linux-stable.git/net/netfilter, branch v3.16.61

netfilter: nf_log: don't hold nf_log_mutex during user access

2018-11-20T18:05:28+00:00

commit ce00bf07cc95a57cd20b208e02b3c2604e532ae8 upstream.

The old code would indefinitely block other users of nf_log_mutex if
a userspace access in proc_dostring() blocked e.g. due to a userfaultfd
region. Fix it by moving proc_dostring() out of the locked region.

This is a followup to commit 266d07cb1c9a ("netfilter: nf_log: fix
sleeping function called from invalid context"), which changed this code
from using rcu_read_lock() to taking nf_log_mutex.

Fixes: 266d07cb1c9a ("netfilter: nf_log: fix sleeping function calle[...]")
Signed-off-by: Jann Horn 
Signed-off-by: Pablo Neira Ayuso 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

netfilter: nf_queue: augment nfqa_cfg_policy

2018-11-20T18:05:17+00:00

commit ba062ebb2cd561d404e0fba8ee4b3f5ebce7cbfc upstream.

Three attributes are currently not verified, thus can trigger KMSAN
warnings such as :

BUG: KMSAN: uninit-value in __arch_swab32 arch/x86/include/uapi/asm/swab.h:10 [inline]
BUG: KMSAN: uninit-value in __fswab32 include/uapi/linux/swab.h:59 [inline]
BUG: KMSAN: uninit-value in nfqnl_recv_config+0x939/0x17d0 net/netfilter/nfnetlink_queue.c:1268
CPU: 1 PID: 4521 Comm: syz-executor120 Not tainted 4.17.0+ #5
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x185/0x1d0 lib/dump_stack.c:113
 kmsan_report+0x188/0x2a0 mm/kmsan/kmsan.c:1117
 __msan_warning_32+0x70/0xc0 mm/kmsan/kmsan_instr.c:620
 __arch_swab32 arch/x86/include/uapi/asm/swab.h:10 [inline]
 __fswab32 include/uapi/linux/swab.h:59 [inline]
 nfqnl_recv_config+0x939/0x17d0 net/netfilter/nfnetlink_queue.c:1268
 nfnetlink_rcv_msg+0xb2e/0xc80 net/netfilter/nfnetlink.c:212
 netlink_rcv_skb+0x37e/0x600 net/netlink/af_netlink.c:2448
 nfnetlink_rcv+0x2fe/0x680 net/netfilter/nfnetlink.c:513
 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline]
 netlink_unicast+0x1680/0x1750 net/netlink/af_netlink.c:1336
 netlink_sendmsg+0x104f/0x1350 net/netlink/af_netlink.c:1901
 sock_sendmsg_nosec net/socket.c:629 [inline]
 sock_sendmsg net/socket.c:639 [inline]
 ___sys_sendmsg+0xec8/0x1320 net/socket.c:2117
 __sys_sendmsg net/socket.c:2155 [inline]
 __do_sys_sendmsg net/socket.c:2164 [inline]
 __se_sys_sendmsg net/socket.c:2162 [inline]
 __x64_sys_sendmsg+0x331/0x460 net/socket.c:2162
 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x43fd59
RSP: 002b:00007ffde0e30d28 EFLAGS: 00000213 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 000000000043fd59
RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
R10: 00000000004002c8 R11: 0000000000000213 R12: 0000000000401680
R13: 0000000000401710 R14: 0000000000000000 R15: 0000000000000000

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:279 [inline]
 kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:189
 kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:315
 kmsan_slab_alloc+0x10/0x20 mm/kmsan/kmsan.c:322
 slab_post_alloc_hook mm/slab.h:446 [inline]
 slab_alloc_node mm/slub.c:2753 [inline]
 __kmalloc_node_track_caller+0xb35/0x11b0 mm/slub.c:4395
 __kmalloc_reserve net/core/skbuff.c:138 [inline]
 __alloc_skb+0x2cb/0x9e0 net/core/skbuff.c:206
 alloc_skb include/linux/skbuff.h:988 [inline]
 netlink_alloc_large_skb net/netlink/af_netlink.c:1182 [inline]
 netlink_sendmsg+0x76e/0x1350 net/netlink/af_netlink.c:1876
 sock_sendmsg_nosec net/socket.c:629 [inline]
 sock_sendmsg net/socket.c:639 [inline]
 ___sys_sendmsg+0xec8/0x1320 net/socket.c:2117
 __sys_sendmsg net/socket.c:2155 [inline]
 __do_sys_sendmsg net/socket.c:2164 [inline]
 __se_sys_sendmsg net/socket.c:2162 [inline]
 __x64_sys_sendmsg+0x331/0x460 net/socket.c:2162
 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: fdb694a01f1f ("netfilter: Add fail-open support")
Fixes: 829e17a1a602 ("[NETFILTER]: nfnetlink_queue: allow changing queue length through netlink")
Signed-off-by: Eric Dumazet 
Reported-by: syzbot 
Signed-off-by: Pablo Neira Ayuso 
[bwh: Backported to 3.16: adjust filename]
Signed-off-by: Ben Hutchings

