On two desktop systems running Debian Buster with Linux kernel version 5.0.7, I was experiencing a problem when Shorewall6 was stopping or restarting. This kernel backtrace appeared in the logs:
[ 28.932323] WARNING: CPU: 1 PID: 169 at net/netfilter/nft_compat.c:82 nft_xt_put.part.9+0x21/0x30 [nft_compat]
[ 28.932325] Modules linked in: ip6t_REJECT(E) nf_reject_ipv6(E) nft_chain_nat_ipv6(E) nf_nat_ipv6(E) nft_chain_route_ipv6(E) xt_multiport(E) nf_log_ipv6(E) xt_recent(E) xt_comment(E) xt_hashlimit(E) xt_addrtype(E) xt_mark(E) xt_CT(E) nfnetlink_log(E) xt_NFLOG(E) nf_log_ipv4(E) nf_log_common(E) xt_LOG(E) nf_nat_tftp(E) nf_nat_snmp_basic(E) nf_conntrack_snmp(E) nf_nat_sip(E) nf_nat_pptp(E) nf_nat_irc(E) nf_nat_h323(E) nf_nat_ftp(E) nf_nat_amanda(E) ts_kmp(E) nf_conntrack_amanda(E) nf_conntrack_sane(E) nf_conntrack_tftp(E) nf_conntrack_sip(E) nf_conntrack_pptp(E) nf_conntrack_proto_gre(E) nf_conntrack_netlink(E) nf_conntrack_netbios_ns(E) nf_conntrack_broadcast(E) nf_conntrack_irc(E) nf_conntrack_h323(E) nf_conntrack_ftp(E) nft_chain_route_ipv4(E) xt_CHECKSUM(E) nft_chain_nat_ipv4(E) ipt_M
ASQUERADE(E) nf_nat_ipv4(E) nf_nat(E) xt_conntrack(E) nf_conntrack(E) nf_defrag_ipv6(E) nf_defrag_ipv4(E) ipt_REJECT(E) nf_reject_ipv4(E) nft_counter(E) xt_tcpudp(E) nft_compat(E) tun(E) bridge(E) stp(E)
[ 28.932357] llc(E) devlink(E) nf_tables(E) nfnetlink(E) msr(E) cmac(E) cpufreq_userspace(E) cpufreq_powersave(E) cpufreq_conservative(E) bnep(E) binfmt_misc(E) nls_ascii(E) nls_cp437(E) vfat(E) fat(E) ext4(E) mbcache(E) jbd2(E) fscrypto(E) intel_rapl(E) x86_pkg_temp_thermal(E) intel_powerclamp(E) kvm_intel(E) kvm(E) irqbypass(E) crct10dif_pclmul(E) crc32_pclmul(E) efi_pstore(E) ghash_clmulni_intel(E) btusb(E) mei_wdt(E) btrtl(E) btbcm(E) btintel(E) bluetooth(E) arc4(E) aesni_intel(E) snd_hda_codec_hdmi(E) drbg(E) iwldvm(E) aes_x86_64(E) ansi_cprng(E) crypto_simd(E) ecdh_generic(E) cryptd(E) glue_helper(E) crc16(E) snd_hda_codec_idt(E) mac80211(E) hp_wmi(E) snd_hda_codec_generic(E) sparse_keymap(E) joydev(E) ledtrig_audio(E) snd_hda_intel(E) iwlwifi(E) snd_hda_codec(E) intel_cstate(E) w
mi_bmof(E) uvcvideo(E) intel_uncore(E) sg(E) serio_raw(E) intel_rapl_perf(E) snd_hda_core(E) videobuf2_vmalloc(E) tpm_infineon(E) videobuf2_memops(E) videobuf2_v4l2(E) videobuf2_common(E) snd_hwdep(E)
