linux/net
Stefano Brivio 08d56d8a99 sctp: Avoid out-of-bounds reads from address storage
[ Upstream commit ee6c88bb75 ]

inet_diag_msg_sctp{,l}addr_fill() and sctp_get_sctp_info() copy
sizeof(sockaddr_storage) bytes to fill in sockaddr structs used
to export diagnostic information to userspace.

However, the memory allocated to store sockaddr information is
smaller than that and depends on the address family, so we leak
up to 100 uninitialized bytes to userspace. Just use the size of
the source structs instead, in all the three cases this is what
userspace expects. Zero out the remaining memory.

Unused bytes (i.e. when IPv4 addresses are used) in source
structs sctp_sockaddr_entry and sctp_transport are already
cleared by sctp_add_bind_addr() and sctp_transport_new(),
respectively.

Noticed while testing KASAN-enabled kernel with 'ss':

[ 2326.885243] BUG: KASAN: slab-out-of-bounds in inet_sctp_diag_fill+0x42c/0x6c0 [sctp_diag] at addr ffff881be8779800
[ 2326.896800] Read of size 128 by task ss/9527
[ 2326.901564] CPU: 0 PID: 9527 Comm: ss Not tainted 4.11.0-22.el7a.x86_64 #1
[ 2326.909236] Hardware name: Dell Inc. PowerEdge R730/072T6D, BIOS 2.4.3 01/17/2017
[ 2326.917585] Call Trace:
[ 2326.920312]  dump_stack+0x63/0x8d
[ 2326.924014]  kasan_object_err+0x21/0x70
[ 2326.928295]  kasan_report+0x288/0x540
[ 2326.932380]  ? inet_sctp_diag_fill+0x42c/0x6c0 [sctp_diag]
[ 2326.938500]  ? skb_put+0x8b/0xd0
[ 2326.942098]  ? memset+0x31/0x40
[ 2326.945599]  check_memory_region+0x13c/0x1a0
[ 2326.950362]  memcpy+0x23/0x50
[ 2326.953669]  inet_sctp_diag_fill+0x42c/0x6c0 [sctp_diag]
[ 2326.959596]  ? inet_diag_msg_sctpasoc_fill+0x460/0x460 [sctp_diag]
[ 2326.966495]  ? __lock_sock+0x102/0x150
[ 2326.970671]  ? sock_def_wakeup+0x60/0x60
[ 2326.975048]  ? remove_wait_queue+0xc0/0xc0
[ 2326.979619]  sctp_diag_dump+0x44a/0x760 [sctp_diag]
[ 2326.985063]  ? sctp_ep_dump+0x280/0x280 [sctp_diag]
[ 2326.990504]  ? memset+0x31/0x40
[ 2326.994007]  ? mutex_lock+0x12/0x40
[ 2326.997900]  __inet_diag_dump+0x57/0xb0 [inet_diag]
[ 2327.003340]  ? __sys_sendmsg+0x150/0x150
[ 2327.007715]  inet_diag_dump+0x4d/0x80 [inet_diag]
[ 2327.012979]  netlink_dump+0x1e6/0x490
[ 2327.017064]  __netlink_dump_start+0x28e/0x2c0
[ 2327.021924]  inet_diag_handler_cmd+0x189/0x1a0 [inet_diag]
[ 2327.028045]  ? inet_diag_rcv_msg_compat+0x1b0/0x1b0 [inet_diag]
[ 2327.034651]  ? inet_diag_dump_compat+0x190/0x190 [inet_diag]
[ 2327.040965]  ? __netlink_lookup+0x1b9/0x260
[ 2327.045631]  sock_diag_rcv_msg+0x18b/0x1e0
[ 2327.050199]  netlink_rcv_skb+0x14b/0x180
[ 2327.054574]  ? sock_diag_bind+0x60/0x60
[ 2327.058850]  sock_diag_rcv+0x28/0x40
[ 2327.062837]  netlink_unicast+0x2e7/0x3b0
[ 2327.067212]  ? netlink_attachskb+0x330/0x330
[ 2327.071975]  ? kasan_check_write+0x14/0x20
[ 2327.076544]  netlink_sendmsg+0x5be/0x730
[ 2327.080918]  ? netlink_unicast+0x3b0/0x3b0
[ 2327.085486]  ? kasan_check_write+0x14/0x20
[ 2327.090057]  ? selinux_socket_sendmsg+0x24/0x30
[ 2327.095109]  ? netlink_unicast+0x3b0/0x3b0
[ 2327.099678]  sock_sendmsg+0x74/0x80
[ 2327.103567]  ___sys_sendmsg+0x520/0x530
[ 2327.107844]  ? __get_locked_pte+0x178/0x200
