linux/net/netfilter
Daniel Borkmann 6bb0fef489 netlink, mmap: fix edge-case leakages in nf queue zero-copy
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>
2015-09-09 21:43:22 -07:00
..
ipset netfilter: ipset: Fixing unnamed union init 2015-08-29 01:02:28 +02:00
ipvs ipvs: add more mcast parameters for the sync daemon 2015-08-21 09:10:11 -07:00
core.c netfilter: nf_conntrack: make nf_ct_zone_dflt built-in 2015-09-02 16:32:56 -07:00
Kconfig netfilter: factor out packet duplication for IPv4/IPv6 2015-08-07 11:49:49 +02:00
Makefile netfilter: nf_tables: add netdev table to filter from ingress 2015-05-26 18:41:23 +02:00
nf_conntrack_acct.c netfilter: Remove uses of seq_<foo> return values 2015-03-18 10:51:35 +01:00
nf_conntrack_amanda.c net: Remove state argument from skb_find_text() 2015-02-22 15:59:54 -05:00
nf_conntrack_broadcast.c
nf_conntrack_core.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf 2015-09-05 21:57:42 -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 netfilter: nf_conntrack: add direction support for zones 2015-08-18 01:22:50 +02:00
nf_conntrack_extend.c
nf_conntrack_ftp.c netfilter: replace strnicmp with strncasecmp 2014-10-14 02:18:24 +02:00
nf_conntrack_h323_asn1.c
nf_conntrack_h323_main.c ipv6: Remove external dependency on rt6i_gateway and RTF_ANYCAST 2015-05-25 13:25:33 -04:00
nf_conntrack_h323_types.c
nf_conntrack_helper.c netfilter: fix spelling errors 2014-10-30 17:35:30 +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: Convert print_tuple functions to return void 2014-11-05 14:10:33 -05:00
nf_conntrack_labels.c netfilter: connlabels: Export setting connlabel length 2015-08-27 11:40:43 -07:00
nf_conntrack_netbios_ns.c
nf_conntrack_netlink.c netfilter: nf_conntrack: add efficient mark to zone mapping 2015-08-18 01:24:05 +02:00
nf_conntrack_pptp.c netfilter: nf_conntrack: push zone object into functions 2015-08-11 12:29:01 +02:00
nf_conntrack_proto_dccp.c netfilter: Convert print_tuple functions to return void 2014-11-05 14:10:33 -05:00
nf_conntrack_proto_generic.c netfilter: conntrack: warn the user if there is a better helper to use 2015-06-12 14:06:24 +02:00
nf_conntrack_proto_gre.c netfilter: Convert print_tuple functions to return void 2014-11-05 14:10:33 -05:00
nf_conntrack_proto_sctp.c netfilter: nf_ct_sctp: minimal multihoming support 2015-07-30 12:59:25 +02:00
nf_conntrack_proto_tcp.c conntrack: RFC5961 challenge ACK confuse conntrack LAST-ACK transition 2015-05-15 20:50:56 +02:00
nf_conntrack_proto_udp.c netfilter: Convert print_tuple functions to return void 2014-11-05 14:10:33 -05:00
nf_conntrack_proto_udplite.c netfilter: Convert print_tuple functions to return void 2014-11-05 14:10:33 -05:00
nf_conntrack_proto.c netfilter: nf_conntrack: remove dead code 2014-01-03 23:41:37 +01:00
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 net: Change pseudohdr argument of inet_proto_csum_replace* to be a bool 2015-08-17 21:33:06 -07:00
nf_conntrack_sip.c netfilter: replace strnicmp with strncasecmp 2014-10-14 02:18:24 +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: nf_conntrack: add direction support for zones 2015-08-18 01:22:50 +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_timestamp: Fix BUG_ON after netns deletion 2013-12-20 14:58:29 +01:00
nf_internals.h netfilter: nf_queue: fix nf_queue_nf_hook_drop() 2015-07-23 16:17:58 +02:00
nf_log_common.c netfilter: bridge: add helpers for fetching physin/outdev 2015-04-08 16:49:08 +02:00
nf_log.c netfilter: restore rule tracing via nfnetlink_log 2015-03-19 11:14:48 +01:00
nf_nat_amanda.c netfilter: add my copyright statements 2013-04-18 20:27:55 +02:00
