in struct nf_conntrack_l3proto 2008-04-14 11:15:52 +02:00
nf_conntrack_labels.c netfilter: connlabels: remove unneeded includes 2013-07-31 16:39:18 +02:00
nf_conntrack_netbios_ns.c netfilter: nf_conntrack: nf_conntrack snmp helper 2011-01-18 18:12:24 +01:00
nf_conntrack_netlink.c netfilter: ctnetlink: put back references to master ct and expect objects 2015-08-25 10:13:47 +01:00
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 2015-01-20 10:28:59 +00:00
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: Convert uses of typedef ctl_table to struct ctl_table 2013-06-13 02:36:09 -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 netfilter: nf_qeueue: Drop queue entries on nf_unregister_hook 2015-07-15 10:00:49 +01:00
nf_log.c net: Convert uses of typedef ctl_table to struct ctl_table 2013-06-13 02:36:09 -07:00
nf_nat_amanda.c netfilter: add my copyright statements 2013-04-18 20:27:55 +02:00
nf_nat_core.c netfilter: nf_nat: fix oops on netns removal 2014-06-16 13:58:54 +02:00
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: nf_nat: add full port randomization support 2014-01-03 23:41:26 +01:00
nf_nat_proto_dccp.c netfilter: add protocol independent NAT core 2012-08-30 03:00:14 +02:00
nf_nat_proto_sctp.c net/sctp: Refactor SCTP skb checksum computation 2013-07-27 20:07:15 -07:00
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_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: nf_qeueue: Drop queue entries on nf_unregister_hook 2015-07-15 10:00:49 +01:00
nf_sockopt.c net: Make setsockopt() optlen be unsigned. 2009-09-30 16:12:20 -07:00
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: allow to change chain policy without hook if it exists 2015-05-20 13:26:22 +01:00
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: validate nfnetlink header from batch 2015-02-02 10:01:01 +00:00
nfnetlink_acct.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-06-12 14:27:40 -07:00
nfnetlink_cthelper.c netfilter: nfnetlink_cthelper: Remove 'const' and '&' to avoid warnings 2015-07-20 13:10:31 +01:00
nfnetlink_cttimeout.c netfilter: cttimeout: allow to set/get default protocol timeouts 2013-10-01 13:17:39 +02:00
nfnetlink_log.c netfilter: nf_log: release skbuff on nlmsg put failure 2014-11-14 15:20:04 +00:00
nfnetlink_queue_core.c netlink, mmap: fix edge-case leakages in nf queue zero-copy 2015-09-30 13:20:51 +01:00
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: set IP6T_F_PROTO flag if protocol is set 2015-05-20 13:26:21 +01:00
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 net: use the new API kvfree() 2014-06-05 00:49:51 -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: nf_tables: restore context for expression destructors 2014-03-08 12:35:17 +01:00
nft_lookup.c netfilter: nf_tables: use new transaction infrastructure to handle sets 2014-05-19 12:06:10 +02:00
nft_meta.c netfilter: nf_tables: Make meta expression core functions public 2014-04-23 13:55:30 +02:00
nft_nat.c netfilter: nft_nat: don't dump port information if unset 2014-06-16 13:08:14 +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: fix locking 2015-05-20 13:26:22 +01:00
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 netfilter: x_tables: fix ordering of jumpstack allocation and table update 2013-10-22 10:11:29 +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: let unattached filters use sock_fprog_kern 2014-05-23 16:48:05 -04:00
xt_cgroup.c netfilter: x_tables: allow to use default cgroup match 2014-10-05 13:41:11 -07:00
xt_CHECKSUM.c netfilter: add CHECKSUM target 2010-07-15 17:20:46 +02:00
xt_CLASSIFY.c netfilter: xt_CLASSIFY: add ARP support, allow CLASSIFY target on any table 2010-11-15 13:57:56 +01:00
xt_cluster.c netfilter: nf_conntrack: IPS_UNTRACKED bit 2010-06-08 16:09:52 +02:00
