linux-stable.git/net/netfilter, branch linux-3.2.y

netfilter: IDLETIMER: be syzkaller friendly

2018-05-31T23:30:17+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: x_tables: fix missing timer initialization in xt_LED

2018-05-31T23:30:15+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 3.2: Keep using setup_timer()]
Signed-off-by: Ben Hutchings

netfilter: xt_RATEEST: acquire xt_rateest_mutex for hash insert

2018-05-31T23:30:13+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 3.2: adjust context]
Signed-off-by: Ben Hutchings

netfilter: xt_TCPMSS: add more sanity tests on tcph->doff

2018-02-13T18:32:22+00:00

commit 2638fd0f92d4397884fd991d8f4925cb3f081901 upstream.

Denys provided an awesome KASAN report pointing to an use
after free in xt_TCPMSS

I have provided three patches to fix this issue, either in xt_TCPMSS or
in xt_tcpudp.c. It seems xt_TCPMSS patch has the smallest possible
impact.

Signed-off-by: Eric Dumazet 
Reported-by: Denys Fedoryshchenko 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Ben Hutchings

netfilter: xt_TCPMSS: correct return value in tcpmss_mangle_packet

2018-02-13T18:32:21+00:00

commit 1205e1fa615805c9efa97303b552cf445965752a upstream.

In commit b396966c4 (netfilter: xt_TCPMSS: Fix missing fragmentation handling),
I attempted to add safe fragment handling to xt_TCPMSS.  However, Andy Padavan
of Project N56U correctly points out that returning XT_CONTINUE in this
function does not work.  The callers (tcpmss_tg[46]) expect to receive a value
of 0 in order to return XT_CONTINUE.

Signed-off-by: Phil Oester 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Ben Hutchings

netfilter: xt_TCPMSS: fix handling of malformed TCP header and options

2018-02-13T18:32:21+00:00

commit 71ffe9c77dd7a2b62207953091efa8dafec958dd upstream.

Make sure the packet has enough room for the TCP header and
that it is not malformed.

While at it, store tcph->doff*4 in a variable, as it is used
several times.

This patch also fixes a possible off by one in case of malformed
TCP options.

Reported-by: Julian Anastasov 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Ben Hutchings

netfilter: xt_TCPMSS: Fix missing fragmentation handling

2018-02-13T18:32:21+00:00

commit b396966c4688522863572927cb30aa874b3ec504 upstream.

Similar to commit bc6bcb59 ("netfilter: xt_TCPOPTSTRIP: fix
possible mangling beyond packet boundary"), add safe fragment
handling to xt_TCPMSS.

Signed-off-by: Phil Oester 
Signed-off-by: Pablo Neira Ayuso 
[bwh: Backported to 3.2: Change parameters for tcpmss_mangle_packet() as
 done upstream in commit 70d19f805f8c "netfilter: xt_TCPMSS: Fix IPv6 default
 MSS too"]
Signed-off-by: Ben Hutchings

netfilter: xt_TCPOPTSTRIP: don't use tcp_hdr()

2018-02-13T18:32:21+00:00

commit ed82c437320c48a4032492f4a55a7e2c934158b6 upstream.

In (bc6bcb5 netfilter: xt_TCPOPTSTRIP: fix possible mangling beyond
packet boundary), the use of tcp_hdr was introduced. However, we
cannot assume that skb->transport_header is set for non-local packets.

Cc: Florian Westphal 
Reported-by: Phil Oester 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Ben Hutchings

netfilter: xt_TCPOPTSTRIP: fix possible mangling beyond packet boundary

2018-02-13T18:32:20+00:00

commit bc6bcb59dd7c184d229f9e86d08aa56059938a4c upstream.

This target assumes that tcph->doff is well-formed, that may be well
not the case. Add extra sanity checkings to avoid possible crash due
to read/write out of the real packet boundary. After this patch, the
default action on malformed TCP packets is to drop them. Moreover,
fragments are skipped.

Reported-by: Rafal Kupka 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Ben Hutchings

netfilter: xt_socket: fix compilation warnings with gcc 4.7

2017-11-11T13:34:44+00:00

commit 6703aa74ad1ba2e598bb49a37f7518da1195bacb upstream.

This patch fixes compilation warnings in xt_socket with gcc-4.7.