[ 28.932408] videodev(E) media(E) snd_pcm(E) efivars(E) snd_timer(E) iTCO_wdt(E) cfg80211(E) iTCO_vendor_support(E) rfkill(E) snd(E) tpm_tis(E) tpm_tis_core(E) soundcore(E) tpm(E) mei_me(E) mei(E) rng_core(E) evdev(E) hp_accel(E) lis3lv02d(E) input_polldev(E) pcc_cpufreq(E) hp_wireless(E) battery(E) ac(E) coretemp(E) loop(E) parport_pc(E) ppdev(E) lp(E) parport(E) bfq(E) efivarfs(E) ip_tables(E) x_tables(E) autofs4(E) btrfs(E) xor(E) zstd_decompress(E) zstd_compress(E) raid6_pq(E) libcrc32c(E) crc32c_generic(E) dm_mod(E) sr_mod(E) cdrom(E) sd_mod(E) hid_generic(E) usbhid(E) hid(E) sdhci_pci(E) cqhci(E) i915(E) ahci(E) i2c_algo_bit(E) libahci(E) sdhci(E) drm_kms_helper(E) crc32c_intel(E) mmc_core(E) xhci_pci(E) libata(E) ehci_pci(E) xhci_hcd(E) ehci_hcd(E) scsi_mod(E) psmouse(E) lpc_ich(
E) firewire_ohci(E) firewire_core(E) crc_itu_t(E) e1000e(E) drm(E) usbcore(E) thermal(E) wmi(E) video(E) button(E)
[ 28.932469] CPU: 1 PID: 169 Comm: kworker/1:2 Tainted: G E 5.0.7 #1
[ 28.932471] Hardware name: Hewlett-Packard HP EliteBook 8470p/179B, BIOS 68ICF Ver. F.31 09/24/2012
[ 28.932481] Workqueue: events nf_tables_trans_destroy_work [nf_tables]
[ 28.932486] RIP: 0010:nft_xt_put.part.9+0x21/0x30 [nft_compat]
[ 28.932489] Code: ff ff ff f3 c3 0f 1f 40 00 0f 1f 44 00 00 48 8b 07 48 39 c7 75 14 48 83 ef 80 be 80 00 00 00 e8 f5 54 14 f6 b8 01 00 00 00 c3 <0f> 0b eb e8 90 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 53
[ 28.932491] RSP: 0018:ffffb119411a3db8 EFLAGS: 00010206
[ 28.932493] RAX: ffff9a33fe12b300 RBX: ffff9a33fe12b600 RCX: 0000000000000000
[ 28.932495] RDX: 0000000000000000 RSI: ffff9a33fe12b678 RDI: ffff9a33fe12b600
[ 28.932497] RBP: ffffffffc10e3400 R08: ffffffffc10e3180 R09: ffffffffc1288800
[ 28.932498] R10: 0000000000000001 R11: 0000000000000001 R12: ffff9a34081d9e40
[ 28.932500] R13: dead000000000200 R14: dead000000000100 R15: ffffffffc12a5088
[ 28.932503] FS: 0000000000000000(0000) GS:ffff9a3436840000(0000) knlGS:0000000000000000
[ 28.932505] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 28.932506] CR2: 0000557e2fdb5000 CR3: 00000001f6e5e002 CR4: 00000000001606e0
[ 28.932508] Call Trace:
[ 28.932516] __nft_match_destroy.isra.10+0x69/0xa0 [nft_compat]
[ 28.932526] nf_tables_expr_destroy+0x1a/0x40 [nf_tables]
[ 28.932533] nf_tables_rule_destroy+0x4f/0x80 [nf_tables]
[ 28.932541] nf_tables_trans_destroy_work+0x1dd/0x200 [nf_tables]
[ 28.932548] process_one_work+0x191/0x380
[ 28.932553] worker_thread+0x204/0x3b0
[ 28.932557] ? rescuer_thread+0x340/0x340
[ 28.932560] kthread+0xf8/0x130
[ 28.932563] ? kthread_create_worker_on_cpu+0x70/0x70
[ 28.932569] ret_from_fork+0x35/0x40
