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Date: Fri, 05 Dec 2014 03:23:54 +0100
From: Smart Weblications GmbH - Florian Wiessner
<f.wiessner@...rt-weblications.de>
To: Julian Anastasov <ja@....bg>,
Steffen Klassert <steffen.klassert@...unet.com>
CC: netdev@...r.kernel.org, LKML <linux-kernel@...r.kernel.org>,
stable@...r.kernel.org
Subject: Re: 3.12.33 - BUG xfrm_selector_match+0x25/0x2f6
Hi,
Am 05.12.2014 00:15, schrieb Julian Anastasov:
>
> Hello,
>
> On Thu, 4 Dec 2014, Steffen Klassert wrote:
>
>>> [16623.096721] Call Trace:
>>> [16623.096744] <IRQ>
>>> [16623.096749] [<ffffffff81547a7c>] ? xfrm_sk_policy_lookup+0x44/0x9b
>>> [16623.096802] [<ffffffff81547ef7>] ? xfrm_lookup+0x91/0x446
>>> [16623.096832] [<ffffffff81541316>] ? ip_route_me_harder+0x150/0x1b0
>>> [16623.096865] [<ffffffffa01b6457>] ? ip_vs_route_me_harder+0x86/0x91 [ip_vs]
>>> [16623.096899] [<ffffffffa01b797a>] ? ip_vs_out+0x2d3/0x5bc [ip_vs]
>>> [16623.096930] [<ffffffff81501420>] ? ip_rcv_finish+0x2b8/0x2b8
>>
>> I really wonder why the xfrm_sk_policy_lookup codepath is taken here.
>> It looks like this is the processing of an inbound ipv4 packet that
>> is going to be rerouted to the output path by ipvs, so this packet
>> should not have socket context at all.
>
> In above trace looks like IPVS-NAT is used between
> local client and some real server. IPVS handles this skb
> at LOCAL_IN and calls ip_vs_route_me_harder(). If we have
> skb->sk at LOCAL_IN, my first thought is about early demux.
>
> If I remember correctly, looking at commit f5a41847acc535e2
> ("ipvs: move ip_route_me_harder for ICMP") that introduced
> this rerouting (2.6.37), it was needed because at that time TCP
> used rt_src from received skb to select daddr in ip_send_reply().
> As packets to server are DNAT-ed and packets to client are
> SNAT-ed we used rerouting to fill rt_src with correct IP
> after SNAT.
>
> Now when routing cache is removed in 3.6 and
> tcp_v4_send_reset() is changed to provide ip_hdr(skb)->saddr
> instead of rt_src it should be safe to remove this rerouting,
> it is enough that ip_hdr(skb)->saddr was updated on IPVS-SNAT at
> LOCAL_IN. In fact, rt_src was removed early in 3.0 with
> commit 0a5ebb8000c5362 ("ipv4: Pass explicit daddr arg to
> ip_send_reply().").
>
> This is only to explain above stack. Not sure
> if problem is related somehow to early demux but such
> commits look interesting:
>
> - commit 6b8dbcf2c44fd7a ("bridge: netfilter: orphan skb before invoking
> ip netfilter hooks")
>
> Also, it would be good to know which 3.x kernel between
> 3.13 and 3.17 fixes the problem, it will narrow the search.