nf_nat_core.c netfilter: nf_conntrack: add direction support for zones 2015-08-18 01:22:50 +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: use IS_ENABLED() macro 2014-06-30 11:38:03 +02:00
nf_nat_proto_dccp.c net: Change pseudohdr argument of inet_proto_csum_replace* to be a bool 2015-08-17 21:33:06 -07:00
nf_nat_proto_sctp.c netfilter: use IS_ENABLED() macro 2014-06-30 11:38:03 +02:00
nf_nat_proto_tcp.c net: Change pseudohdr argument of inet_proto_csum_replace* to be a bool 2015-08-17 21:33:06 -07:00
nf_nat_proto_udp.c net: Change pseudohdr argument of inet_proto_csum_replace* to be a bool 2015-08-17 21:33:06 -07:00
nf_nat_proto_udplite.c net: Change pseudohdr argument of inet_proto_csum_replace* to be a bool 2015-08-17 21:33:06 -07:00
nf_nat_proto_unknown.c netfilter: add protocol independent NAT core 2012-08-30 03:00:14 +02:00
nf_nat_redirect.c netfilter: combine IPv4 and IPv6 nf_nat_redirect code in one module 2014-11-27 13:08:42 +01:00
nf_nat_sip.c netfilter: replace strnicmp with strncasecmp 2014-10-14 02:18:24 +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_queue: fix nf_queue_nf_hook_drop() 2015-07-23 16:17:58 +02:00
nf_sockopt.c netfilter: don't use mutex_lock_interruptible() 2014-08-08 16:47:23 +02:00
nf_synproxy_core.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf 2015-09-05 21:57:42 -07:00
nf_tables_api.c netfilter: nftables: Only run the nftables chains in the proper netns 2015-07-15 18:17:36 +02:00
nf_tables_core.c netfilter: nftables: Only run the nftables chains in the proper netns 2015-07-15 18:17:36 +02:00
nf_tables_inet.c netfilter: nf_tables: fix error path in the init functions 2014-01-09 23:25:48 +01:00
nf_tables_netdev.c netfilter: nf_tables_netdev: unregister hooks on net_device removal 2015-06-15 23:02:35 +02:00
nfnetlink_acct.c netfilter: nfacct: per network namespace support 2015-08-07 11:50:56 +02:00
nfnetlink_cthelper.c netfilter: Zero the tuple in nfnl_cthelper_parse_tuple() 2015-03-12 13:07:36 +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: Kill unused copies of RCV_SKB_FAIL 2015-06-18 21:14:27 +02:00
nfnetlink_queue_core.c netlink, mmap: fix edge-case leakages in nf queue zero-copy 2015-09-09 21:43:22 -07:00
nfnetlink_queue_ct.c netfilter: nf_conntrack: make sequence number adjustments usuable without NAT 2013-08-28 00:26:48 +02:00
nfnetlink.c netfilter: nfnetlink: work around wrong endianess in res_id field 2015-08-29 01:02:35 +02:00
nft_bitwise.c netfilter: nf_tables: support variable sized data in nft_data_init() 2015-04-13 17:17:30 +02:00
nft_byteorder.c netfilter: nf_tables: switch registers to 32 bit addressing 2015-04-13 17:17:29 +02:00
nft_cmp.c netfilter: nf_tables: support variable sized data in nft_data_init() 2015-04-13 17:17:30 +02:00
nft_compat.c netfilter: x_tables: add context to know if extension runs from nft_compat 2015-05-15 20:14:07 +02:00
nft_counter.c netfilter: nft_counter: convert it to use per-cpu counters 2015-08-07 11:49:48 +02:00
nft_ct.c netfilter: nf_tables: switch registers to 32 bit addressing 2015-04-13 17:17:29 +02:00
nft_dynset.c netfilter: nft_dynset: dynamic stateful expression instantiation 2015-04-13 20:19:55 +02:00
nft_exthdr.c netfilter: nf_tables: switch registers to 32 bit addressing 2015-04-13 17:17:29 +02:00
nft_hash.c netfilter: nf_tables: variable sized set element keys / data 2015-04-13 17:17:31 +02:00
nft_immediate.c netfilter: nf_tables: support variable sized data in nft_data_init() 2015-04-13 17:17:30 +02:00
nft_limit.c netfilter: nft_limit: add per-byte limiting 2015-08-07 11:50:50 +02:00
nft_log.c netfilter: nf_tables: get rid of NFT_REG_VERDICT usage 2015-04-13 17:17:07 +02:00
nft_lookup.c netfilter: nf_tables: add flag to indicate set contains expressions 2015-04-13 20:12:32 +02:00