[ 28.932573] ---[ end trace fc35add4fa3b2bde ]---
[ 29.015565] general protection fault: 0000 [#1] SMP PTI
[ 29.015574] CPU: 3 PID: 2069 Comm: ip6tables-resto Tainted: G W E 5.0.7 #1
[ 29.015577] Hardware name: Hewlett-Packard HP EliteBook 8470p/179B, BIOS 68ICF Ver. F.31 09/24/2012
[ 29.015586] RIP: 0010:strcmp+0x4/0x20
[ 29.015590] Code: 74 1a 49 39 d0 48 89 d0 75 e9 48 85 d2 74 05 c6 44 17 ff 00 48 c7 c0 f9 ff ff ff c3 f3 c3 f3 c3 66 0f 1f 44 00 00 48 83 c7 01 <0f> b6 47 ff 48 83 c6 01 3a 46 ff 75 07 84 c0 75 eb 31 c0 c3 19 c0
[ 29.015593] RSP: 0018:ffffb119428e78e0 EFLAGS: 00010282
[ 29.015597] RAX: 00000000ffffffff RBX: ffffb11941401264 RCX: 000000000000000b
[ 29.015600] RDX: ffff9a33fe12b600 RSI: ffffb11941401264 RDI: 894810247c8d4849
[ 29.015602] RBP: ffff9a340486c510 R08: 0000000000000003 R09: ffff9a33f6d58128
[ 29.015605] R10: ffffb119428e7930 R11: 0000000000000002 R12: 0000000000000000
[ 29.015607] R13: ffffffffc1294e70 R14: ffff9a340486c500 R15: 894810247c8d4838
[ 29.015611] FS: 00007f26d10ba740(0000) GS:ffff9a34368c0000(0000) knlGS:0000000000000000
[ 29.015614] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 29.015617] CR2: 00007f26d118a6d0 CR3: 00000001fd760003 CR4: 00000000001606e0
[ 29.015619] Call Trace:
[ 29.015631] nft_match_select_ops+0x92/0x210 [nft_compat]
[ 29.015646] nf_tables_expr_parse+0x13e/0x1e0 [nf_tables]
[ 29.015653] ? kvmalloc_node+0x43/0x70
[ 29.015663] nf_tables_newrule+0x247/0x8b0 [nf_tables]
[ 29.015671] nfnetlink_rcv_batch+0x499/0x720 [nfnetlink]
[ 29.015679] ? skb_queue_tail+0x1b/0x50
[ 29.015685] ? _cond_resched+0x16/0x40
[ 29.015691] ? kmem_cache_alloc_node_trace+0x1c1/0x1f0
[ 29.015695] ? __insert_vmap_area+0x99/0x100
[ 29.015702] ? refcount_inc_checked+0x5/0x30
[ 29.015707] ? apparmor_capable+0x70/0xb0
[ 29.015713] ? __nla_parse+0x34/0x150
[ 29.015719] nfnetlink_rcv+0x113/0x136 [nfnetlink]
[ 29.015725] netlink_unicast+0x1b9/0x240
[ 29.015731] netlink_sendmsg+0x2d0/0x3c0
[ 29.015735] sock_sendmsg+0x36/0x40
[ 29.015739] ___sys_sendmsg+0x2e9/0x300
[ 29.015744] ? page_add_file_rmap+0x13/0x1f0
[ 29.015750] ? filemap_map_pages+0x183/0x380
[ 29.015756] ? __handle_mm_fault+0xb89/0x1200
[ 29.015760] ? refcount_inc_checked+0x5/0x30
[ 29.015764] ? apparmor_capable+0x70/0xb0
[ 29.015768] ? security_capable+0x35/0x50
[ 29.015772] ? release_sock+0x19/0x90
[ 29.015776] ? __sys_sendmsg+0x63/0xa0
[ 29.015780] __sys_sendmsg+0x63/0xa0
[ 29.015787] do_syscall_64+0x55/0xf0
