[Bug 1247] New: Module crash due to broken count

[bugzilla-daemon at netfilter.org]

https://bugzilla.netfilter.org/show_bug.cgi?id=1247

            Bug ID: 1247
           Summary: Module crash due to broken count
           Product: netfilter/iptables
           Version: unspecified
          Hardware: other
                OS: other
            Status: NEW
          Severity: blocker
          Priority: P5
         Component: unknown
          Assignee: netfilter-buglog at lists.netfilter.org
          Reporter: netfilternetfilter at gmail.com

The configuration I use is a NixOS keepalived setup on AWS (which uses Xen)
configured with per packet round robin routing in a direct routing setup, which
in turn uses ipvs.

Symptoms are ksoftirqd using 100% of the CPU resulting in what looks like a DoS
attack on the machine. 

The module repeatedly crashes when in this mode with a message similar to the
one below.

[root at keepalive:~]# uname -a
Linux keepalive 4.15.17 #1-NixOS SMP Thu Apr 12 10:31:21 UTC 2018 x86_64
GNU/Linux

It is the same problem as described on
https://github.com/NixOS/nixpkgs/issues/39078. 

[  782.525457] ------------[ cut here ]------------                             
[  782.525467] refcount_t hit zero at ip_vs_conn_put+0x31/0x40 [ip_vs] in
sh[15519], uid/euid: 497/497                                                    
[  782.525477] WARNING: CPU: 0 PID: 15519 at ../kernel/panic.c:657
refcount_error_report+0x94/0x9e
[  782.525477] Modules linked in: ip_vs_rr cirrus ttm sb_edac edac_core
drm_kms_helper crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc mousedev
drm aesni_intel aes_x86_64 crypto_simd glue_helper cryptd psmouse evdev
input_leds led_class intel_agp fb_sys_fops syscopyarea sysfillrect
intel_rapl_perf mac_hid intel_gtt serio_raw sysimgblt agpgart i2c_piix4
i2c_core ata_generic pata_acpi floppy cfg80211 rfkill button loop macvlan ip_vs
nf_conntrack libcrc32c crc32c_generic ip_tables x_tables ipv6 crc_ccitt autofs4
ext4 crc16 mbcache jbd2 fscrypto ata_piix libata atkbd libps2 scsi_mod
crc32c_intel i8042 rtc_cmos serio af_packet dm_mod dax fuse xen_netfront
xen_blkfront
[  782.525532] CPU: 0 PID: 15519 Comm: sh Tainted: G        W        4.15.17
#1-NixOS
[  782.525533] Hardware name: Xen HVM domU, BIOS 4.2.amazon 08/24/2006
[  782.525535] RIP: 0010:refcount_error_report+0x94/0x9e
[  782.525536] RSP: 0000:ffffa344dde039c8 EFLAGS: 00010296
[  782.525537] RAX: 0000000000000057 RBX: ffffffff92f20e06 RCX:
0000000000000006
[  782.525541] RDX: 0000000000000007 RSI: 0000000000000086 RDI:
ffffa344dde165c0
[  782.525541] RBP: ffffa344dde03b08 R08: 0000000000000218 R09:
0000000000000004
[  782.525542] R10: ffffffff93006a80 R11: 0000000000000001 R12:
ffffa344d68cd100
[  782.525543] R13: 00000000000001f1 R14: ffffffff92f12fb0 R15:
0000000000000004
[  782.525544] FS:  00007fc9d2040fc0(0000) GS:ffffa344dde00000(0000)
knlGS:0000000000000000