ipvs: fix buffer overflow with sync daemon and service

2018-10-21T07:46:16+00:00

commit 52f96757905bbf0edef47f3ee6c7c784e7f8ff8a upstream.

syzkaller reports for buffer overflow for interface name
when starting sync daemons [1]

What we do is that we copy user structure into larger stack
buffer but later we search NUL past the stack buffer.
The same happens for sched_name when adding/editing virtual server.

We are restricted by IP_VS_SCHEDNAME_MAXLEN and IP_VS_IFNAME_MAXLEN
being used as size in include/uapi/linux/ip_vs.h, so they
include the space for NUL.

As using strlcpy is wrong for unsafe source, replace it with
strscpy and add checks to return EINVAL if source string is not
NUL-terminated. The incomplete strlcpy fix comes from 2.6.13.

For the netlink interface reduce the len parameter for
IPVS_DAEMON_ATTR_MCAST_IFN and IPVS_SVC_ATTR_SCHED_NAME,
so that we get proper EINVAL.

[1]
kernel BUG at lib/string.c:1052!
invalid opcode: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
    (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 373 Comm: syz-executor936 Not tainted 4.17.0-rc4+ #45
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:fortify_panic+0x13/0x20 lib/string.c:1051
RSP: 0018:ffff8801c976f800 EFLAGS: 00010282
RAX: 0000000000000022 RBX: 0000000000000040 RCX: 0000000000000000
RDX: 0000000000000022 RSI: ffffffff8160f6f1 RDI: ffffed00392edef6
RBP: ffff8801c976f800 R08: ffff8801cf4c62c0 R09: ffffed003b5e4fb0
R10: ffffed003b5e4fb0 R11: ffff8801daf27d87 R12: ffff8801c976fa20
R13: ffff8801c976fae4 R14: ffff8801c976fae0 R15: 000000000000048b
FS:  00007fd99f75e700(0000) GS:ffff8801daf00000(0000)
knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000200001c0 CR3: 00000001d6843000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
  strlen include/linux/string.h:270 [inline]
  strlcpy include/linux/string.h:293 [inline]
  do_ip_vs_set_ctl+0x31c/0x1d00 net/netfilter/ipvs/ip_vs_ctl.c:2388
  nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
  nf_setsockopt+0x7d/0xd0 net/netfilter/nf_sockopt.c:115
  ip_setsockopt+0xd8/0xf0 net/ipv4/ip_sockglue.c:1253
  udp_setsockopt+0x62/0xa0 net/ipv4/udp.c:2487
  ipv6_setsockopt+0x149/0x170 net/ipv6/ipv6_sockglue.c:917
  tcp_setsockopt+0x93/0xe0 net/ipv4/tcp.c:3057
  sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:3046
  __sys_setsockopt+0x1bd/0x390 net/socket.c:1903
  __do_sys_setsockopt net/socket.c:1914 [inline]
  __se_sys_setsockopt net/socket.c:1911 [inline]
  __x64_sys_setsockopt+0xbe/0x150 net/socket.c:1911
  do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
  entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x447369
RSP: 002b:00007fd99f75dda8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00000000006e39e4 RCX: 0000000000447369
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200001c0 R11: 0000000000000246 R12: 00000000006e39e0
R13: 75a1ff93f0896195 R14: 6f745f3168746576 R15: 0000000000000001
Code: 08 5b 41 5c 41 5d 41 5e 41 5f 5d c3 0f 0b 48 89 df e8 d2 8f 48 fa eb
de 55 48 89 fe 48 c7 c7 60 65 64 88 48 89 e5 e8 91 dd f3 f9 <0f> 0b 90 90
90 90 90 90 90 90 90 90 90 55 48 89 e5 41 57 41 56
RIP: fortify_panic+0x13/0x20 lib/string.c:1051 RSP: ffff8801c976f800

