Hello, On Mon, 23 Apr 2018, Net Filter wrote: > I was requested by Pablo Neira Ayuso to report the netfilter bugzilla > ticket https://bugzilla.netfilter.org/show_bug.cgi?id=1247 here. > > The ticket is replicated below for your convenience. > > Start of ticket content: > > 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@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] Looks like the One-packet scheduling mode (-o, --ops) runs with refcnt=0 which upsets the refcount_dec() checks. The solution would be to replace the __ip_vs_conn_put() call in __ip_vs_conn_put_notimer() with refcount_dec_if_one() in ip_vs_conn_unlink(). This will make the refcount subsystem happy. Will test a patch in the following days... > 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 ]--- > -- Regards -- Julian Anastasov <ja@xxxxxx> -- To unsubscribe from this list: send the line "unsubscribe lvs-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