[ 2327.112510]  ? copy_msghdr_from_user+0x270/0x270
[ 2327.117660]  ? vm_insert_page+0x360/0x360
[ 2327.122133]  ? vm_insert_pfn_prot+0xb4/0x150
[ 2327.126895]  ? vm_insert_pfn+0x32/0x40
[ 2327.131077]  ? vvar_fault+0x71/0xd0
[ 2327.134968]  ? special_mapping_fault+0x69/0x110
[ 2327.140022]  ? __do_fault+0x42/0x120
[ 2327.144008]  ? __handle_mm_fault+0x1062/0x17a0
[ 2327.148965]  ? __fget_light+0xa7/0xc0
[ 2327.153049]  __sys_sendmsg+0xcb/0x150
[ 2327.157133]  ? __sys_sendmsg+0xcb/0x150
[ 2327.161409]  ? SyS_shutdown+0x140/0x140
[ 2327.165688]  ? exit_to_usermode_loop+0xd0/0xd0
[ 2327.170646]  ? __do_page_fault+0x55d/0x620
[ 2327.175216]  ? __sys_sendmsg+0x150/0x150
[ 2327.179591]  SyS_sendmsg+0x12/0x20
[ 2327.183384]  do_syscall_64+0xe3/0x230
[ 2327.187471]  entry_SYSCALL64_slow_path+0x25/0x25
[ 2327.192622] RIP: 0033:0x7f41d18fa3b0
[ 2327.196608] RSP: 002b:00007ffc3b731218 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[ 2327.205055] RAX: ffffffffffffffda RBX: 00007ffc3b731380 RCX: 00007f41d18fa3b0
[ 2327.213017] RDX: 0000000000000000 RSI: 00007ffc3b731340 RDI: 0000000000000003
[ 2327.220978] RBP: 0000000000000002 R08: 0000000000000004 R09: 0000000000000040
[ 2327.228939] R10: 00007ffc3b730f30 R11: 0000000000000246 R12: 0000000000000003
[ 2327.236901] R13: 00007ffc3b731340 R14: 00007ffc3b7313d0 R15: 0000000000000084
[ 2327.244865] Object at ffff881be87797e0, in cache kmalloc-64 size: 64
[ 2327.251953] Allocated:
[ 2327.254581] PID = 9484
[ 2327.257215]  save_stack_trace+0x1b/0x20
[ 2327.261485]  save_stack+0x46/0xd0
[ 2327.265179]  kasan_kmalloc+0xad/0xe0
[ 2327.269165]  kmem_cache_alloc_trace+0xe6/0x1d0
[ 2327.274138]  sctp_add_bind_addr+0x58/0x180 [sctp]
[ 2327.279400]  sctp_do_bind+0x208/0x310 [sctp]
[ 2327.284176]  sctp_bind+0x61/0xa0 [sctp]
[ 2327.288455]  inet_bind+0x5f/0x3a0
[ 2327.292151]  SYSC_bind+0x1a4/0x1e0
[ 2327.295944]  SyS_bind+0xe/0x10
[ 2327.299349]  do_syscall_64+0xe3/0x230
[ 2327.303433]  return_from_SYSCALL_64+0x0/0x6a
[ 2327.308194] Freed:
[ 2327.310434] PID = 4131
[ 2327.313065]  save_stack_trace+0x1b/0x20
[ 2327.317344]  save_stack+0x46/0xd0
[ 2327.321040]  kasan_slab_free+0x73/0xc0
[ 2327.325220]  kfree+0x96/0x1a0
[ 2327.328530]  dynamic_kobj_release+0x15/0x40
[ 2327.333195]  kobject_release+0x99/0x1e0
[ 2327.337472]  kobject_put+0x38/0x70
[ 2327.341266]  free_notes_attrs+0x66/0x80
[ 2327.345545]  mod_sysfs_teardown+0x1a5/0x270
[ 2327.350211]  free_module+0x20/0x2a0
[ 2327.354099]  SyS_delete_module+0x2cb/0x2f0
[ 2327.358667]  do_syscall_64+0xe3/0x230
[ 2327.362750]  return_from_SYSCALL_64+0x0/0x6a
[ 2327.367510] Memory state around the buggy address:
[ 2327.372855]  ffff881be8779700: fc fc fc fc 00 00 00 00 00 00 00 00 fc fc fc fc
[ 2327.380914]  ffff881be8779780: fb fb fb fb fb fb fb fb fc fc fc fc 00 00 00 00
[ 2327.388972] >ffff881be8779800: 00 00 00 00 fc fc fc fc fb fb fb fb fb fb fb fb
[ 2327.397031]                                ^
[ 2327.401792]  ffff881be8779880: fc fc fc fc fb fb fb fb fb fb fb fb fc fc fc fc
[ 2327.409850]  ffff881be8779900: 00 00 00 00 00 04 fc fc fc fc fc fc 00 00 00 00
[ 2327.417907] ==================================================================