Reported-and-tested-by: syzbot+aac887f77319868646df@syzkaller.appspotmail.com
Fixes: e4ff67513096 ("ipvs: add sync_maxlen parameter for the sync daemon")
Fixes: 4da62fc70d7c ("[IPVS]: Fix for overflows")
Signed-off-by: Julian Anastasov 
Acked-by: Simon Horman 
Signed-off-by: Pablo Neira Ayuso 
[bwh: Backported to 3.16: Interface name is copied in start_sync_thread(),
 not do_ip_vs_set_ctl()]
Signed-off-by: Ben Hutchings

ipvs: fix stats update from local clients

2018-10-21T07:45:57+00:00

commit d5e032fc5697b6c0d6b4958bcacb981a08f8174e upstream.

Local clients are not properly synchronized on 32-bit CPUs when
updating stats (3.10+). Now it is possible estimation_timer (timer),
a stats reader, to interrupt the local client in the middle of
write_seqcount_{begin,end} sequence leading to loop (DEADLOCK).
The same interrupt can happen from received packet (SoftIRQ)
which updates the same per-CPU stats.

Fix it by disabling BH while updating stats.

Found with debug:

WARNING: inconsistent lock state
4.17.0-rc2-00105-g35cb6d7-dirty #2 Not tainted
--------------------------------
inconsistent {IN-SOFTIRQ-R} -> {SOFTIRQ-ON-W} usage.
ftp/2545 [HC0[0]:SC0[0]:HE1:SE1] takes:
86845479 (&syncp->seq#6){+.+-}, at: ip_vs_schedule+0x1c5/0x59e [ip_vs]
{IN-SOFTIRQ-R} state was registered at:
 lock_acquire+0x44/0x5b
 estimation_timer+0x1b3/0x341 [ip_vs]
 call_timer_fn+0x54/0xcd
 run_timer_softirq+0x10c/0x12b
 __do_softirq+0xc1/0x1a9
 do_softirq_own_stack+0x1d/0x23
 irq_exit+0x4a/0x64
 smp_apic_timer_interrupt+0x63/0x71
 apic_timer_interrupt+0x3a/0x40
 default_idle+0xa/0xc
 arch_cpu_idle+0x9/0xb
 default_idle_call+0x21/0x23
 do_idle+0xa0/0x167
 cpu_startup_entry+0x19/0x1b
 start_secondary+0x133/0x182
 startup_32_smp+0x164/0x168
irq event stamp: 42213

other info that might help us debug this:
Possible unsafe locking scenario:

      CPU0
      ----
 lock(&syncp->seq#6);
 
   lock(&syncp->seq#6);

*** DEADLOCK ***

Fixes: ac69269a45e8 ("ipvs: do not disable bh for long time")
Signed-off-by: Julian Anastasov 
Acked-by: Simon Horman 
Signed-off-by: Pablo Neira Ayuso 
[bwh: Backported to 3.16:
 - Drop change in ip_vs_conn_stats(), which doesn't use a seqlock
 - Adjust context]
Signed-off-by: Ben Hutchings

netfilter: nf_tables: can't fail after linking rule into active rule list

2018-10-21T07:45:28+00:00

commit 569ccae68b38654f04b6842b034aa33857f605fe upstream.

rules in nftables a free'd using kfree, but protected by rcu, i.e. we
must wait for a grace period to elapse.

Normal removal patch does this, but nf_tables_newrule() doesn't obey
this rule during error handling.

It calls nft_trans_rule_add() *after* linking rule, and, if that
fails to allocate memory, it unlinks the rule and then kfree() it --
this is unsafe.

Switch order -- first add rule to transaction list, THEN link it
to public list.

Note: nft_trans_rule_add() uses GFP_KERNEL; it will not fail so this
is not a problem in practice (spotted only during code review).

Fixes: 0628b123c96d12 ("netfilter: nfnetlink: add batch support and use it from nf_tables")
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
[bwh: Backported to 3.16: Some function names are different]
Signed-off-by: Ben Hutchings

netfilter: IDLETIMER: be syzkaller friendly

2018-06-16T21:22:22+00:00

commit cfc2c740533368b96e2be5e0a4e8c3cace7d9814 upstream.