>
i tried with 3.12.33 without any XFRM and now got this one (which is reproducable):
[ 233.956012] BUG: unable to handle kernel NULL pointer dereference at 00000000
00000014
[ 233.956218] IP: [<ffffffffa013a470>] nf_ct_seqadj_set+0x60/0x90 [nf_conntrack
]
[ 233.956371] PGD 0
[ 233.956493] Oops: 0000 [#1] SMP
[ 233.956680] Modules linked in: netconsole xt_nat xt_multiport veth iptable_ma
ngle xt_mark nf_conntrack_netlink nfnetlink
ip_vs_rr ipt_MASQUERADE iptable_nat
nf_nat_ipv4 nf_conntrack_ipv4 nf_defrag_ipv4 ipt_REJECT xt_tcpudp iptable_filter
ip_tables cpufreq_ondemand cpufreq_powersave
cpufreq_conservative cpufreq_users pace
ocfs2_stack_o2cb ocfs2_dlm bridge stp llc bonding fuse nf_conntrack_ftp 802
1q openvswitch gre vxlan xt_conntrack x_tables
ocfs2_dlmfs dlm sctp ocfs2 ocfs2_ nodemanager
ocfs2_stackglue configfs rbd kvm_intel kvm coretemp ip_vs_ftp ip_vs
nf_nat nf_conntrack psmouse i2c_i801 serio_raw lpc_ich
mfd_core evdev btrfs lzo_ decompress lzo_compress
[ 233.960221] CPU: 2 PID: 29996 Comm: vsftpd Not tainted 3.12.33 #4
[ 233.960298] Hardware name: Supermicro X9SCI/X9SCA/X9SCI/X9SCA, BIOS 1.1a 09/2
8/2011
[ 233.960395] task: ffff88075e87a2c0 ti: ffff8806a7444000 task.ti: ffff8806a744
4000
[ 233.960486] RIP: 0010:[<ffffffffa013a470>] [<ffffffffa013a470>] nf_ct_seqadj
_set+0x60/0x90 [nf_conntrack]
[ 233.960632] RSP: 0018:ffff88083fc83998 EFLAGS: 00010206
[ 233.960709] RAX: 000000000000000c RBX: ffff8806cab452cc RCX: 0000000000000003
[ 233.960791] RDX: 0000000000000029 RSI: 0000000000000003 RDI: ffff8806cab452cc
[ 233.960875] RBP: 00000000ee38035a R08: ffff8807e2b1edc0 R09: ffff88083fc839a8
[ 233.960957] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000003
[ 233.961041] R13: 0000000000000000 R14: 0000000000000003 R15: ffff8806a75a50bc
[ 233.961124] FS: 00007ff22daec700(0000) GS:ffff88083fc80000(0000) knlGS:00000
00000000000
[ 233.961226] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 233.961303] CR2: 0000000000000014 CR3: 00000006b3259000 CR4: 00000000000407e0
[ 233.961384] Stack:
[ 233.961460] ffff880815612b60 0000000000000012 0000000000000014 ffff8806cab45
2c8
[ 233.961776] ffff8806a75a5001 ffffffffa014f681 0000000000000000 ffffffff00000
045
[ 233.962095] ffff880800000048 0000001b00000003 ffff88083fc83a70 ffff880815612
b60
[ 233.962411] Call Trace:
[ 233.962482] <IRQ>
[ 233.962538] [<ffffffffa014f681>] ? __nf_nat_mangle_tcp_packet+0x109/0x120 [n
f_nat]
[ 233.962762] [<ffffffffa017749e>] ? ip_vs_ftp_out.part.8+0x2b2/0x338 [ip_vs_f
tp]
[ 233.962866] [<ffffffff814cb8c0>] ? __domain_mapping+0x25d/0x2a3
[ 233.962949] [<ffffffff8154140c>] ? fib_table_lookup+0xe4/0x255
[ 233.963032] [<ffffffffa015f858>] ? ip_vs_app_pkt_out+0x105/0x18b [ip_vs]
