Kernel panic in convert_raw_inode() or convert_inode() due to a NULL pointer dereference

Issue

• Kernel panic in the convert_raw_inode() function due to a NULL pointer dereference:

[ 5251.514600] BUG: unable to handle kernel NULL pointer dereference at 0000000000000040
[ 5251.514723] PGD 0 P4D 0 
[ 5251.514767] Oops: 0000 [#1] SMP PTI
[ 5251.514782] CPU: 3 PID: 2806 Comm: EventPipeline Kdump: loaded Tainted: POE  -----------  4.18.0-305.25.1.el8_4.x86_64 #1
[ 5251.514847] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 05/28/2020
[ 5251.515015] RIP: 0010:convert_raw_inode+0x43/0x27c [b9k_87611]
[ 5251.515044] Code: 00 48 89 45 f8 31 c0 bf 48 30 00 00 e8 07 43 ff ff 48 89 45 c8 48 83 7d c8 00 75 0a b8 00 00 00 00 e9 27 02 00 00 48 8b 45 b8 <48> 8b 50 40 48 8b 45 c8 48 89 10 48 8b 45 b8 8b 50 04 48 8b 45 c8
[ 5251.515094] RSP: 0018:ffffb382c4107d28 EFLAGS: 00010286
[ 5251.515111] RAX: 0000000000000000 RBX: ffffffffc0bed600 RCX: 00000000c001c0de
[ 5251.515131] RDX: 0000000000000001 RSI: 0000000000000001 RDI: 0000000000000286
[ 5251.515152] RBP: ffffb382c4107d70 R08: 0000000000030620 R09: 0000000000000006
[ 5251.515172] R10: 0000000000000002 R11: 0000000000000000 R12: 0000000000000000
[ 5251.515192] R13: ffff934a84316b88 R14: ffff934ea5588020 R15: ffff934e24e73380
[ 5251.515213] FS:  00007f2ab4d7c700(0000) GS:ffff934eaf8c0000(0000) knlGS:0000000000000000
[ 5251.515236] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 5251.515253] CR2: 0000000000000040 CR3: 000000041f614001 CR4: 00000000003706e0
[ 5251.515327] Call Trace:
[ 5251.515345]  ? security_file_free+0x1/0x30
[ 5251.515389]  convert_inode_dentry+0x39/0x35d [b9k_87611]
[ 5251.515436]  convert_inode+0x90/0xac [b9k_87611]
[ 5251.515535]  get_vnode_from_file+0x5f/0x105 [b9k_87611]
[ 5251.515582]  cbp_lsm_mmap_file+0x31a/0x480 [b9k_87611]
[ 5251.515603]  cbstub_lsm_file_free_security+0x7f/0x8e [cbproxy_cbp_876_20211111]
[ 5251.515626]  security_file_free+0x22/0x30
[ 5251.515641]  __fput+0x12c/0x250
[ 5251.515655]  task_work_run+0x8a/0xb0
[ 5251.516245]  exit_to_usermode_loop+0xeb/0xf0
[ 5251.516845]  do_syscall_64+0x198/0x1a0
[ 5251.517410]  entry_SYSCALL_64_after_hwframe+0x65/0xca
[ 5251.518012] RIP: 0033:0x7f2ab669e977
[ 5251.518538] Code: 12 b8 03 00 00 00 0f 05 48 3d 00 f0 ff ff 77 3b c3 66 90 53 89 fb 48 83 ec 10 e8 e4 fb ff ff 89 df 89 c2 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 2b 89 d7 89 44 24 0c e8 26 fc ff ff 8b 44 24
[ 5251.519713] RSP: 002b:00007f2ab4d7baa0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
[ 5251.520302] RAX: 0000000000000000 RBX: 0000000000000017 RCX: 00007f2ab669e977
[ 5251.520898] RDX: 0000000000000000 RSI: 00007f2ab4d7bb60 RDI: 0000000000000017
[ 5251.521492] RBP: 00007f2ab4d7bad0 R08: 0000000000000000 R09: 0000000000001067
[ 5251.522102] R10: 0000000000000000 R11: 0000000000000293 R12: 00007f2aac7fabb0
[ 5251.522695] R13: 00007f2ab4d7bc6c R14: 00007f2ab4d7bb20 R15: 0000000000000017
[ 5251.523311] Modules linked in: nf_conntrack_netlink nft_counter nft_log binfmt_misc b9k_87611(POE) ..
[ 5251.527637] Features: eBPF/event
[ 5251.528405] CR2: 0000000000000040

