Comment 5 for bug 1956101

Bootin with boot option break=premount:
(initramfs) modprobe zfs
[ 45.484502] spl: loading out-of-tree module taints kernel.
[ 45.503302] icp: module license 'CDDL' taints kernel.
[ 45.509218] Disabling lock debugging due to kernel taint
[ 45.709339] ZFS: Loaded module v2.1.2-1ubuntu3, ZFS pool version 5000, ZFS filesystem version 5
(initramfs) zpool import
[ 48.811749] random: crng init done
   pool: rpool
     id: 396532089768583635
  state: ONLINE
status: The pool was last accessed by another system.
 action: The pool can be imported using its name or numeric identifier and
 the '-f' flag.
   see: https://openzfs.github.io/openzfs-docs/msg/ZFS-8000-EY
 config:

 rpool ONLINE
  sda4 ONLINE

   pool: bpool
     id: 3142261943073140017
  state: ONLINE
status: Some supported features are not enabled on the pool.
 (Note that they may be intentionally disabled if the
 'compatibility' property is set.)
 action: The pool can be imported using its name or numeric identifier, though
 some features will not be available without an explicit 'zpool upgrade'.
 config:

 bpool ONLINE
  sda3 ONLINE
(initramfs) zpool import -fN rpool
(initramfs) zpool import -fN bpool
(initramfs) zpool status
  pool: bpool
 state: ONLINE
  scan: scrub repaired 0B in 00:00:55 with 0 errors on Mon Sep 12 19:50:53 2022
config:

