RHEL7.9 : kernel panic on sf_dentry_path/d_path

Issue

• System panic with the following backtrace :

PID: 18904    TASK: ffff9db988bb3180  CPU: 4    COMMAND: "my_process"
 #0 [ffff9dba883aeea0] machine_kexec at ffffffff85a662c4
 #1 [ffff9dba883aef00] __crash_kexec at ffffffff85b22a12
 #2 [ffff9dba883aefd0] crash_kexec at ffffffff85b22b00
 #3 [ffff9dba883aefe8] oops_end at ffffffff8618d798
 #4 [ffff9dba883af010] no_context at ffffffff85a75d14
 #5 [ffff9dba883af060] __bad_area_nosemaphore at ffffffff85a75fe2
 #6 [ffff9dba883af0b0] bad_area_nosemaphore at ffffffff85a76104
 #7 [ffff9dba883af0c0] __do_page_fault at ffffffff86190750
 #8 [ffff9dba883af130] do_page_fault at ffffffff86190975
 #9 [ffff9dba883af160] page_fault at ffffffff8618c778
    [exception RIP: d_path+144]
    RIP: ffffffff85c69680  RSP: ffff9dba883af210  RFLAGS: 00010246
    RAX: ffff9db988bb3180  RBX: ffff9dba883af260  RCX: 0000000000000000
    RDX: 0000000000001000  RSI: ffff9dbaccf6a000  RDI: ffff9dc93d172600
    RBP: ffff9dba883af240   R8: ffffffff8648edc7   R9: ffffd8214633dac0
    R10: 0000000000004ed9  R11: 0001e66a3c615281  R12: 0000000000001000
    R13: 0000000000000000  R14: ffff9dbaccf6a000  R15: ffff9db9765cc920
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
#10 [ffff9dba883af248] sf_dentry_path at ffffffffc063a86f [secfs2]
#11 [ffff9dba883af2a8] vm_os_get_proc_path at ffffffffc066e11a [secfs2]
#12 [ffff9dba883af2d0] add_backprocess at ffffffffc07962bf [secfs2]
#13 [ffff9dba883af330] vpo_audit at ffffffffc0796718 [secfs2]
#14 [ffff9dba883af420] po_chk_acc at ffffffffc077d2d4 [secfs2]
#15 [ffff9dba883af500] vm_lpo_chk at ffffffffc06a537c [secfs2]
#16 [ffff9dba883af738] check_access_r2v2 at ffffffffc06a9a24 [secfs2]
#17 [ffff9dba883af810] check_access at ffffffffc06b28de [secfs2]
#18 [ffff9dba883af960] vmfs_acc_op at ffffffffc06b5479 [secfs2]
#19 [ffff9dba883af9d8] vmfs_acc_inode at ffffffffc06b5505 [secfs2]
#20 [ffff9dba883af9f8] sfdentry_access at ffffffffc063af47 [secfs2]
#21 [ffff9dba883afa78] sffile_access at ffffffffc06405dc [secfs2]
#22 [ffff9dba883afac8] op_file_read at ffffffffc0645507 [secfs2]
#23 [ffff9dba883afbc8] cskal_call_rcu at ffffffffc042b04c [falcon_kal]
#24 [ffff9dba883afbf8] cskal_kernel_read_nosec at ffffffffc042b176 [falcon_kal]
#25 [ffff9dba883afc10] cshook_systemcalltable_pre_ia32_pread64 at ffffffffc095d208 [falcon_lsm_serviceable]
...