We had one report from syzkaller [1]

First issue is that INIT_WORK() should be done before mod_timer()
or we risk timer being fired too soon, even with a 1 second timer.

Second issue is that we need to reject too big info->timeout
to avoid overflows in msecs_to_jiffies(info->timeout * 1000), or
risk looping, if result after overflow is 0.

[1]
WARNING: CPU: 1 PID: 5129 at kernel/workqueue.c:1444 __queue_work+0xdf4/0x1230 kernel/workqueue.c:1444
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 5129 Comm: syzkaller159866 Not tainted 4.16.0-rc1+ #230
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:53
 panic+0x1e4/0x41c kernel/panic.c:183
 __warn+0x1dc/0x200 kernel/panic.c:547
 report_bug+0x211/0x2d0 lib/bug.c:184
 fixup_bug.part.11+0x37/0x80 arch/x86/kernel/traps.c:178
 fixup_bug arch/x86/kernel/traps.c:247 [inline]
 do_error_trap+0x2d7/0x3e0 arch/x86/kernel/traps.c:296
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315
 invalid_op+0x22/0x40 arch/x86/entry/entry_64.S:988
RIP: 0010:__queue_work+0xdf4/0x1230 kernel/workqueue.c:1444
RSP: 0018:ffff8801db507538 EFLAGS: 00010006
RAX: ffff8801aeb46080 RBX: ffff8801db530200 RCX: ffffffff81481404
RDX: 0000000000000100 RSI: ffffffff86b42640 RDI: 0000000000000082
RBP: ffff8801db507758 R08: 1ffff1003b6a0de5 R09: 000000000000000c
R10: ffff8801db5073f0 R11: 0000000000000020 R12: 1ffff1003b6a0eb6
R13: ffff8801b1067ae0 R14: 00000000000001f8 R15: dffffc0000000000
 queue_work_on+0x16a/0x1c0 kernel/workqueue.c:1488
 queue_work include/linux/workqueue.h:488 [inline]
 schedule_work include/linux/workqueue.h:546 [inline]
 idletimer_tg_expired+0x44/0x60 net/netfilter/xt_IDLETIMER.c:116
 call_timer_fn+0x228/0x820 kernel/time/timer.c:1326
 expire_timers kernel/time/timer.c:1363 [inline]
 __run_timers+0x7ee/0xb70 kernel/time/timer.c:1666
 run_timer_softirq+0x4c/0x70 kernel/time/timer.c:1692
 __do_softirq+0x2d7/0xb85 kernel/softirq.c:285
 invoke_softirq kernel/softirq.c:365 [inline]
 irq_exit+0x1cc/0x200 kernel/softirq.c:405
 exiting_irq arch/x86/include/asm/apic.h:541 [inline]
 smp_apic_timer_interrupt+0x16b/0x700 arch/x86/kernel/apic/apic.c:1052
 apic_timer_interrupt+0xa9/0xb0 arch/x86/entry/entry_64.S:829
 
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:777 [inline]
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x5e/0xba kernel/locking/spinlock.c:184
RSP: 0018:ffff8801c20173c8 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff12
RAX: dffffc0000000000 RBX: 0000000000000282 RCX: 0000000000000006
RDX: 1ffffffff0d592cd RSI: 1ffff10035d68d23 RDI: 0000000000000282
RBP: ffff8801c20173d8 R08: 1ffff10038402e47 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff8820e5c8
R13: ffff8801b1067ad8 R14: ffff8801aea7c268 R15: ffff8801aea7c278
 __debug_object_init+0x235/0x1040 lib/debugobjects.c:378
 debug_object_init+0x17/0x20 lib/debugobjects.c:391
 __init_work+0x2b/0x60 kernel/workqueue.c:506
 idletimer_tg_create net/netfilter/xt_IDLETIMER.c:152 [inline]
 idletimer_tg_checkentry+0x691/0xb00 net/netfilter/xt_IDLETIMER.c:213
 xt_check_target+0x22c/0x7d0 net/netfilter/x_tables.c:850
 check_target net/ipv6/netfilter/ip6_tables.c:533 [inline]
 find_check_entry.isra.7+0x935/0xcf0 net/ipv6/netfilter/ip6_tables.c:575
 translate_table+0xf52/0x1690 net/ipv6/netfilter/ip6_tables.c:744
 do_replace net/ipv6/netfilter/ip6_tables.c:1160 [inline]
 do_ip6t_set_ctl+0x370/0x5f0 net/ipv6/netfilter/ip6_tables.c:1686
 nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
 nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
 ipv6_setsockopt+0x10b/0x130 net/ipv6/ipv6_sockglue.c:927
 udpv6_setsockopt+0x45/0x80 net/ipv6/udp.c:1422
 sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2976
 SYSC_setsockopt net/socket.c:1850 [inline]
 SyS_setsockopt+0x189/0x360 net/socket.c:1829
 do_syscall_64+0x282/0x940 arch/x86/entry/common.c:287