This fixes CVE-2017-7558.

References: https://bugzilla.redhat.com/show_bug.cgi?id=1480266
Fixes: 8f840e47f1 ("sctp: add the sctp_diag.c file")
Cc: Xin Long <lucien.xin@gmail.com>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Reviewed-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
History 2017-09-20 08:19:54 +02:00
..
6lowpan 6lowpan: ndisc: no overreact if no short address is available 2016-09-19 20:19:34 +02:00
9p p9_client_readdir() fix 2017-05-03 08:36:38 -07:00
802 net: Kill dev_rebuild_header 2015-03-02 16:43:41 -05:00
8021q net: 8021q: Fix one possible panic caused by BUG_ON in free_netdev 2017-07-05 14:40:16 +02:00
appletalk appletalk: use IS_ENABLED() instead of checking for built-in or module 2016-09-10 21:19:10 -07:00
atm lec: use IS_ENABLED() instead of checking for built-in or module 2016-09-10 21:19:10 -07:00
ax25 ax25: Fix segfault after sock connection timeout 2017-02-04 09:47:09 +01:00
batman-adv batman-adv: Check for alloc errors when preparing TT local data 2016-12-02 10:46:59 +01:00
bluetooth Bluetooth: Properly check L2CAP config option output buffer length 2017-09-13 14:13:36 -07:00
bridge bridge: mdb: fix leak on complete_info ptr on fail path 2017-07-21 07:42:17 +02:00
caif net: caif: Fix a sleep-in-atomic bug in cfpkt_create_pfx 2017-07-05 14:40:14 +02:00
can can: Fix kernel panic at security_sock_rcv_skb 2017-02-18 15:11:40 +01:00
ceph libceph: force GFP_NOIO for socket allocations 2017-04-08 09:30:30 +02:00
core udp: on peeking bad csum, drop packets even if not at head 2017-09-20 08:19:53 +02:00
dcb net: dcb: set error code on failures 2016-12-03 23:54:25 -05:00
dccp dccp: defer ccid_hc_tx_delete() at dismantle time 2017-08-30 10:21:39 +02:00
decnet decnet: always not take dst->__refcnt when inserting dst into hash table 2017-07-05 14:40:16 +02:00
dns_resolver KEYS: Add a facility to restrict new links into a keyring 2016-04-11 22:37:37 +01:00
dsa net: dsa: Check return value of phy_connect_direct() 2017-07-05 14:40:23 +02:00
ethernet net: introduce device min_header_len 2017-02-18 15:11:43 +01:00
hsr net/hsr: Remove unused but set variable 2016-10-18 10:28:18 -04:00
ieee802154 ieee802154: 6lowpan: fix intra pan id check 2016-07-08 13:23:12 +02:00
ipv4 tcp: when rearming RTO, if RTO time is in past then fire RTO ASAP 2017-08-30 10:21:42 +02:00
ipv6 ipv6: fix sparse warning on rt6i_node 2017-09-20 08:19:53 +02:00
ipx ipx: call ipxitf_put() in ioctl error path 2017-05-25 15:44:41 +02:00
irda irda: do not leak initialized list.dev to userspace 2017-08-30 10:21:42 +02:00
iucv net/af_iucv: don't use paged skbs for TX on HiperSockets 2017-01-19 20:18:04 +01:00
kcm kcm: return immediately after copy_from_user() failure 2017-05-03 08:36:34 -07:00
key af_key: do not use GFP_KERNEL in atomic contexts 2017-08-30 10:21:38 +02:00
l2tp l2tp: consider '::' as wildcard address in l2tp_ip6 socket lookup 2017-08-06 18:59:46 -07:00
l3mdev net: ipv6: Remove l3mdev_get_saddr6 2016-09-10 23:12:53 -07:00
lapb net/lapb: tuse %*ph to dump buffers 2016-05-29 22:33:25 -07:00