[ 29.015792] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 29.015797] RIP: 0033:0x7f26d11bcc74
[ 29.015800] Code: 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b5 0f 1f 80 00 00 00 00 48 8d 05 89 5a 0c 00 8b 00 85 c0 75 13 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 41 54 41 89 d4 55 48 89 f5 53
[ 29.015803] RSP: 002b:00007ffd02e15868 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[ 29.015807] RAX: ffffffffffffffda RBX: 00007ffd02e15880 RCX: 00007f26d11bcc74
[ 29.015809] RDX: 0000000000000000 RSI: 00007ffd02e16900 RDI: 0000000000000003
[ 29.015812] RBP: 00007ffd02e16f80 R08: 0000000000000004 R09: 0000000000000000
[ 29.015814] R10: 00007ffd02e168ec R11: 0000000000000246 R12: 0000564c33d862a0
[ 29.015816] R13: 00007ffd02e19850 R14: 00007ffd02e15870 R15: 00007ffd02e19888
[ 29.015820] Modules linked in: ip6t_REJECT(E) nf_reject_ipv6(E) nft_chain_nat_ipv6(E) nf_nat_ipv6(E) nft_chain_route_ipv6(E) xt_multiport(E) nf_log_ipv6(E) xt_recent(E) xt_comment(E) xt_hashlimit(E) xt_addrtype(E) xt_mark(E) xt_CT(E) nfnetlink_log(E) xt_NFLOG(E) nf_log_ipv4(E) nf_log_common(E) xt_LOG(E) nf_nat_tftp(E) nf_nat_snmp_basic(E) nf_conntrack_snmp(E) nf_nat_sip(E) nf_nat_pptp(E) nf_nat_irc(E) nf_nat_h323(E) nf_nat_ftp(E) nf_nat_amanda(E) ts_kmp(E) nf_conntrack_amanda(E) nf_conntrack_sane(E) nf_conntrack_tftp(E) nf_conntrack_sip(E) nf_conntrack_pptp(E) nf_conntrack_proto_gre(E) nf_conntrack_netlink(E) nf_conntrack_netbios_ns(E) nf_conntrack_broadcast(E) nf_conntrack_irc(E) nf_conntrack_h323(E) nf_conntrack_ftp(E) nft_chain_route_ipv4(E) xt_CHECKSUM(E) nft_chain_nat_ipv4(E) ipt_M
ASQUERADE(E) nf_nat_ipv4(E) nf_nat(E) xt_conntrack(E) nf_conntrack(E) nf_defrag_ipv6(E) nf_defrag_ipv4(E) ipt_REJECT(E) nf_reject_ipv4(E) nft_counter(E) xt_tcpudp(E) nft_compat(E) tun(E) bridge(E) stp(E)
[ 29.015861] llc(E) devlink(E) nf_tables(E) nfnetlink(E) msr(E) cmac(E) cpufreq_userspace(E) cpufreq_powersave(E) cpufreq_conservative(E) bnep(E) binfmt_misc(E) nls_ascii(E) nls_cp437(E) vfat(E) fat(E) ext4(E) mbcache(E) jbd2(E) fscrypto(E) intel_rapl(E) x86_pkg_temp_thermal(E) intel_powerclamp(E) kvm_intel(E) kvm(E) irqbypass(E) crct10dif_pclmul(E) crc32_pclmul(E) efi_pstore(E) ghash_clmulni_intel(E) btusb(E) mei_wdt(E) btrtl(E) btbcm(E) btintel(E) bluetooth(E) arc4(E) aesni_intel(E) snd_hda_codec_hdmi(E) drbg(E) iwldvm(E) aes_x86_64(E) ansi_cprng(E) crypto_simd(E) ecdh_generic(E) cryptd(E) glue_helper(E) crc16(E) snd_hda_codec_idt(E) mac80211(E) hp_wmi(E) snd_hda_codec_generic(E) sparse_keymap(E) joydev(E) ledtrig_audio(E) snd_hda_intel(E) iwlwifi(E) snd_hda_codec(E) intel_cstate(E) w