^C#27 [ffff9dba883afc90] _ZdlPv at ffffffffc08ffe95 [falcon_lsm_serviceable]
^C#28 [ffff9dba883afd58] _ZdlPv at ffffffffc090001a [falcon_lsm_serviceable]
^C#29 [ffff9dba883afd78] _ZdlPv at ffffffffc09000c7 [falcon_lsm_serviceable]
^C#30 [ffff9dba883afd90] cshook_security_file_free_security at ffffffffc09028cf [falcon_lsm_serviceable]
^C#31 [ffff9dba883afdb8] pinnedhook_security_file_free_security at ffffffffc050191b [falcon_lsm_pinned_14006]
#32 [ffff9dba883afdd0] security_file_free at ffffffff85d0933c
#33 [ffff9dba883afde0] __fput at ffffffff85c50844
#34 [ffff9dba883afe28] ____fput at ffffffff85c50a6e
#35 [ffff9dba883afe38] task_work_run at ffffffff85ac297b
#36 [ffff9dba883afe78] do_exit at ffffffff85aa1934
#37 [ffff9dba883aff10] do_group_exit at ffffffff85aa210f
#38 [ffff9dba883aff40] sys_exit_group at ffffffff85aa2184
#39 [ffff9dba883aff50] system_call_fastpath at ffffffff86195f92

• Another pattern of panic:

[6472346.932855] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
[6472346.932859] IP: [<ffffffff90077240>] d_path+0x90/0x150
[6472346.932867] PGD 8000000ebc560067 PUD ebc71e067 PMD ebc051067 PTE 0
[6472346.932870] Oops: 0000 [#1] SMP 
[6472346.932873] Modules linked in: btrfs raid6_pq xor vfat msdos fat ext4 mbcache jbd2 falcon_lsm_serviceable(PE) falcon_nf_netcontain(PE) falcon_kal(E) falcon_lsm_pinned_15003(E) vsock_diag unix_diag af_packet_diag netlink_diag udp_diag tcp_diag inet_diag falcon_lsm_pinned_14504(E) secvm2(POE) secfs2(POE) nfsv3 rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 nf_log_ipv6 ipt_REJECT nf_reject_ipv4 nf_log_ipv4 nf_log_common xt_LOG xt_pkttype xt_conntrack ebtable_nat ebtable_broute bridge stp llc ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat iptable_mangle iptable_security iptable_raw nf_conntrack ip_set ebtable_filter ebtables ip6table_filter
[6472346.932905]  ip6_tables iptable_filter vmw_vsock_vmci_transport vsock ppdev iosf_mbi crc32_pclmul ghash_clmulni_intel vmw_balloon aesni_intel lrw gf128mul glue_helper ablk_helper cryptd joydev pcspkr sg parport_pc parport vmw_vmci i2c_piix4 sch_fq_codel binfmt_misc nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs libcrc32c sr_mod cdrom ata_generic pata_acpi vmwgfx nfit drm_kms_helper libnvdimm sd_mod crc_t10dif syscopyarea crct10dif_generic sysfillrect sysimgblt fb_sys_fops ttm ata_piix drm libata crct10dif_pclmul crct10dif_common crc32c_intel serio_raw vmxnet3 vmw_pvscsi drm_panel_orientation_quirks dm_mirror dm_region_hash dm_log dm_mod fuse [last unloaded: falcon_kal]
[6472346.932934] CPU: 1 PID: 1313 Comm: sonOutThreadPoo Kdump: loaded Tainted: P           OE  ------------   3.10.0-1160.83.1.el7.x86_64 #1
[6472346.932936] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020