[  782.525545] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  782.525546] CR2: 000000000262a000 CR3: 0000000016a0c004 CR4:
00000000001606f0
[  782.525548] Call Trace:
[  782.525551]  <IRQ>
[  782.525557]  ex_handler_refcount+0x4e/0x80
[  782.525558]  fixup_exception+0x33/0x40
[  782.525563]  do_trap+0x83/0x140
[  782.525565]  do_error_trap+0x83/0xf0
[  782.525568]  ? ip_vs_conn_drop_conntrack+0x120/0x1a5 [ip_vs]
[  782.525574]  ? ip_finish_output2+0x29c/0x390
[  782.525575]  ? ip_finish_output2+0x1a2/0x390
[  782.525580]  invalid_op+0x1b/0x40
[  782.525582] RIP: 0010:ip_vs_conn_put+0x31/0x40 [ip_vs]
[  782.525583] RSP: 0000:ffffa344dde03bb8 EFLAGS: 00010246
[  782.525584] RAX: 0000000000000001 RBX: ffffa344df31cf00 RCX:
ffffa344d7450198
[  782.525585] RDX: 0000000000000003 RSI: 00000000fffffe01 RDI:
ffffa344d7450140
[  782.525586] RBP: 0000000000000002 R08: 0000000000000476 R09:
0000000000000000
[  782.525587] R10: ffffa344dde03b28 R11: ffffa344df200000 R12:
ffffa344d7d09000
[  782.525587] R13: ffffa344def3a980 R14: ffffffffc04f6e20 R15:
0000000000000008
[  782.525591]  ip_vs_in.part.29.constprop.36+0x34f/0x640 [ip_vs]
[  782.525593]  ? ip_vs_conn_out_get+0xe0/0xe0 [ip_vs]
[  782.525596]  ip_vs_remote_request4+0x47/0xa0 [ip_vs]
[  782.525598]  ? ip_vs_in.part.29.constprop.36+0x640/0x640 [ip_vs]
[  782.525600]  nf_hook_slow+0x43/0xc0
[  782.525602]  ip_local_deliver+0xac/0xc0
[  782.525604]  ? ip_rcv_finish+0x400/0x400
[  782.525606]  ip_rcv+0x26c/0x380
[  782.525610]  __netif_receive_skb_core+0x3a0/0xb10
[  782.525629]  ? inet_gro_receive+0x23c/0x2b0
[  782.525631]  ? netif_receive_skb_internal+0x24/0xb0
[  782.525633]  netif_receive_skb_internal+0x24/0xb0
[  782.525635]  napi_gro_receive+0xb8/0xe0
[  782.525638]  xennet_poll+0x676/0xb40 [xen_netfront]
[  782.525641]  net_rx_action+0x139/0x3a0
[  782.525644]  __do_softirq+0xde/0x2b4
[  782.525646]  irq_exit+0xae/0xb0
[  782.525651]  xen_evtchn_do_upcall+0x2c/0x40
[  782.525653]  xen_hvm_callback_vector+0x7d/0x90
[  782.525654]  </IRQ>
[  782.525656] RIP: 0033:0x7fc9d11c91f9
[  782.525656] RSP: 002b:00007ffebe8a2ea0 EFLAGS: 00000202 ORIG_RAX:
ffffffffffffff0c
[  782.525658] RAX: 00000000ffffffff RBX: 0000000002609808 RCX:
0000000000000054
[  782.525658] RDX: 0000000000000001 RSI: 0000000002605440 RDI:
00000000025f940e
[  782.525659] RBP: 00000000025f940e R08: 000000000260213d R09:
1999999999999999
[  782.525660] R10: 000000000262a808 R11: 00000000025f942d R12:
00000000025f940e
[  782.525661] R13: 00007fc9d1301e20 R14: 00000000025f9408 R15:
00007fc9d1302720
[  782.525662] Code: 48 8b 95 80 00 00 00 41 55 49 8d 8c 24 e0 05 00 00 45 8b
84 24 38 04 00 00 41 89 c1 48 89 de 48 c7 c7 a8 2f f2 92 e8 7c fa ff ff <0f> 0b
58 5b 5d 41 5c 41 5d c3 0f 1f 44 00 00 55 48 89 e5 41 56 
[  782.525684] ---[ end trace 429a7a27ee858cfb ]---

-- 
You are receiving this mail because:
You are watching all bug changes.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.netfilter.org/pipermail/netfilter-buglog/attachments/20180423/0209d4c7/attachment.html>