[ 233.963110] [<ffffffffa0162ffc>] ? tcp_snat_handler+0x6b/0x320 [ip_vs]
[ 233.963189] [<ffffffffa0155d3d>] ? ip_vs_conn_out_get_proto+0x1c/0x25 [ip_vs
]
[ 233.963284] [<ffffffffa0158937>] ? ip_vs_out+0x290/0x5bc [ip_vs]
[ 233.963362] [<ffffffff8150f544>] ? ip_frag_mem+0x2a/0x2a
[ 233.963442] [<ffffffff81508e1f>] ? nf_iterate+0x42/0x80
[ 233.963519] [<ffffffff81508ec6>] ? nf_hook_slow+0x69/0xff
[ 233.963595] [<ffffffff8150f544>] ? ip_frag_mem+0x2a/0x2a
[ 233.963667] [<ffffffff8150f8ae>] ? ip_forward+0x22d/0x2cf
[ 233.963744] [<ffffffff814e57ce>] ? __netif_receive_skb_core+0x5f0/0x66c
[ 233.963826] [<ffffffff814e59df>] ? process_backlog+0x13e/0x13e
[ 233.963911] [<ffffffffa0455e09>] ? br_handle_frame_finish+0x382/0x382 [bridg
e]
[ 233.964008] [<ffffffff814e5a2b>] ? netif_receive_skb+0x4c/0x7d
[ 233.964090] [<ffffffffa0455d95>] ? br_handle_frame_finish+0x30e/0x382 [bridg
e]
[ 233.964186] [<ffffffffa0455fda>] ? br_handle_frame+0x1d1/0x217 [bridge]
[ 233.964267] [<ffffffff814e567d>] ? __netif_receive_skb_core+0x49f/0x66c
[ 233.964350] [<ffffffff814e592b>] ? process_backlog+0x8a/0x13e
[ 233.964429] [<ffffffff814e5c31>] ? net_rx_action+0xa2/0x1c0
[ 233.964508] [<ffffffff81047e2e>] ? __do_softirq+0xf6/0x24f
[ 233.964588] [<ffffffff8106cbfd>] ? account_system_time+0x10f/0x169
[ 233.964669] [<ffffffff815ad7dc>] ? call_softirq+0x1c/0x30
[ 233.964743] <EOI>
[ 233.964801] [<ffffffff8100464d>] ? do_softirq+0x2c/0x5f
[ 233.965013] [<ffffffff81047ca1>] ? local_bh_enable+0x67/0x85
[ 233.965088] [<ffffffff81511689>] ? ip_finish_output+0x2c9/0x322
[ 233.965165] [<ffffffff8151240a>] ? ip_queue_xmit+0x2b7/0x2f0
[ 233.965239] [<ffffffff81524772>] ? tcp_transmit_skb+0x6ef/0x755
[ 233.965316] [<ffffffff815250e8>] ? tcp_write_xmit+0x886/0x9cb
[ 233.965391] [<ffffffff8152527a>] ? __tcp_push_pending_frames+0x24/0x7e
[ 233.965473] [<ffffffff8151a33c>] ? tcp_sendmsg+0xa4c/0xbfc
[ 233.965550] [<ffffffff814d3477>] ? sock_aio_write+0xe3/0xfd
[ 233.965631] [<ffffffff81122f4d>] ? do_sync_write+0x59/0x79
[ 233.965709] [<ffffffff811239e3>] ? vfs_write+0xc4/0x182
[ 233.965786] [<ffffffff81123daf>] ? SyS_write+0x45/0x7c
[ 233.965864] [<ffffffff815ac35b>] ? tracesys+0xdd/0xe2
[ 233.965940] Code: 68 14 4d 01 c5 45 85 e4 74 46 f0 80 4f 78 40 48 8d 5f 04 48
89 df e8 00 12 47 e1 31 c0 41 83 fe 02 0f 97
c0 48 6b c0 0c 4c 01 e8 <8b> 70 08 39 70 04
74 08 89 ea 0f ca 39 10 79 0d 89 70 04 44 01
[ 233.969602] RIP [<ffffffffa013a470>] nf_ct_seqadj_set+0x60/0x90 [nf_conntrac
k]
[ 233.969746] RSP <ffff88083fc83998>
[ 233.969816] CR2: 0000000000000014
[ 233.969919] ---[ end trace c6faf7aa989b11c2 ]---
[ 233.969999] Kernel panic - not syncing: Fatal exception in interrupt
[ 233.970081] Rebooting in 10 seconds..