[6472346.932938] task: ffff96eefdaf9080 ti: ffff96e26f324000 task.ti: ffff96e26f324000
[6472346.932940] RIP: 0010:[<ffffffff90077240>]  [<ffffffff90077240>] d_path+0x90/0x150
[6472346.932943] RSP: 0018:ffff96e26f327060  EFLAGS: 00010246
[6472346.932944] RAX: ffff96eefdaf9080 RBX: ffff96e26f3270b0 RCX: 0000000000000000
[6472346.932945] RDX: 0000000000001000 RSI: ffff96edfe63f000 RDI: ffff96df35806600
[6472346.932947] RBP: ffff96e26f327090 R08: ffffffff9088fe6f R09: ffffe708fbf99000
[6472346.932948] R10: 0000000000004f98 R11: 0001bd6a46a15281 R12: 0000000000001000
[6472346.932950] R13: 0000000000000000 R14: ffff96edfe63f000 R15: ffff96eef84e2620
[6472346.932953] FS:  00007f96bc0c4700(0000) GS:ffff96ef3fc80000(0000) knlGS:0000000000000000
[6472346.932955] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[6472346.932956] CR2: 0000000000000008 CR3: 0000000fd12b6000 CR4: 00000000007607e0
[6472346.932983] PKRU: 55555554
[6472346.932984] Call Trace:
[6472346.933021]  [<ffffffffc096e09f>] sf_dentry_path+0x11f/0x1d0 [secfs2]
[6472346.933036]  [<ffffffffc09a236d>] vm_os_get_ppid_info+0xcd/0x3c0 [secfs2]
[6472346.933060]  [<ffffffffc0ad8c40>] add_backprocess+0x60/0x1e0 [secfs2]
[6472346.933064]  [<ffffffff901a9fe9>] ? snprintf+0x49/0x70
[6472346.933087]  [<ffffffffc0ad90f7>] ? vpo_audit+0x337/0x1000 [secfs2]
[6472346.933108]  [<ffffffffc0ac00f4>] ? po_chk_acc+0x6b4/0xe90 [secfs2]
[6472346.933132]  [<ffffffffc0a6003b>] ? cache_search+0xfb/0x140 [secfs2]
[6472346.933151]  [<ffffffffc0ab68ea>] ? get_name+0x2a/0x320 [secfs2]
[6472346.933170]  [<ffffffffc09dbe9c>] ? vm_lpo_chk+0xc2c/0x1280 [secfs2]
[6472346.933173]  [<ffffffff9019f799>] ? kobject_add_internal+0x189/0x320
[6472346.933190]  [<ffffffffc09d4660>] ? kpr_cleanup_keys+0x110/0x110 [secfs2]
[6472346.933206]  [<ffffffffc09d4db0>] ? kpr_write_file+0xe0/0xe0 [secfs2]
[6472346.933221]  [<ffffffffc09d46d0>] ? kpr_is_kp_enabled+0x30/0x30 [secfs2]
[6472346.933237]  [<ffffffffc09d4850>] ? kpr_rkey_preprocess_key+0x180/0x180 [secfs2]
[6472346.933258]  [<ffffffffc0a720a0>] ? do_aria_speed_test+0x370/0x370 [secfs2]
[6472346.933274]  [<ffffffffc09d90c0>] ? sig_file_read+0x220/0x220 [secfs2]
[6472346.933290]  [<ffffffffc09d7a20>] ? cache_hash_cb+0x50/0x50 [secfs2]
[6472346.933305]  [<ffffffffc09d7b70>] ? vm_lpo_get_tag+0x40/0x40 [secfs2]
[6472346.933320]  [<ffffffffc09d7a50>] ? policyname+0x30/0x30 [secfs2]
[6472346.933335]  [<ffffffffc09d7b30>] ? vm_get_key_type+0x60/0x60 [secfs2]
[6472346.933358]  [<ffffffffc0a5c920>] ? vm_tag_event_worker+0x3e0/0x3e0 [secfs2]
[6472346.933375]  [<ffffffffc09e0504>] ? check_access_r2v2+0x114/0x180 [secfs2]
[6472346.933400]  [<ffffffffc0a0972b>] ? vmfs_po_xfable+0x4b/0x160 [secfs2]
[6472346.933421]  [<ffffffffc0a098a3>] ? vmfs_rekey_check_access+0x63/0x110 [secfs2]
