1.This bug has happened on the following kernel version:
4.4.0-104-generic
4.15.0-13-generic
5.4.0-42-generic
5.4.0-47-generic
2.we cannot reliably reproduce this issue.
3.this patch seems to fix this issue.
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/net/netfilter/x_tables.c?id=175e476b8cdf2a4de7432583b49c871345e4f8a1
4.the following crash dmesg from 5.4.0-47-generic:
[2021-03-19 12:17:53][3581678.514072] audit: audit_lost=1 audit_rate_limit=1 audit_backlog_limit=1024
[2021-03-23 21:57:06][3962019.737898] general protection fault: 0000 [#1] SMP PTI
[2021-03-23 21:57:06][3962019.739019] CPU: 4 PID: 0 Comm: swapper/4 Kdump: loaded Not tainted 5.4.0-47-generic #51~18.04.1-Ubuntu
[2021-03-23 21:57:06][3962019.740433] Hardware name: Tencent Cloud CVM, BIOS seabios-1.9.1-qemu-project.org 04/01/2014
[2021-03-23 21:57:06][3962019.741829] RIP: 0010:ipt_do_table+0x621/0x640 [ip_tables]
[2021-03-23 21:57:06][3962019.742587] Code: ff ff ff 45 31 d2 48 89 85 50 ff ff ff e9 7e fe ff ff 83 ad 70 ff ff ff 01 48 8b bd 78 ff ff ff 8b 85 70 ff ff ff 4c 8b 34 c7 <41> 0f b7 46 5a 49 01 c6 e9 [2021-03-23 21:57:06]18 fb ff ff c7 45 a4 00 00 00 00 e9 e9
[2021-03-23 21:57:06][3962019.745295] RSP: 0018:ffffbcd080184c18 EFLAGS: 00010246
[2021-03-23 21:57:06][3962019.745988] RAX: 0000000000000000 RBX: ffff96b7e9b717b0 RCX: ffffdcd07f70a150
[2021-03-23 21:57:06][3962019.747025] RDX: 000000000001ab6a RSI: ffff96b7e1d98d80 RDI: ffff96b7e1d98d80
[2021-03-23 21:57:06][3962019.748015] RBP: ffffbcd080184d08 R08: 0000000000000008 R09: ffff96b82aca2980
[2021-03-23 21:57:06][3962019.748988] R10: 0000000000000d38 R11: ffff96b7cacaa380 R12: ffff96b833fea000
[2021-03-23 21:57:06][3962019.749927] R13: ffff96b7ebb4a04e R14: 3f13d7139e6d8ccb R15: ffff96b7d2c28f00
[2021-03-23 21:57:06][3962019.750873] FS: 0000000000000000(0000) GS:ffff96b83fb00000(0000) knlGS:0000000000000000
[2021-03-23 21:57:06][3962019.751919] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[2021-03-23 21:57:06][3962019.752720] CR2: 00007fee206258f0 CR3: 0000000f9c428001 CR4: 00000000003606e0
[2021-03-23 21:57:06][3962019.753603] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[2021-03-23 21:57:06][3962019.754619] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[2021-03-23 21:57:06][3962019.755606] Call Trace:
[2021-03-23 21:57:06][3962019.755984] <IRQ>
[2021-03-23 21:57:06][3962019.756282] iptable_filter_hook+0x1f/0x30 [iptable_filter]
[2021-03-23 21:57:06][3962019.757199] nf_hook_slow+0x48/0xc0
[2021-03-23 21:57:06][3962019.757753] ip_forward+0x410/0x480
[2021-03-23 21:57:06][3962019.758350] ? ip4_key_hashfn+0xc0/0xc0
[2021-03-23 21:57:06][3962019.758907] ip_rcv_finish+0x84/0xa0
[2021-03-23 21:57:06][3962019.759469] ip_rcv+0xbc/0xd0
[2021-03-23 21:57:06][3962019.760543] ? ip_rcv_finish_core.isra.18+0x3b0/0x3b0
[2021-03-23 21:57:06][3962019.761916] __netif_receive_skb_one_core+0x86/0xa0
[2021-03-23 21:57:06][3962019.763210] __netif_receive_skb+0x18/0x60
[2021-03-23 21:57:06][3962019.764341] process_backlog+0xa0/0x170
[2021-03-23 21:57:06][3962019.765600] net_rx_action+0x140/0x3c0
[2021-03-23 21:57:06][3962019.766550] __do_softirq+0xe4/0x2da
[2021-03-23 21:57:06][3962019.767792] irq_exit+0xae/0xb0
[2021-03-23 21:57:06][3962019.768857] smp_call_function_single_interrupt+0x48/0xd0
[2021-03-23 21:57:06][3962019.770140] call_function_single_interrupt+0xf/0x20
[2021-03-23 21:57:06][3962019.771315] </IRQ>
[2021-03-23 21:57:06][3962019.772038] RIP: 0010:native_safe_halt+0x12/0x20
This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:
apport-collect 1925124
and then change the status of the bug to 'Confirmed'.
If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.
This change has been made by an automated script, maintained by the Ubuntu Kernel Team.