nft_masq.c netfilter: nf_tables: validate hooks in NAT expressions 2015-01-19 14:52:39 +01:00
nft_meta.c net: #ifdefify sk_classid member of struct sock 2015-07-21 16:04:30 -07:00
nft_nat.c netfilter: nf_tables: switch registers to 32 bit addressing 2015-04-13 17:17:29 +02:00
nft_payload.c netfilter: nft_payload: work around vlan header stripping 2015-08-19 08:39:53 +02:00
nft_queue.c netfilter: nf_tables: get rid of NFT_REG_VERDICT usage 2015-04-13 17:17:07 +02:00
nft_rbtree.c netfilter: nf_tables: variable sized set element keys / data 2015-04-13 17:17:31 +02:00
nft_redir.c netfilter: nf_tables: add register parsing/dumping helpers 2015-04-13 17:17:28 +02:00
nft_reject_inet.c netfilter; Add some missing default cases to switch statements in nft_reject. 2015-04-27 13:20:34 -04:00
nft_reject.c netfilter; Add some missing default cases to switch statements in nft_reject. 2015-04-27 13:20:34 -04:00
x_tables.c netfilter: add and use jump label for xt_tee 2015-07-15 18:18:06 +02:00
xt_addrtype.c ipv6: Remove external dependency on rt6i_gateway and RTF_ANYCAST 2015-05-25 13:25:33 -04:00
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: fix cgroup matching on non-full sks 2015-04-01 11:26:42 +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: connlabels: Export setting connlabel length 2015-08-27 11:40:43 -07:00
xt_connlimit.c netfilter: nf_conntrack: push zone object into functions 2015-08-11 12:29:01 +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 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf 2015-09-05 21:57:42 -07:00
xt_dccp.c
xt_devgroup.c
xt_dscp.c
xt_DSCP.c netfilter: fix various sparse warnings 2014-11-13 12:14:42 +01:00
xt_ecn.c
xt_esp.c
xt_hashlimit.c netfilter: Remove checks of seq_printf() return values 2014-11-05 14:11:02 -05:00
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 netfilter: IDLETIMER: fix lockdep warning 2015-07-13 17:23:25 +02:00
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
xt_mark.c netfilter: xt_MARK: Add ARP support 2015-05-14 13:00:27 +02:00
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: nfacct: per network namespace support 2015-08-07 11:50:56 +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: xt_osf: Use continue to reduce indentation 2014-12-23 14:20:10 +01:00
xt_owner.c userns: xt_owner: Add basic user namespace support. 2012-08-14 21:55:30 -07:00
xt_physdev.c netfilter: physdev: use helpers 2015-04-08 16:49:09 +02:00
xt_pkttype.c
xt_policy.c
xt_quota.c
xt_rateest.c net_sched: add 64bit rate estimators 2013-06-11 02:51:03 -07:00
xt_RATEEST.c net: sched: make bstats per cpu and estimator RCU safe 2014-09-30 01:02:26 -04:00
xt_realm.c
xt_recent.c netfilter: xt_recent: don't reject rule if new hitcount exceeds table max 2015-02-16 17:00:47 +01:00
xt_REDIRECT.c netfilter: combine IPv4 and IPv6 nf_nat_redirect code in one module 2014-11-27 13:08:42 +01:00
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: Fix coding styles reported by checkpatch.pl 2015-06-14 10:40:18 +02:00
xt_socket.c netfilter: xt_socket: add XT_SOCKET_RESTORESKMARK flag 2015-06-18 13:05:09 +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 net: Remove state argument from skb_find_text() 2015-02-22 15:59:54 -05:00
xt_tcpmss.c
xt_TCPMSS.c net: Change pseudohdr argument of inet_proto_csum_replace* to be a bool 2015-08-17 21:33:06 -07:00
xt_TCPOPTSTRIP.c net: Change pseudohdr argument of inet_proto_csum_replace* to be a bool 2015-08-17 21:33:06 -07:00
xt_tcpudp.c
xt_TEE.c netfilter: xt_TEE: use IS_ENABLED(CONFIG_NF_DUP_IPV6) 2015-08-21 22:08:41 +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 inet: inet_twsk_deschedule factorization 2015-07-09 15:12:20 -07:00
xt_TRACE.c
xt_u32.c