llc net/llc: avoid BUG_ON() in skb_orphan() 2017-02-26 11:10:50 +01:00
mac80211 mac80211: initialize SMPS field in HT capabilities 2017-07-05 14:40:25 +02:00
mac802154 mac802154: use rate limited warnings for malformed frames 2016-09-19 20:19:34 +02:00
mpls mpls: Do not decrement alive counter for unregister events 2017-03-22 12:43:34 +01:00
ncsi net/ncsi: Improve HNCDSC AEN handler 2016-10-20 11:23:08 -04:00
netfilter netfilter: nat: fix src map lookup 2017-08-30 10:21:51 +02:00
netlabel netlabel: Implement CALIPSO config functions for SMACK. 2016-06-27 15:06:18 -04:00
netlink netlink: Do not schedule work from sk_destruct 2016-12-05 19:43:42 -05:00
netrom netfilter: Remove spurios included of netfilter.h 2015-06-18 21:14:32 +02:00
nfc NFC: Add sockaddr length checks before accessing sa_family in bind handlers 2017-07-27 15:07:56 -07:00
openvswitch openvswitch: fix skb_panic due to the incorrect actions attrlen 2017-08-30 10:21:40 +02:00
packet packet: fix tp_reserve race in packet_set_ring 2017-08-12 19:31:22 -07:00
phonet sock: struct proto hash function may error 2016-02-11 03:54:14 -05:00
qrtr Merge tag 'qcom-soc-for-4.7-2' into net-next 2016-05-17 14:11:19 -04:00
rds rds: tcp: use sock_create_lite() to create the accept socket 2017-07-21 07:42:19 +02:00
rfkill rfkill: Use switch to demux userspace operations 2016-04-05 10:48:53 +02:00
rose rose: limit sk_filter trim to payload 2016-07-13 11:53:40 -07:00
rxrpc rxrpc: Fix several cases where a padded len isn't checked in ticket decode 2017-06-29 13:00:31 +02:00
sched net: sched: fix NULL pointer dereference when action calls some targets 2017-08-30 10:21:42 +02:00
sctp sctp: Avoid out-of-bounds reads from address storage 2017-09-20 08:19:54 +02:00
strparser strparser: destroy workqueue on module exit 2017-03-22 12:43:33 +01:00
sunrpc net: sunrpc: svcsock: fix NULL-pointer exception 2017-08-30 10:21:51 +02:00
switchdev switchdev: Execute bridge ndos only for bridge ports 2016-10-19 10:58:04 -04:00
tipc tipc: fix use-after-free 2017-08-30 10:21:41 +02:00
unix af_unix: Add sockaddr length checks before accessing sa_family in bind and connect handlers 2017-07-05 14:40:14 +02:00
vmw_vsock vsock/virtio: fix src/dst cid format 2017-01-09 08:32:23 +01:00
wimax net:wimax: Fix doucble word "the the" in networking.xml 2015-08-09 22:43:52 -07:00
wireless cfg80211: Check if NAN service ID is of expected size 2017-07-21 07:42:20 +02:00
x25 net: x25: remove null checks on arrays calling_ae and called_ae 2016-09-09 18:13:30 -07:00
xfrm xfrm: policy: check policy direction value 2017-09-07 08:35:40 +02:00
compat.c packet: compat support for sock_fprog 2016-06-09 23:41:03 -07:00
Kconfig strparser: Stream parser for messages 2016-08-17 19:36:23 -04:00
Makefile strparser: Stream parser for messages 2016-08-17 19:36:23 -04:00
socket.c net: socket: fix recvmmsg not returning error from sock_error 2017-02-26 11:10:51 +01:00
sysctl_net.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2016-10-06 09:52:23 -07:00