mi_bmof(E) uvcvideo(E) intel_uncore(E) sg(E) serio_raw(E) intel_rapl_perf(E) snd_hda_core(E) videobuf2_vmalloc(E) tpm_infineon(E) videobuf2_memops(E) videobuf2_v4l2(E) videobuf2_common(E) snd_hwdep(E)
[ 29.015913] videodev(E) media(E) snd_pcm(E) efivars(E) snd_timer(E) iTCO_wdt(E) cfg80211(E) iTCO_vendor_support(E) rfkill(E) snd(E) tpm_tis(E) tpm_tis_core(E) soundcore(E) tpm(E) mei_me(E) mei(E) rng_core(E) evdev(E) hp_accel(E) lis3lv02d(E) input_polldev(E) pcc_cpufreq(E) hp_wireless(E) battery(E) ac(E) coretemp(E) loop(E) parport_pc(E) ppdev(E) lp(E) parport(E) bfq(E) efivarfs(E) ip_tables(E) x_tables(E) autofs4(E) btrfs(E) xor(E) zstd_decompress(E) zstd_compress(E) raid6_pq(E) libcrc32c(E) crc32c_generic(E) dm_mod(E) sr_mod(E) cdrom(E) sd_mod(E) hid_generic(E) usbhid(E) hid(E) sdhci_pci(E) cqhci(E) i915(E) ahci(E) i2c_algo_bit(E) libahci(E) sdhci(E) drm_kms_helper(E) crc32c_intel(E) mmc_core(E) xhci_pci(E) libata(E) ehci_pci(E) xhci_hcd(E) ehci_hcd(E) scsi_mod(E) psmouse(E) lpc_ich(
E) firewire_ohci(E) firewire_core(E) crc_itu_t(E) e1000e(E) drm(E) usbcore(E) thermal(E) wmi(E) video(E) button(E)
[ 29.015977] ---[ end trace fc35add4fa3b2bdf ]---
[ 29.613482] RIP: 0010:strcmp+0x4/0x20
[ 29.613486] Code: 74 1a 49 39 d0 48 89 d0 75 e9 48 85 d2 74 05 c6 44 17 ff 00 48 c7 c0 f9 ff ff ff c3 f3 c3 f3 c3 66 0f 1f 44 00 00 48 83 c7 01 <0f> b6 47 ff 48 83 c6 01 3a 46 ff 75 07 84 c0 75 eb 31 c0 c3 19 c0
[ 29.613488] RSP: 0018:ffffb119428e78e0 EFLAGS: 00010282
[ 29.613490] RAX: 00000000ffffffff RBX: ffffb11941401264 RCX: 000000000000000b
[ 29.613492] RDX: ffff9a33fe12b600 RSI: ffffb11941401264 RDI: 894810247c8d4849
[ 29.613493] RBP: ffff9a340486c510 R08: 0000000000000003 R09: ffff9a33f6d58128
[ 29.613494] R10: ffffb119428e7930 R11: 0000000000000002 R12: 0000000000000000
[ 29.613495] R13: ffffffffc1294e70 R14: ffff9a340486c500 R15: 894810247c8d4838
[ 29.613497] FS: 00007f26d10ba740(0000) GS:ffff9a34368c0000(0000) knlGS:0000000000000000
[ 29.613499] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 29.613500] CR2: 00007f26d118a6d0 CR3: 00000001fd760003 CR4: 00000000001606e0On one of the two systems, this would result in the system failing to shut down properly: the kernel would hang completely when trying to shut down.
The problem is known, and can be fixed by this patch, which has been queued in the stable 5.0 tree. It will hopefully be included in the 5.0.8 version.