[6472346.933440]  [<ffffffffc09e8b12>] ? check_access+0x17e2/0x1b80 [secfs2]
[6472346.933459]  [<ffffffffc09eb229>] ? vmfs_acc_op+0xd9/0x140 [secfs2]
[6472346.933476]  [<ffffffffc09eb2b5>] ? vmfs_acc_inode+0x25/0x40 [secfs2]
[6472346.933488]  [<ffffffffc096e777>] ? sfdentry_access+0xe7/0x1d0 [secfs2]
[6472346.933491]  [<ffffffff8ffd3dc4>] ? __alloc_pages_nodemask+0x184/0xbf0
[6472346.933503]  [<ffffffffc0979cac>] ? sffile_access+0xdc/0x150 [secfs2]
[6472346.933515]  [<ffffffffc0980101>] ? op_file_read+0x571/0xea0 [secfs2]
[6472346.933518]  [<ffffffff90010320>] ? vmap_page_range_noflush+0x2c0/0x3f0
[6472346.933521]  [<ffffffffc089a55c>] ? 0xffffffffc089a55b
[6472346.933522]  [<ffffffffc089a686>] ? 0xffffffffc089a685
[6472346.933526]  [<ffffffffc0ddcce8>] ? cshook_systemcalltable_pre_compat_sys_ioctl+0x29aa8/0x320b0 [falcon_lsm_serviceable]
[6472346.933529]  [<ffffffffc0d739cf>] ? _ZdlPv+0x4055f/0x41980 [falcon_lsm_serviceable]
[6472346.933531]  [<ffffffffc0d73bc1>] ? _ZdlPv+0x40751/0x41980 [falcon_lsm_serviceable]
[6472346.933535]  [<ffffffff900354a0>] ? __kmalloc+0x1d0/0x240
[6472346.933536]  [<ffffffffc08998be>] ? 0xffffffffc08998bd
[6472346.933538]  [<ffffffffc0d73d4a>] ? _ZdlPv+0x408da/0x41980 [falcon_lsm_serviceable]
[6472346.933541]  [<ffffffffc0d73df7>] ? _ZdlPv+0x40987/0x41980 [falcon_lsm_serviceable]
[6472346.933543]  [<ffffffffc0d768a5>] ? cshook_security_file_free_security+0x135/0x59e0 [falcon_lsm_serviceable]
[6472346.933548]  [<ffffffffc0bd29fb>] ? pinnedhook_security_file_free_security+0x3b/0x60 [falcon_lsm_pinned_15003]
[6472346.933551]  [<ffffffff9011acec>] ? security_file_free+0x1c/0x30
[6472346.933553]  [<ffffffff9005db94>] ? __fput+0xf4/0x230
[6472346.933555]  [<ffffffff9005ddbe>] ? ____fput+0xe/0x20
[6472346.933558]  [<ffffffff8fec7e5b>] ? task_work_run+0xbb/0xe0
[6472346.933561]  [<ffffffff8fea6164>] ? do_exit+0x2d4/0xa30
[6472346.933565]  [<ffffffff90080794>] ? mntput+0x24/0x40
[6472346.933567]  [<ffffffff9005dc39>] ? __fput+0x199/0x230
[6472346.933569]  [<ffffffff8fea693f>] ? do_group_exit+0x3f/0xa0
[6472346.933573]  [<ffffffff8feb814e>] ? get_signal_to_deliver+0x1ce/0x5e0
[6472346.933577]  [<ffffffff8fe2d5b7>] ? do_signal+0x57/0x6f0
[6472346.933580]  [<ffffffff8fec7d19>] ? task_work_add+0x59/0x70
[6472346.933582]  [<ffffffff8fe2dcca>] ? do_notify_resume+0x7a/0xd0
[6472346.933585]  [<ffffffff905c56f7>] ? int_signal+0x12/0x17
[6472346.933587] Code: 00 48 83 c4 28 5b 5d c3 cc cc cc cc 0f 1f 80 00 00 00 00 48 8b 03 48 3b 38 75 cc 65 48 8b 04 25 c0 0e 01 00 48 8b 88 50 07 00 00 <8b> 71 08 40 f6 c6 01 0f 85 a9 00 00 00 48 8b 41 18 48 8b 51 20 
[6472346.933607] RIP  [<ffffffff90077240>] d_path+0x90/0x150
[6472346.933610]  RSP <ffff96e26f327060>
[6472346.933611] CR2: 0000000000000008