 NAME STATE READ WRITE CKSUM
 bpool ONLINE 0 0 0
  sda3 ONLINE 0 0 0

errors: No known data errors
[ 84.038049] BUG: kernel NULL pointer dereference, address: 00000000000006c8
[ 84.046949] #PF: supervisor write access in kernel mode
[ 84.053988] #PF: error_code(0x0002) - not-present page
[ 84.060851] PGD 0 P4D 0
[ 84.065092] Oops: 0002 [#1] SMP PTI
[ 84.070315] CPU: 19 PID: 1636 Comm: zpool Tainted: P O 5.15.0-40-generic #43-Ubuntu
[ 84.081023] Hardware name: Oracle Corporation SUN FIRE X4170 M3 /MOTHER BOARD ASSEMBL , BIOS 17160400 05/06/2020
[ 84.093456] RIP: 0010:mutex_lock+0x1e/0x40
[ 84.099364] Code: c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 41 54 49 89 fc e8 2d ed ff ff 31 c0 65 48 8b 14 25 c0 fb 01 00 <f0> 49 0f b1 14 24 75 06 4c 8b 65 f8 c9 c3 4c 89 e7 e8 ac ff ff ff
[ 84.121768] RSP: 0018:ffff9fc8b7747b08 EFLAGS: 00010246
[ 84.128829] RAX: 0000000000000000 RBX: ffff8eeaa36bc000 RCX: 0000000000000000
[ 84.137866] RDX: ffff8eeab81298c0 RSI: 0000000000000000 RDI: 00000000000006c8
[ 84.146854] RBP: ffff9fc8b7747b10 R08: ffff8eea87ce49e0 R09: ffff8eea87ce49e0
[ 84.155794] R10: 0000000000000001 R11: 0000000000000000 R12: 00000000000006c8
[ 84.164788] R13: 0000000000000000 R14: 00000000000006c8 R15: 00000000000006e8
[ 84.173762] FS: 00007f5cdf0407c0(0000) GS:ffff8f019fcc0000(0000) knlGS:0000000000000000
[ 84.183673] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 84.191251] CR2: 00000000000006c8 CR3: 0000000120e28005 CR4: 00000000000606e0
[ 84.200216] Call Trace:
[ 84.204480] <TASK>
[ 84.208371] rrw_enter_read_impl+0x29/0x110 [zfs]
[ 84.215182] rrw_enter_read+0x13/0x20 [zfs]
[ 84.221387] rrw_enter+0x1d/0x20 [zfs]
[ 84.227149] dsl_pool_config_enter+0x1d/0x20 [zfs]
[ 84.233921] spa_prop_get+0x98/0x3c0 [zfs]
[ 84.239975] ? spl_kmem_free_impl+0x25/0x30 [spl]
[ 84.246462] ? spl_kmem_free_impl+0x25/0x30 [spl]
[ 84.252856] ? kfree+0x216/0x250
[ 84.257833] ? __cond_resched+0x1a/0x50
[ 84.263395] ? avl_destroy_nodes+0x9e/0xf0 [zavl]
[ 84.269820] ? __cond_resched+0x1a/0x50
[ 84.275313] ? do_raw_spin_unlock+0x9/0x10 [zfs]
[ 84.281805] ? __raw_spin_unlock+0x9/0x10 [zfs]
[ 84.288151] ? spa_deactivate+0x22b/0x320 [zfs]
[ 84.294512] ? do_raw_spin_unlock+0x9/0x10 [zfs]
[ 84.300919] ? __raw_spin_unlock+0x9/0x10 [zfs]
[ 84.307286] ? spa_name_compare+0xe/0x30 [zfs]
[ 84.313588] ? avl_find+0x6b/0xd0 [zavl]
[ 84.319107] zfs_ioc_pool_get_props+0x79/0x140 [zfs]
[ 84.325935] zfsdev_ioctl_common+0x682/0x740 [zfs]
[ 84.332567] ? __check_object_size.part.0+0x4a/0x150
[ 84.339141] ? _copy_from_user+0x2e/0x60
[ 84.344643] zfsdev_ioctl+0x57/0xe0 [zfs]
[ 84.350497] __x64_sys_ioctl+0x91/0xc0
[ 84.355800] do_syscall_64+0x5c/0xc0
[ 84.360864] ? handle_mm_fault+0xd8/0x2c0
[ 84.366387] ? do_user_addr_fault+0x1e3/0x670
[ 84.372196] ? do_syscall_64+0x69/0xc0
[ 84.377409] ? exit_to_user_mode_prepare+0x37/0xb0
[ 84.383643] ? irqentry_exit_to_user_mode+0x9/0x20
[ 84.389891] ? irqentry_exit+0x19/0x30
[ 84.395090] ? exc_page_fault+0x89/0x160
[ 84.400421] ? asm_exc_page_fault+0x8/0x30
[ 84.405911] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 84.412295] RIP: 0033:0x7f5cdf795aff
[ 84.417195] Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <41> 89 c0 3d 00 f0 ff ff 77 1f 48 8b 44 24 18 64 48 2b 04 25 28 00
[ 84.438607] RSP: 002b:00007ffe21ac8d40 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
[ 84.447548] RAX: ffffffffffffffda RBX: 000055603ed1da80 RCX: 00007f5cdf795aff
[ 84.456015] RDX: 00007ffe21ac8da0 RSI: 0000000000005a27 RDI: 0000000000000003
[ 84.464488] RBP: 00007ffe21acc380 R08: 0000000000000000 R09: 000055603ed50e20
[ 84.472977] R10: 00007f5cdf895390 R11: 0000000000000246 R12: 00007ffe21ac8da0
[ 84.481466] R13: 000055603ed0f320 R14: 0000000000001000 R15: 000055603ed1da80
[ 84.489940] </TASK>
[ 84.493418] Modules linked in: zfs(PO) zunicode(PO) zzstd(O) zlua(O) zcommon(PO) znvpair(PO) zavl(PO) icp(PO) spl(O) cdc_ether usbnet mii hid_generic usbhid hid ast i2c_algo_bit drm_vram_helper drm_ttm_helper ttm drm_kms_helper syscopyarea sysfillrect qla2xxx sysimgblt fb_sys_fops nvme_fc uas cec nvme_fabrics usb_storage ixgbe rc_core xfrm_algo nvme_core crc32_pclmul ahci i2c_i801 drm dca scsi_transport_fc libahci lpc_ich i2c_smbus megaraid_sas mdio
[ 84.539002] CR2: 00000000000006c8
[ 84.543834] ---[ end trace 287cc7541b8f3fac ]---
[ 85.478915] RIP: 0010:mutex_lock+0x1e/0x40
[ 85.483655] Code: c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 41 54 49 89 fc e8 2d ed ff ff 31 c0 65 48 8b 14 25 c0 fb 01 00 <f0> 49 0f b1 14 24 75 06 4c 8b 65 f8 c9 c3 4c 89 e7 e8 ac ff ff ff
[ 85.503753] RSP: 0018:ffff9fc8b7747b08 EFLAGS: 00010246
[ 85.509674] RAX: 0000000000000000 RBX: ffff8eeaa36bc000 RCX: 0000000000000000
[ 85.517514] RDX: ffff8eeab81298c0 RSI: 0000000000000000 RDI: 00000000000006c8
[ 85.525341] RBP: ffff9fc8b7747b10 R08: ffff8eea87ce49e0 R09: ffff8eea87ce49e0
[ 85.533182] R10: 0000000000000001 R11: 0000000000000000 R12: 00000000000006c8
[ 85.541035] R13: 0000000000000000 R14: 00000000000006c8 R15: 00000000000006e8
[ 85.548868] FS: 00007f5cdf0407c0(0000) GS:ffff8f019fcc0000(0000) knlGS:0000000000000000
[ 85.557682] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 85.564162] CR2: 00000000000006c8 CR3: 0000000120e28005 CR4: 00000000000606e0
Killed
(initramfs)