Fixes: 0902b469bd25 ("netfilter: xtables: idletimer target implementation")
Signed-off-by: Eric Dumazet 
Reported-by: syzkaller 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Ben Hutchings

netfilter: nat: cope with negative port range

2018-06-16T21:22:15+00:00

commit db57ccf0f2f4624b4c4758379f8165277504fbd7 upstream.

syzbot reported a division by 0 bug in the netfilter nat code:

divide error: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
    (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 4168 Comm: syzkaller034710 Not tainted 4.16.0-rc1+ #309
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:nf_nat_l4proto_unique_tuple+0x291/0x530
net/netfilter/nf_nat_proto_common.c:88
RSP: 0018:ffff8801b2466778 EFLAGS: 00010246
RAX: 000000000000f153 RBX: ffff8801b2466dd8 RCX: ffff8801b2466c7c
RDX: 0000000000000000 RSI: ffff8801b2466c58 RDI: ffff8801db5293ac
RBP: ffff8801b24667d8 R08: ffff8801b8ba6dc0 R09: ffffffff88af5900
R10: ffff8801b24666f0 R11: 0000000000000000 R12: 000000002990f153
R13: 0000000000000001 R14: 0000000000000000 R15: ffff8801b2466c7c
FS:  00000000017e3880(0000) GS:ffff8801db500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000208fdfe4 CR3: 00000001b5340002 CR4: 00000000001606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
  dccp_unique_tuple+0x40/0x50 net/netfilter/nf_nat_proto_dccp.c:30
  get_unique_tuple+0xc28/0x1c10 net/netfilter/nf_nat_core.c:362
  nf_nat_setup_info+0x1c2/0xe00 net/netfilter/nf_nat_core.c:406
  nf_nat_redirect_ipv6+0x306/0x730 net/netfilter/nf_nat_redirect.c:124
  redirect_tg6+0x7f/0xb0 net/netfilter/xt_REDIRECT.c:34
  ip6t_do_table+0xc2a/0x1a30 net/ipv6/netfilter/ip6_tables.c:365
  ip6table_nat_do_chain+0x65/0x80 net/ipv6/netfilter/ip6table_nat.c:41
  nf_nat_ipv6_fn+0x594/0xa80 net/ipv6/netfilter/nf_nat_l3proto_ipv6.c:302
  nf_nat_ipv6_local_fn+0x33/0x5d0
net/ipv6/netfilter/nf_nat_l3proto_ipv6.c:407
  ip6table_nat_local_fn+0x2c/0x40 net/ipv6/netfilter/ip6table_nat.c:69
  nf_hook_entry_hookfn include/linux/netfilter.h:120 [inline]
  nf_hook_slow+0xba/0x1a0 net/netfilter/core.c:483
  nf_hook include/linux/netfilter.h:243 [inline]
  NF_HOOK include/linux/netfilter.h:286 [inline]
  ip6_xmit+0x10ec/0x2260 net/ipv6/ip6_output.c:277
  inet6_csk_xmit+0x2fc/0x580 net/ipv6/inet6_connection_sock.c:139
  dccp_transmit_skb+0x9ac/0x10f0 net/dccp/output.c:142
  dccp_connect+0x369/0x670 net/dccp/output.c:564
  dccp_v6_connect+0xe17/0x1bf0 net/dccp/ipv6.c:946
  __inet_stream_connect+0x2d4/0xf00 net/ipv4/af_inet.c:620
  inet_stream_connect+0x58/0xa0 net/ipv4/af_inet.c:684
  SYSC_connect+0x213/0x4a0 net/socket.c:1639
  SyS_connect+0x24/0x30 net/socket.c:1620
  do_syscall_64+0x282/0x940 arch/x86/entry/common.c:287
  entry_SYSCALL_64_after_hwframe+0x26/0x9b
RIP: 0033:0x441c69
RSP: 002b:00007ffe50cc0be8 EFLAGS: 00000217 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 0000000000441c69
RDX: 000000000000001c RSI: 00000000208fdfe4 RDI: 0000000000000003
RBP: 00000000006cc018 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000538 R11: 0000000000000217 R12: 0000000000403590
R13: 0000000000403620 R14: 0000000000000000 R15: 0000000000000000
Code: 48 89 f0 83 e0 07 83 c0 01 38 d0 7c 08 84 d2 0f 85 46 02 00 00 48 8b
45 c8 44 0f b7 20 e8 88 97 04 fd 31 d2 41 0f b7 c4 4c 89 f9 <41> f7 f6 48
c1 e9 03 48 b8 00 00 00 00 00 fc ff df 0f b6 0c 01
RIP: nf_nat_l4proto_unique_tuple+0x291/0x530
net/netfilter/nf_nat_proto_common.c:88 RSP: ffff8801b2466778