In file included from net/netfilter/xt_socket.c:22:0:
net/netfilter/xt_socket.c: In function ‘socket_mt6_v1’:
include/net/netfilter/nf_tproxy_core.h:175:23: warning: ‘sport’ may be used uninitialized in this function [-Wmaybe-uninitialized]
net/netfilter/xt_socket.c:265:16: note: ‘sport’ was declared here
In file included from net/netfilter/xt_socket.c:22:0:
include/net/netfilter/nf_tproxy_core.h:175:23: warning: ‘dport’ may be used uninitialized in this function [-Wmaybe-uninitialized]
net/netfilter/xt_socket.c:265:9: note: ‘dport’ was declared here
In file included from net/netfilter/xt_socket.c:22:0:
include/net/netfilter/nf_tproxy_core.h:175:6: warning: ‘saddr’ may be used uninitialized in this function [-Wmaybe-uninitialized]
net/netfilter/xt_socket.c:264:27: note: ‘saddr’ was declared here
In file included from net/netfilter/xt_socket.c:22:0:
include/net/netfilter/nf_tproxy_core.h:175:6: warning: ‘daddr’ may be used uninitialized in this function [-Wmaybe-uninitialized]
net/netfilter/xt_socket.c:264:19: note: ‘daddr’ was declared here
In file included from net/netfilter/xt_socket.c:22:0:
net/netfilter/xt_socket.c: In function ‘socket_match.isra.4’:
include/net/netfilter/nf_tproxy_core.h:75:2: warning: ‘protocol’ may be used uninitialized in this function [-Wmaybe-uninitialized]
net/netfilter/xt_socket.c:113:5: note: ‘protocol’ was declared here
In file included from include/net/tcp.h:37:0,
                 from net/netfilter/xt_socket.c:17:
include/net/inet_hashtables.h:356:45: warning: ‘sport’ may be used uninitialized in this function [-Wmaybe-uninitialized]
net/netfilter/xt_socket.c:112:16: note: ‘sport’ was declared here
In file included from net/netfilter/xt_socket.c:22:0:
include/net/netfilter/nf_tproxy_core.h:106:23: warning: ‘dport’ may be used uninitialized in this function [-Wmaybe-uninitialized]
net/netfilter/xt_socket.c:112:9: note: ‘dport’ was declared here
In file included from include/net/tcp.h:37:0,
                 from net/netfilter/xt_socket.c:17:
include/net/inet_hashtables.h:356:15: warning: ‘saddr’ may be used uninitialized in this function [-Wmaybe-uninitialized]
net/netfilter/xt_socket.c:111:16: note: ‘saddr’ was declared here
In file included from include/net/tcp.h:37:0,
                 from net/netfilter/xt_socket.c:17:
include/net/inet_hashtables.h:356:15: warning: ‘daddr’ may be used uninitialized in this function [-Wmaybe-uninitialized]
net/netfilter/xt_socket.c:111:9: note: ‘daddr’ was declared here
In file included from net/netfilter/xt_socket.c:22:0:
net/netfilter/xt_socket.c: In function ‘socket_mt6_v1’:
include/net/netfilter/nf_tproxy_core.h:175:23: warning: ‘sport’ may be used uninitialized in this function [-Wmaybe-uninitialized]
net/netfilter/xt_socket.c:268:16: note: ‘sport’ was declared here
In file included from net/netfilter/xt_socket.c:22:0:
include/net/netfilter/nf_tproxy_core.h:175:23: warning: ‘dport’ may be used uninitialized in this function [-Wmaybe-uninitialized]
net/netfilter/xt_socket.c:268:9: note: ‘dport’ was declared here
In file included from net/netfilter/xt_socket.c:22:0:
include/net/netfilter/nf_tproxy_core.h:175:6: warning: ‘saddr’ may be used uninitialized in this function [-Wmaybe-uninitialized]
net/netfilter/xt_socket.c:267:27: note: ‘saddr’ was declared here
In file included from net/netfilter/xt_socket.c:22:0:
include/net/netfilter/nf_tproxy_core.h:175:6: warning: ‘daddr’ may be used uninitialized in this function [-Wmaybe-uninitialized]
net/netfilter/xt_socket.c:267:19: note: ‘daddr’ was declared here

Signed-off-by: Pablo Neira Ayuso 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings