Comment 32 for bug 1981658

Is anybody knows the steps to reproduce this issue? We are also facing the same below TB in our testbed and we are planning to take the patch mentioned in comment #15.

Even though we are using this kernel from long time and seen this issue on very few nodes.

Appreciate your help in this regard.

Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.026015] TCP: request_sock_TCP: Possible SYN flooding on port 8033. Sending cookies. Check SNMP counters.
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.027529] BUG: kernel NULL pointer dereference, address: 0000000000000008
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.035339] #PF: supervisor read access in kernel mode
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.041083] #PF: error_code(0x0000) - not-present page
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.046838] PGD 0 P4D 0
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.049670] Oops: 0000 [#1] SMP NOPTI
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.053764] CPU: 36 PID: 230 Comm: ksoftirqd/36 Not tainted 5.4.0-122-generic #138~18.04.1
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.063007] Hardware name: Cisco Systems Inc DN2-HW-APL-L/UCSC-C220-M5SX, BIOS C220M5.4.1.3i.0.0713210713 07/13/2021
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.074770] RIP: 0010:tcp_create_openreq_child+0x2e1/0x3e0
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.080907] Code: 08 00 00 41 8b 84 24 18 01 00 00 48 c7 83 80 08 00 00 00 00 00 00 4c 89 e6 4c 89 ef 89 83 c4 05 00 00 49 8b 84 24 f8 00 00 00 <48> 8b 40 08 e8 96 b8 41 00 48 85 c0 0f b7 83 68 05 00 00 74 0a 83
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.101919] RSP: 0018:ffff97b88d207a28 EFLAGS: 00010246
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.107764] RAX: 0000000000000000 RBX: ffff8abb9d1bc600 RCX: 0000000000000007
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.115745] RDX: 0000000000000020 RSI: ffff8abb3c6e1560 RDI: ffff8acdef1b9180
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.123722] RBP: ffff97b88d207a48 R08: 0000000000000000 R09: ffff8aacffc07800
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.131699] R10: 0000000000000514 R11: ffff97b88d207b0f R12: ffff8abb3c6e1560
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.139678] R13: ffff8acdef1b9180 R14: ffff8abdfc1a7500 R15: ffff8adc75529ec0
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.147655] FS: 0000000000000000(0000) GS:ffff8adcff000000(0000) knlGS:0000000000000000
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.156705] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.163144] CR2: 0000000000000008 CR3: 000000594ea0a005 CR4: 00000000007606e0
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.171120] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.179099] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.187076] PKRU: 55555554
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.190101] Call Trace:
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.192841] tcp_v4_syn_recv_sock+0x5a/0x3d0
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.197616] tcp_get_cookie_sock+0x48/0x140
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.202284] cookie_v4_check+0x561/0x660
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.206672] tcp_v4_do_rcv+0x1a0/0x1d0
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.210864] tcp_v4_rcv+0xa86/0xad0
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.214766] ip_protocol_deliver_rcu+0x31/0x1b0
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.219831] ip_local_deliver_finish+0x48/0x50
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.224807] ip_local_deliver+0x7e/0xe0
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.229095] ? ip_protocol_deliver_rcu+0x1b0/0x1b0
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.234456] ip_rcv_finish+0x84/0xa0
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.238453] ip_rcv+0xbc/0xd0
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.241773] __netif_receive_skb_one_core+0x86/0xa0
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.247226] __netif_receive_skb+0x18/0x60
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.251806] process_backlog+0xa9/0x170
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.256093] net_rx_action+0x140/0x3e0
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.260287] ? __switch_to_asm+0x34/0x70
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.264664] __do_softirq+0xe4/0x2da
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.268666] run_ksoftirqd+0x2b/0x40
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.272662] smpboot_thread_fn+0xfc/0x170
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.277146] kthread+0x121/0x140
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.280755] ? sort_range+0x30/0x30
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.284655] ? kthread_park+0x90/0x90
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.289259] ret_from_fork+0x1f/0x40
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.293714] Modules linked in: binfmt_misc ipt_rpfilter xt_CT iptable_raw ip_set_hash_ip ip_set_hash_net ipip ip_tunnel xt_multiport xt_nat xt_tcpudp xt_set veth ip_vs_lc ip_set_hash_ipportnet ip_set_hash_ipport ip_set_bitmap_port ip_set_hash_ipportip ip_set dummy ip_vs_sh ip_vs_wrr ip_vs_rr ip_vs ip6table_nat ip6_tables xt_comment xt_mark xfrm4_tunnel tunnel4 ipcomp xfrm_ipcomp esp4 ah4 af_key crypto_user algif_hash xt_conntrack xt_MASQUERADE nf_conntrack_netlink nfnetlink xfrm_user xt_addrtype iptable_filter iptable_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 libcrc32c br_netfilter bridge stp llc aufs iptable_mangle bpfilter bonding dm_crypt algif_skcipher af_alg ipmi_ssif intel_rapl_msr intel_rapl_common isst_if_common skx_edac nfit x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel nls_iso8859_1 kvm crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel crypto_simd cryptd glue_helper rapl mei_me input_leds joydev mei intel_cstate ioatdma lpc_ich ipmi_si
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.293744] ipmi_devintf ipmi_msghandler acpi_pad acpi_power_meter mac_hid sch_fq_codel sunrpc ip_tables x_tables autofs4 overlay ses mgag200 enclosure drm_vram_helper scsi_transport_sas i2c_algo_bit ttm drm_kms_helper syscopyarea sysfillrect sysimgblt ixgbe fb_sys_fops hid_generic xfrm_algo usbhid uas dca i40e megaraid_sas mdio drm hid usb_storage ahci libahci wmi
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.432873] CR2: 0000000000000008
Feb 22 22:20:47 maglev-master-192-168-70-10 kernel: [14501.437117] ---[ end trace 1d44478aec8706e7 ]---