The problem is that currently we don't have any check on the
configured port range. A port range == -1 triggers the bug, while
other negative values may require a very long time to complete the
following loop.

This commit addresses the issue swapping the two ends on negative
ranges. The check is performed in nf_nat_l4proto_unique_tuple() since
the nft nat loads the port values from nft registers at runtime.

v1 -> v2: use the correct 'Fixes' tag
v2 -> v3: update commit message, drop unneeded READ_ONCE()

Fixes: 5b1158e909ec ("[NETFILTER]: Add NAT support for nf_conntrack")
Reported-by: syzbot+8012e198bd037f4871e5@syzkaller.appspotmail.com
Signed-off-by: Paolo Abeni 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Ben Hutchings

netfilter: x_tables: fix missing timer initialization in xt_LED

2018-06-16T21:22:14+00:00

commit 10414014bc085aac9f787a5890b33b5605fbcfc4 upstream.

syzbot reported that xt_LED may try to use the ledinternal->timer
without previously initializing it:

------------[ cut here ]------------
kernel BUG at kernel/time/timer.c:958!
invalid opcode: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
    (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 1826 Comm: kworker/1:2 Not tainted 4.15.0+ #306
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Workqueue: ipv6_addrconf addrconf_dad_work
RIP: 0010:__mod_timer kernel/time/timer.c:958 [inline]
RIP: 0010:mod_timer+0x7d6/0x13c0 kernel/time/timer.c:1102
RSP: 0018:ffff8801d24fe9f8 EFLAGS: 00010293
RAX: ffff8801d25246c0 RBX: ffff8801aec6cb50 RCX: ffffffff816052c6
RDX: 0000000000000000 RSI: 00000000fffbd14b RDI: ffff8801aec6cb68
RBP: ffff8801d24fec98 R08: 0000000000000000 R09: 1ffff1003a49fd6c
R10: ffff8801d24feb28 R11: 0000000000000005 R12: dffffc0000000000
R13: ffff8801d24fec70 R14: 00000000fffbd14b R15: ffff8801af608f90
FS:  0000000000000000(0000) GS:ffff8801db500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000206d6fd0 CR3: 0000000006a22001 CR4: 00000000001606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
  led_tg+0x1db/0x2e0 net/netfilter/xt_LED.c:75
  ip6t_do_table+0xc2a/0x1a30 net/ipv6/netfilter/ip6_tables.c:365
  ip6table_raw_hook+0x65/0x80 net/ipv6/netfilter/ip6table_raw.c:42
  nf_hook_entry_hookfn include/linux/netfilter.h:120 [inline]
  nf_hook_slow+0xba/0x1a0 net/netfilter/core.c:483
  nf_hook.constprop.27+0x3f6/0x830 include/linux/netfilter.h:243
  NF_HOOK include/linux/netfilter.h:286 [inline]
  ndisc_send_skb+0xa51/0x1370 net/ipv6/ndisc.c:491
  ndisc_send_ns+0x38a/0x870 net/ipv6/ndisc.c:633
  addrconf_dad_work+0xb9e/0x1320 net/ipv6/addrconf.c:4008
  process_one_work+0xbbf/0x1af0 kernel/workqueue.c:2113
  worker_thread+0x223/0x1990 kernel/workqueue.c:2247
  kthread+0x33c/0x400 kernel/kthread.c:238
  ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:429
Code: 85 2a 0b 00 00 4d 8b 3c 24 4d 85 ff 75 9f 4c 8b bd 60 fd ff ff e8 bb
57 10 00 65 ff 0d 94 9a a1 7e e9 d9 fc ff ff e8 aa 57 10 00 <0f> 0b e8 a3
57 10 00 e9 14 fb ff ff e8 99 57 10 00 4c 89 bd 70
RIP: __mod_timer kernel/time/timer.c:958 [inline] RSP: ffff8801d24fe9f8
RIP: mod_timer+0x7d6/0x13c0 kernel/time/timer.c:1102 RSP: ffff8801d24fe9f8
---[ end trace f661ab06f5dd8b3d ]---