• Kernel panic in the convert_inode() function due to a NULL pointer dereference:

[ 1560.105207] BUG: unable to handle kernel NULL pointer dereference at 0000000000000140
[ 1560.106363] PGD 0 P4D 0 
[ 1560.106738] Oops: 0000 [#1] SMP NOPTI
[ 1560.107110] CPU: 24 PID: 2424 Comm: EventPipeline Kdump: loaded Tainted: POE  ----------- 4.18.0-305.10.2.el8_4.x86_64 #1
[ 1560.107879] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020
[ 1560.108766] RIP: 0010:convert_inode+0x1d/0xac [b9k_87611]
[ 1560.109198] Code: 28 00 00 00 74 05 e8 3b dd 0d f7 c9 c3 0f 1f 44 00 00 55 48 89 e5 48 83 ec 28 48 89 7d d8 48 c7 45 e8 00 00 00 00 48 8b 45 d8 <48> 8b 80 40 01 00 00 48 89 45 e0 eb 35 48 8b 45 e0 48 89 45 f0 48
[ 1560.110569] RSP: 0018:ffffb42210a7fdc8 EFLAGS: 00010292
[ 1560.111124] RAX: 0000000000000000 RBX: ffffffffc0cd7600 RCX: ffffffffc10b4bd0
[ 1560.111625] RDX: ffffffffc10b1652 RSI: 0000000000000001 RDI: 0000000000000000
[ 1560.112121] RBP: ffffb42210a7fdf0 R08: 0000000000000000 R09: 0000000000000000
[ 1560.112624] R10: ffffb42210a7fea8 R11: ffff9b482031e910 R12: 0000000000000000
[ 1560.113120] R13: ffff9b466fce6fc8 R14: ffff9b482a90b620 R15: ffff9b440c0f46c0
[ 1560.113610] FS:  00007f0810977700(0000) GS:ffff9b4844400000(0000) knlGS:0000000000000000
[ 1560.114106] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1560.114609] CR2: 0000000000000140 CR3: 0000000df3cb2005 CR4: 00000000003706e0
[ 1560.115130] Call Trace:
[ 1560.115687]  ? ShouldExcludeNetworkOperation+0x1b/0x1d7 [b9k_87611]
[ 1560.116269]  get_vnode_from_file+0x5f/0x105 [b9k_87611]
[ 1560.116804]  cbp_lsm_mmap_file+0x31a/0x480 [b9k_87611]
[ 1560.117309]  cbstub_lsm_file_free_security+0x7f/0x8e [cbproxy_cbp_876_20211111]
[ 1560.117904]  security_file_free+0x22/0x30
[ 1560.118412]  __fput+0x12c/0x250
[ 1560.118914]  task_work_run+0x8a/0xb0
[ 1560.119408]  exit_to_usermode_loop+0xeb/0xf0
[ 1560.119922]  do_syscall_64+0x198/0x1a0
[ 1560.120408]  entry_SYSCALL_64_after_hwframe+0x65/0xca
[ 1560.120893] RIP: 0033:0x7f08112661cf
[ 1560.121363] Code: 00 0f 05 48 3d 00 f0 ff ff 77 40 c3 0f 1f 80 00 00 00 00 53 89 fb 48 83 ec 10 e8 fc c3 01 00 89 df 89 c2 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 2b 89 d7 89 44 24 0c e8 3e c4 01 00 8b 44 24
[ 1560.122841] RSP: 002b:00007f0810976a00 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
[ 1560.123348] RAX: 0000000000000000 RBX: 0000000000000006 RCX: 00007f08112661cf
[ 1560.123846] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000006
[ 1560.124346] RBP: 00007f0810976a60 R08: 0000000000000000 R09: 00007f081297e61a
[ 1560.124845] R10: 00007f0810976a60 R11: 0000000000000293 R12: 0000000000000006
[ 1560.125341] R13: 00007f0812a839d0 R14: 00007f08109775d8 R15: 000000000000000
[ 1560.125822] Modules linked in: iscsi_target_mod target_core_mod bmhook(OE) ...
[ 1560.133000] Features: eBPF/event xt_u32
[ 1560.133550] CR2: 0000000000000140