[ 244.029931] ACPI MEMORY or I/O RESET_REG.
node01:/ocfs2/usr/src/linux-3.12.33/scripts# ./decodecode < /tmp/oops-ipvsftp.txt
[ 233.965940] Code: 68 14 4d 01 c5 45 85 e4 74 46 f0 80 4f 78 40 48 8d 5f 04 48
89 df e8 00 12 47 e1 31 c0 41 83 fe 02 0f 97 c0 48 6b c0 0c 4c 01 e8 <8b> 70 08
39 70 04 74 08 89 ea 0f ca 39 10 79 0d 89 70 04 44 01
All code
========
0: 68 14 4d 01 c5 pushq $0xffffffffc5014d14
5: 45 85 e4 test %r12d,%r12d
8: 74 46 je 0x50
a: f0 80 4f 78 40 lock orb $0x40,0x78(%rdi)
f: 48 8d 5f 04 lea 0x4(%rdi),%rbx
13: 48 89 df mov %rbx,%rdi
16: e8 00 12 47 e1 callq 0xffffffffe147121b
1b: 31 c0 xor %eax,%eax
1d: 41 83 fe 02 cmp $0x2,%r14d
21: 0f 97 c0 seta %al
24: 48 6b c0 0c imul $0xc,%rax,%rax
28: 4c 01 e8 add %r13,%rax
2b:* 8b 70 08 mov 0x8(%rax),%esi <-- trapping
instruction
2e: 39 70 04 cmp %esi,0x4(%rax)
31: 74 08 je 0x3b
33: 89 ea mov %ebp,%edx
35: 0f ca bswap %edx
37: 39 10 cmp %edx,(%rax)
39: 79 0d jns 0x48
3b: 89 70 04 mov %esi,0x4(%rax)
3e: 44 rex.R
3f: 01 .byte 0x1
Code starting with the faulting instruction
===========================================
0: 8b 70 08 mov 0x8(%rax),%esi
3: 39 70 04 cmp %esi,0x4(%rax)
6: 74 08 je 0x10
8: 89 ea mov %ebp,%edx
a: 0f ca bswap %edx
c: 39 10 cmp %edx,(%rax)
e: 79 0d jns 0x1d
10: 89 70 04 mov %esi,0x4(%rax)
13: 44 rex.R
14: 01 .byte 0x1
setup is like this:
#virtual=<myVIP>:21
# real=10.10.1.20:21 masq
# real=10.10.1.21:21 masq
# real=10.10.1.22:21 masq
# real=10.10.1.23:21 masq
# persistent=600
# service=ftp
# scheduler=rr
# protocol=tcp
# checktype=connect
( i remarked it to prevent fruther crashes...)
when ip_vs_ftp is loaded and someone trying to make a ftp connection, the system
panics instantly.
10.10.1.20 - 10.10.1.23 are lxc-containers using veth connected to the bridge
running on 4 different nodes. The node running ldirector/ipvsadm has also one of
those containers running (don't know if that matters)
brctl show
bridge name bridge id STP enabled interfaces
br0 8000.00259052bbf4 no bond0
vethMKELUc
vethXdWGqf
vethgJMmEb
vethmKNqFc
I disabled the ftp server lxc container on the node doing ip_vs, so that the
endpoint of the connection is not on the same node and tried again but with the
same result.
Unfortunatelly i cannot test with newer kernels than 3.12, because ocfs2 is
somehow broken in >= 3.14
--
Mit freundlichen Grüßen,
Florian Wiessner
Smart Weblications GmbH
Martinsberger Str. 1
D-95119 Naila
fon.: +49 9282 9638 200
fax.: +49 9282 9638 205
24/7: +49 900 144 000 00 - 0,99 EUR/Min*
http://www.smart-weblications.de
--
Sitz der Gesellschaft: Naila
Geschäftsführer: Florian Wiessner
HRB-Nr.: HRB 3840 Amtsgericht Hof
*aus dem dt. Festnetz, ggf. abweichende Preise aus dem Mobilfunknetz
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