Hi folks, I tried to limit the number of ssh connections per peer and for the entire network, but on the second run of ipora.sh (attached) I got this hiccup: [342160.909708] general protection fault: 0000 [#2] SMP PTI [342160.909719] CPU: 6 PID: 4049 Comm: iptables Tainted: P D OE 4.19.0-0.bpo.1-amd64 #1 Debian 4.19.12-1~bpo9+1 [342160.909722] Hardware name: /DH87MC, BIOS MCH8710H.86A.0157.2014.0530.1830 05/30/2014 [342160.909732] RIP: 0010:rb_erase+0xae/0x360 [342160.909737] Code: 4d 89 50 08 4d 85 c9 74 5b 48 83 c8 01 48 89 0a 49 89 01 c3 48 8b 0f 48 89 ca 48 83 e2 fc 48 85 d2 48 89 d0 0f 84 44 02 00 00 <48> 3b 7a 10 0f 84 42 02 00 00 4c 89 42 08 4d 85 c0 0f 84 1e 02 00 [342160.909741] RSP: 0018:ffffaab98c277d18 EFLAGS: 00010206 [342160.909745] RAX: 38c7f9ef71cb4db8 RBX: ffff8cdab34be1b8 RCX: 38c7f9ef71cb4dba [342160.909749] RDX: 38c7f9ef71cb4db8 RSI: ffff8cd3e8eed5d0 RDI: ffff8cdaaa8bd3c0 [342160.909752] RBP: ffff8cdaaa8bd3e0 R08: 0000000000000000 R09: ffffffffc1e97300 [342160.909755] R10: ffff8cdaaa8bd3c0 R11: 0000000000000001 R12: ffff8cdaaa8bd3c0 [342160.909758] R13: ffff8cd3e8eed5d0 R14: ffff8cd3e8eed808 R15: ffff8cd3e8eed000 [342160.909762] FS: 00007ffaf7fe7700(0000) GS:ffff8cdabeb80000(0000) knlGS:0000000000000000 [342160.909766] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [342160.909769] CR2: 0000562950d25738 CR3: 000000024c20a001 CR4: 00000000001606e0 [342160.909772] Call Trace: [342160.909785] nf_conncount_destroy+0x59/0xc0 [nf_conncount] [342160.909795] cleanup_match+0x45/0x70 [ip_tables] [342160.909804] ? next_arg+0x42/0x110 [342160.909808] cleanup_entry+0x3e/0xc0 [ip_tables] [342160.909814] __do_replace+0x1a1/0x250 [ip_tables] [342160.909821] do_ipt_set_ctl+0x161/0x1c0 [ip_tables] [342160.909829] nf_setsockopt+0x44/0x70 [342160.909838] __sys_setsockopt+0x82/0xe0 [342160.909844] __x64_sys_setsockopt+0x20/0x30 [342160.909851] do_syscall_64+0x55/0x110 [342160.909858] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [342160.909862] RIP: 0033:0x7ffaf721bc7a [342160.909866] Code: 89 d0 48 83 c4 08 48 3d 01 f0 ff ff 73 01 c3 48 8b 0d 12 f2 2a 00 f7 d8 64 89 01 48 83 c8 ff c3 49 89 ca b8 36 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d ee f1 2a 00 f7 d8 64 89 01 48 [342160.909869] RSP: 002b:00007ffc3a7512c8 EFLAGS: 00000202 ORIG_RAX: 0000000000000036 [342160.909874] RAX: ffffffffffffffda RBX: 0000562950d24010 RCX: 00007ffaf721bc7a [342160.909877] RDX: 0000000000000040 RSI: 0000000000000000 RDI: 0000000000000004 [342160.909880] RBP: 0000562950d25050 R08: 0000000000000740 R09: 0000562950d252c0 [342160.909883] R10: 0000562950d24ff0 R11: 0000000000000202 R12: 0000562950d24018 [342160.909885] R13: 0000562950d24018 R14: 0000562950d24ff0 R15: 0000000000000004 [342160.909889] Modules linked in: xt_connlimit(E) nf_conncount(E) ip6t_rpfilter(E) ipt_REJECT(E) nf_reject_ipv4(E) ip6t_REJECT(E) nf_reject_ipv6(E) xt_conntrack(E) ip_set(E) nfnetlink(E) ebtable_nat(E) ebtable_broute(E) ip6table_nat(E) nf_nat_ipv6(E) ip6table_mangle(E) ip6table_security(E) ip6table_raw(E) iptable_security(E) iptable_raw(E) veth(E) uas(E) usb_storage(E) ebtable_filter(E) ebtables(E) ip6table_filter(E) ip6_tables(E) pci_stub(E) vboxpci(OE) vboxnetadp(OE) vboxnetflt(OE) vboxdrv(OE) cpufreq_powersave(E) cpufreq_userspace(E) cpufreq_conservative(E) xt_CHECKSUM(E) iptable_mangle(E) ipt_MASQUERADE(E) iptable_nat(E) nf_nat_ipv4(E) nf_nat(E) nf_conntrack(E) nf_defrag_ipv6(E) nf_defrag_ipv4(E) xt_tcpudp(E) xfrm_user(E) xfrm4_tunnel(E) tunnel4(E) ipcomp(E) xfrm_ipcomp(E) esp4(E) ah4(E) af_key(E) [342160.909949] xfrm_algo(E) rpcsec_gss_krb5(E) iptable_filter(E) nfsv4(E) dns_resolver(E) nfs(E) lockd(E) grace(E) fscache(E) overlay(E) bridge(E) stp(E) llc(E) fuse(E) binfmt_misc(E) iTCO_wdt(E) iTCO_vendor_support(E) intel_rapl(E) x86_pkg_temp_thermal(E) intel_powerclamp(E) snd_hda_codec_hdmi(E) coretemp(E) kvm_intel(E) snd_hda_codec_realtek(E) snd_hda_codec_generic(E) snd_hda_intel(E) snd_hda_codec(E) kvm(E) irqbypass(E) snd_hda_core(E) snd_hwdep(E) snd_pcm(E) crct10dif_pclmul(E) crc32_pclmul(E) ghash_clmulni_intel(E) intel_cstate(E) snd_timer(E) mei_me(E) snd(E) intel_uncore(E) joydev(E) evdev(E) sg(E) lpc_ich(E) mei(E) soundcore(E) intel_rapl_perf(E) pcspkr(E) button(E) video(E) pcc_cpufreq(E) nvidia_drm(POE) drm_kms_helper(E) drm(E) nvidia_modeset(POE) nvidia(POE) auth_rpcgss(E) sunrpc(E) ipmi_devintf(E) [342160.910015] ipmi_msghandler(E) ip_tables(E) x_tables(E) autofs4(E) ext4(E) crc16(E) mbcache(E) jbd2(E) fscrypto(E) ecb(E) btrfs(E) zstd_decompress(E) zstd_compress(E) xxhash(E) raid10(E) raid456(E) async_raid6_recov(E) async_memcpy(E) async_pq(E) async_xor(E) async_tx(E) xor(E) raid6_pq(E) libcrc32c(E) crc32c_generic(E) raid0(E) multipath(E) linear(E) raid1(E) dm_mod(E) md_mod(E) sr_mod(E) sd_mod(E) cdrom(E) hid_generic(E) usbhid(E) hid(E) ahci(E) crc32c_intel(E) ehci_pci(E) libahci(E) sata_sil24(E) aesni_intel(E) xhci_pci(E) aes_x86_64(E) crypto_simd(E) xhci_hcd(E) libata(E) ehci_hcd(E) cryptd(E) glue_helper(E) i2c_i801(E) scsi_mod(E) e1000e(E) usbcore(E) usb_common(E) fan(E) thermal(E) [342160.910081] ---[ end trace fc760b1020579f4a ]--- [342160.910086] RIP: 0010:rb_erase+0xae/0x360 [342160.910090] Code: 4d 89 50 08 4d 85 c9 74 5b 48 83 c8 01 48 89 0a 49 89 01 c3 48 8b 0f 48 89 ca 48 83 e2 fc 48 85 d2 48 89 d0 0f 84 44 02 00 00 <48> 3b 7a 10 0f 84 42 02 00 00 4c 89 42 08 4d 85 c0 0f 84 1e 02 00 [342160.910093] RSP: 0018:ffffaab98ada7d18 EFLAGS: 00010282 [342160.910097] RAX: c7387535db4090f8 RBX: ffff8cdab34be2c0 RCX: c7387535db4090fa [342160.910100] RDX: c7387535db4090f8 RSI: ffff8cd3ca2be130 RDI: ffff8cdaaa8bd1e0 [342160.910103] RBP: ffff8cdaaa8bd200 R08: 0000000000000000 R09: ffffffffc1e97301 [342160.910106] R10: ffff8cdaaa8bd1e0 R11: 0000000000000001 R12: ffff8cdaaa8bd1e0 [342160.910109] R13: ffff8cd3ca2be130 R14: ffff8cd3ca2be808 R15: ffff8cd3ca2be000 [342160.910113] FS: 00007ffaf7fe7700(0000) GS:ffff8cdabeb80000(0000) knlGS:0000000000000000 [342160.910116] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [342160.910119] CR2: 0000562950d25738 CR3: 000000024c20a001 CR4: 00000000001606e0 After the first run of ipora I used 3 remote hosts to setup 2 ssh connections each in parallel back to my host. The limit of 5 did *not* work. ??? This is Debian's backports kernel for 4.19.12. Does this sound familiar? If not, then I would be glad to help tracking down this problem. The hiccup is not 100% reproducible, though. Regards Harri
Attachment:
ipora.sh
Description: application/shellscript