The ledinternal struct can be shared between several different
xt_LED targets, but the related timer is currently initialized only
if the first target requires it. Fix it by unconditionally
initializing the timer struct.

v1 -> v2: call del_timer_sync() unconditionally, too.

Fixes: 268cb38e1802 ("netfilter: x_tables: add LED trigger target")
Reported-by: syzbot+10c98dc5725c6c8fc7fb@syzkaller.appspotmail.com
Signed-off-by: Paolo Abeni 
Signed-off-by: Pablo Neira Ayuso 
[bwh: Backported to 3.16: Keep using setup_timer()]
Signed-off-by: Ben Hutchings

netfilter: xt_RATEEST: acquire xt_rateest_mutex for hash insert

2018-06-16T21:22:07+00:00

commit 7dc68e98757a8eccf8ca7a53a29b896f1eef1f76 upstream.

rateest_hash is supposed to be protected by xt_rateest_mutex,
and, as suggested by Eric, lookup and insert should be atomic,
so we should acquire the xt_rateest_mutex once for both.

So introduce a non-locking helper for internal use and keep the
locking one for external.

Reported-by: 
Fixes: 5859034d7eb8 ("[NETFILTER]: x_tables: add RATEEST target")
Signed-off-by: Cong Wang 
Reviewed-by: Florian Westphal 
Reviewed-by: Eric Dumazet 
Signed-off-by: Pablo Neira Ayuso 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

netfilter: xt_bpf: add overflow checks

2018-03-03T15:51:43+00:00

commit 6ab405114b0b229151ef06f4e31c7834dd09d0c0 upstream.

Check whether inputs from userspace are too long (explicit length field too
big or string not null-terminated) to avoid out-of-bounds reads.

As far as I can tell, this can at worst lead to very limited kernel heap
memory disclosure or oopses.

This bug can be triggered by an unprivileged user even if the xt_bpf module
is not loaded: iptables is available in network namespaces, and the xt_bpf
module can be autoloaded.

Triggering the bug with a classic BPF filter with fake length 0x1000 causes
the following KASAN report:

==================================================================
BUG: KASAN: slab-out-of-bounds in bpf_prog_create+0x84/0xf0
Read of size 32768 at addr ffff8801eff2c494 by task test/4627

CPU: 0 PID: 4627 Comm: test Not tainted 4.15.0-rc1+ #1
[...]
Call Trace:
 dump_stack+0x5c/0x85
 print_address_description+0x6a/0x260
 kasan_report+0x254/0x370
 ? bpf_prog_create+0x84/0xf0
 memcpy+0x1f/0x50
 bpf_prog_create+0x84/0xf0
 bpf_mt_check+0x90/0xd6 [xt_bpf]
[...]
Allocated by task 4627:
 kasan_kmalloc+0xa0/0xd0
 __kmalloc_node+0x47/0x60
 xt_alloc_table_info+0x41/0x70 [x_tables]
[...]
The buggy address belongs to the object at ffff8801eff2c3c0
                which belongs to the cache kmalloc-2048 of size 2048
The buggy address is located 212 bytes inside of
                2048-byte region [ffff8801eff2c3c0, ffff8801eff2cbc0)
[...]
==================================================================

Fixes: e6f30c731718 ("netfilter: x_tables: add xt_bpf match")
Signed-off-by: Jann Horn 
Signed-off-by: Pablo Neira Ayuso 
[bwh: Backported to 3.16:
 - Add len variable in bpf_mt_check()
 - Drop change in __bpf_mt_check_path()]
Signed-off-by: Ben Hutchings