Server crashes with BUG: unable to handle kernel paging request at 0000776500007852 in the code path of third party module "gc_enforcement"

Diagnostic Steps

• Server crashed due to [gc_enforcement] module function as shown below,

Kernel ring buffer:

crash> log
BUG: unable to handle kernel paging request at 0000776500007852
IP: [<ffffffffa087d605>] endr_port_table_find_explicit_rcu+0x195/0x4a0 [gc_enforcement]  <<-------
Call Trace:
 <IRQ> 
 [<ffffffffa087d93f>] endr_port_table_find_task+0x2f/0x100 [gc_enforcement]
 [<ffffffffa085e109>] ? _endr_sm_process_packet_do+0xc9/0x7f40 [gc_enforcement]
 [<ffffffffa082f32c>] endr_sysctl_init+0x2bc/0x2550 [gc_enforcement]
 [<ffffffff814ff9d5>] ? inet_addr_type+0xa5/0x130
 [<ffffffff814caa2f>] ? __ip_local_out+0x9f/0xb0
 [<ffffffff81013ec3>] ? native_sched_clock+0x13/0x80
 [<ffffffff81013479>] ? sched_clock+0x9/0x10
 [<ffffffffa08375b9>] ? endr_trace_clock+0x9/0x10 [gc_enforcement]
 [<ffffffffa0865ff0>] ? endr_sm_process_packet_do+0x70/0x120 [gc_enforcement]
 [<ffffffffa083369b>] endr_nf_init+0x1ddb/0x44a0 [gc_enforcement]
 [<ffffffffa015815f>] ? addrtype_mt_v1+0xdf/0x110 [ipt_addrtype]
 [<ffffffffa01dc115>] ? ipt_do_table+0x295/0x680 [ip_tables]
 [<ffffffffa0319bf4>] ? nf_ct_invert_tuple+0x84/0xa0 [nf_conntrack]
 [<ffffffffa031accd>] ? nf_conntrack_tuple_taken+0x14d/0x160 [nf_conntrack]
 [<ffffffffa0835f07>] _endr_nfhook_in+0x17/0x20 [gc_enforcement]
 [<ffffffffa0835f83>] endr_nfhook_in+0x73/0x170 [gc_enforcement]
 [<ffffffffa083607c>] endr_nfhook_in+0x16c/0x170 [gc_enforcement]
 [<ffffffff814ba02f>] nf_iterate+0x6f/0xb0
 [<ffffffff814c5120>] ? ip_local_deliver_finish+0x0/0x2d0
 [<ffffffff814ba1e6>] nf_hook_slow+0x76/0x120
 [<ffffffff814c5120>] ? ip_local_deliver_finish+0x0/0x2d0
 [<ffffffff814c544a>] ip_local_deliver+0x5a/0xa0
 [<ffffffff814c4923>] ip_rcv_finish+0x133/0x460
 [<ffffffff814c4ec8>] ip_rcv+0x278/0x360
 [<ffffffff814891f3>] __netif_receive_skb+0x203/0x590
 [<ffffffff8148d0d8>] netif_receive_skb+0x58/0x60

Backtrace of panic task:

• The server panicked in the function endr_port_table_find_explicit_rcu().

crash> bt 
PID: 0        TASK: ffff88043989a040  CPU: 2    COMMAND: "swapper"
 #0 [ffff880038083270] machine_kexec+0x18b at ffffffff8104111b
 #1 [ffff8800380832d0] crash_kexec+0x72 at ffffffff810d6932
 #2 [ffff8800380833a0] oops_end+0xc0 at ffffffff8155e310
 #3 [ffff8800380833d0] no_context+0xfb at ffffffff810546bb
 #4 [ffff880038083420] __bad_area_nosemaphore+0x125 at ffffffff81054945
 #5 [ffff880038083470] bad_area_nosemaphore+0x13 at ffffffff81054a13
 #6 [ffff880038083480] __do_page_fault+0x30c at ffffffff8105512c
 #7 [ffff8800380835a0] do_page_fault+0x3e at ffffffff815602ce
 #8 [ffff8800380835d0] page_fault+0x25 at ffffffff8155d265
    [exception RIP: endr_port_table_find_explicit_rcu+405]    <<-------
    RIP: ffffffffa087d605  RSP: ffff880038083680  RFLAGS: 00010202
    RAX: 0000000000050f58  RBX: 00007765000077ea  RCX: 00000000d39351b8
    RDX: 000000002b90beee  RSI: ffff8800380836a0  RDI: 00000000f0000072
    RBP: ffff880038083760   R8: 000000000000da6e   R9: 0000000000000000
    R10: 000000003a75496e  R11: 000000003ecd5a0a  R12: 0000000000000000
    R13: 000000000a0c39fa  R14: 0000000000000000  R15: 000000000a0c2d40
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #9 [ffff880038083768] endr_port_table_find_task+0x2f at ffffffffa087d93f [gc_enforcement]
#10 [ffff880038083798] endr_sysctl_init+0x2bc at ffffffffa082f32c [gc_enforcement]
#11 [ffff8800380838e8] endr_nf_init+0x1ddb at ffffffffa083369b [gc_enforcement]
#12 [ffff880038083aa8] _endr_nfhook_in+0x17 at ffffffffa0835f07 [gc_enforcement]
#13 [ffff880038083ab8] endr_nfhook_in+0x73 at ffffffffa0835f83 [gc_enforcement]
#14 [ffff880038083b08] endr_nfhook_in+0x16c at ffffffffa083607c [gc_enforcement]
#15 [ffff880038083b68] nf_hook_slow+0x76 at ffffffff814ba1e6
#16 [ffff880038083be8] ip_local_deliver+0x5a at ffffffff814c544a
#17 [ffff880038083c18] ip_rcv_finish+0x133 at ffffffff814c4923
#18 [ffff880038083c58] ip_rcv+0x278 at ffffffff814c4ec8
#19 [ffff880038083c98] __netif_receive_skb+0x203 at ffffffff814891f3
#20 [ffff880038083ce8] netif_receive_skb+0x58 at ffffffff8148d0d8
#21 [ffff880038083d28] napi_skb_finish+0x50 at ffffffff8148d1e0
#22 [ffff880038083d48] napi_gro_receive+0x39 at ffffffff8148d7f9
#23 [ffff880038083d68] vmxnet3_rq_rx_complete+0x6eb at ffffffffa017972b [vmxnet3]
#24 [ffff880038083e18] vmxnet3_poll_rx_only+0x43 at ffffffffa0179fc3 [vmxnet3]
#25 [ffff880038083e58] net_rx_action+0x109 at ffffffff8148ed59
#26 [ffff880038083eb8] __do_softirq+0xea at ffffffff8108994a
#27 [ffff880038083f38] call_softirq+0x1c at ffffffff8156591c
#28 [ffff880038083f50] do_softirq+0x65 at ffffffff8100e4c5
#29 [ffff880038083f70] irq_exit+0x8d at ffffffff810895dd
#30 [ffff880038083f80] do_IRQ+0x75 at ffffffff81566795

Dis-assembly of exception RIP:

crash> sym endr_port_table_find_explicit_rcu
ffffffffa087d470 (t) endr_port_table_find_explicit_rcu [gc_enforcement]
                                         ^                     ^
                                         |                     |
                [ Function within the module code ]      [ Module Name ]

Third-party modules:

• Details of an unsigned (U) module: [gc_enforcement].

crash> mod -t | grep -i 'gc_enforcement'
gc_enforcement           (U)  <<-------
crash>