xt_comment.c netfilter: xtables: deconstify struct xt_action_param for matches 2010-05-11 18:33:37 +02:00
xt_connbytes.c netfilter: introduce nf_conn_acct structure 2013-11-03 21:48:49 +01:00
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 netfilter: xtables: substitute temporary defines by final name 2010-05-11 18:31:17 +02:00
xt_conntrack.c netfilter: add my copyright statements 2013-04-18 20:27:55 +02:00
xt_cpu.c netfilter: xtables: add missing aliases for autoloading via iptables 2011-01-18 06:33:54 +01:00
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 netfilter: xtables: change hotdrop pointer to direct modification 2010-05-11 18:35:27 +02:00
xt_devgroup.c netfilter: xtables: add device group match 2011-02-03 00:05:43 +01:00
xt_dscp.c netfilter: xtables: deconstify struct xt_action_param for matches 2010-05-11 18:33:37 +02:00
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 netfilter: xtables: change hotdrop pointer to direct modification 2010-05-11 18:35:27 +02:00
xt_hashlimit.c netfilter: xt_hashlimit: perform garbage collection from process context 2014-10-05 13:41:11 -07:00
xt_helper.c netfilter: xtables: deconstify struct xt_action_param for matches 2010-05-11 18:33:37 +02:00
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_ipcomp.c netfilter: xt_ipcomp: Use ntohs to ease sparse warning 2014-02-19 11:41:25 +01:00
xt_iprange.c Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2011-02-04 14:28:58 -08:00
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 netfilter: xtables: add missing aliases for autoloading via iptables 2011-01-18 06:33:54 +01:00
xt_length.c netfilter: xtables: deconstify struct xt_action_param for matches 2010-05-11 18:33:37 +02:00
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 netfilter: xtables: deconstify struct xt_action_param for matches 2010-05-11 18:33:37 +02:00
xt_multiport.c netfilter: xtables: change hotdrop pointer to direct modification 2010-05-11 18:35:27 +02:00
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 netfilter: xtables: deconstify struct xt_action_param for matches 2010-05-11 18:33:37 +02:00
xt_pkttype.c netfilter: xtables: deconstify struct xt_action_param for matches 2010-05-11 18:33:37 +02:00
xt_policy.c netfilter: xtables: deconstify struct xt_action_param for matches 2010-05-11 18:33:37 +02:00
xt_quota.c net: Fix files explicitly needing to include module.h 2011-10-31 19:30:28 -04:00
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 netfilter: xtables: deconstify struct xt_action_param for matches 2010-05-11 18:33:37 +02:00
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 netfilter: xt_sctp: use WORD_ROUND macro to calculate length of multiple of 4 bytes 2010-06-09 14:47:40 +02:00
xt_SECMARK.c secmark: make secmark object handling generic 2010-10-21 10:12:48 +11:00
xt_set.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2013-11-15 16:47:22 -08:00
xt_socket.c netfilter: xt_socket: fix a stack corruption bug 2015-03-12 15:35:51 +00:00
xt_state.c netfilter: nf_conntrack: IPS_UNTRACKED bit 2010-06-08 16:09:52 +02:00
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: xtables: deconstify struct xt_action_param for matches 2010-05-11 18:33:37 +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 netfilter: xtables: change hotdrop pointer to direct modification 2010-05-11 18:35:27 +02:00
xt_TCPOPTSTRIP.c netfilter: xt_TCPOPTSTRIP: fix possible off by one access 2013-08-01 11:45:15 +02:00
xt_tcpudp.c netfilter: xtables: change hotdrop pointer to direct modification 2010-05-11 18:35:27 +02:00
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 netfilter: xtables: substitute temporary defines by final name 2010-05-11 18:31:17 +02:00
xt_u32.c netfilter: xtables: deconstify struct xt_action_param for matches 2010-05-11 18:33:37 +02:00