zdb -b crash --- dsl_deadlist_open() Aborted (core dumped)

[bud4]

System information

Type	Version/Name
Distribution Name	Ubuntu
Distribution Version	18.04.5 LTS
Linux Kernel	5.4.0-64-generic #72~18.04.1-Ubuntu
Architecture	x86_64
ZFS Version	0.8.3-1ubuntu12.5
SPL Version	0.8.3-1ubuntu12.5

Describe the problem you're observing

zdb -b lock for more time an than crash -core dumped

Describe how to reproduce the problem

zdb -b pool_z2_samba

Include any warning/errors/backtraces from the system logs

_sbin_zdb.0.crash.log
zdb -b pool_z2_samba
Traversing all blocks to verify nothing leaked ...
loading space map for vdev 4 of 5, metaslab 107 of 186 ...

771G completed (1712MB/s) estimated time remaining: 15hr 41min 48sec 0 == dmu_bonus_hold(os, object, dl, dl->dl_dbuf) (0x0 == 0x34)
ASSERT at ../../module/zfs/dsl_deadlist.c:99:dsl_deadlist_open()Aborted (core dumped)

[bud4]

process relaunched. iotop shows a lot of io made by zdb but it "loop" for hours on
futex (0x55a97f09a4b0, FUTEX_WAKE_PRIVATE, 1) = 1
it has been stalled for tens of hours without progress ; no process in state D
Traversing all blocks to verify nothing leaked ...
loading space map for vdev 4 of 5, metaslab 112 of 186 ...

I attach file with process strace
zdb_strace.log
EDIT:
after days end with this result:
leaked space: vdev 3, offset 0x2b6fc819d000, size 12288
leaked space: vdev 3, offset 0x2b6fc8fd4000, size 110592
leaked space: vdev 3, offset 0x2b6fcaf51000, size 245760
leaked space: vdev 3, offset 0x2b6fc912d000, size 12288
leaked space: vdev 3, offset 0x2b6fc81e8000, size 12288
leaked space: vdev 3, offset 0x2b6fd0810000, size 12288
leaked space: vdev 3, offset 0x2b6fd2f6d000, size 589824
leaked space: vdev 3, offset 0x2b6fd0819000, size 86016
leaked space: vdev 3, offset 0x2b6fd6def000, size 12288
leaked space: vdev 3, offset 0x2b6fd3b1f000, size 12288
leaked space: vdev 3, offset 0x2b6fd3b19000, size 12288
leaked space: vdev 3, offset 0x2b6fcfa36000, size 12288
leaked space: vdev 3, offset 0x2b6fd97f8000, size 12288
leaked space: vdev 3, offset 0x2b6fdaf77000, size 12288
leaked space: vdev 3, offset 0x2b6ff888a000, size 24576
leaked space: vdev 3, offset 0x2b6fec69b000, size 12288
leaked space: vdev 3, offset 0x2b6fde9b5000, size 380928
leaked space: vdev 3, offset 0x2b6fd6e13000, size 12288
leaked space: vdev 3, offset 0x2b6fc805c000, size 12288
leaked space: vdev 3, offset 0x2b6fb6b48000, size 36864
leaked space: vdev 3, offset 0x2b6f87d5a000, size 196608
leaked space: vdev 3, offset 0x2b6f5f368000, size 147456
leaked space: vdev 3, offset 0x2b6856f30000, size 73728
leaked space: vdev 3, offset 0x2b60a0f75000, size 86016
leaked space: vdev 3, offset 0x2b57a8667000, size 1572864
leaked space: vdev 3, offset 0x2b4913f08000, size 15532032
block traversal size 54903934058496 != alloc 102351382917120 (leaked 47447448858624)

    bp count:       559415854
    ganged count:           0
    bp logical:    66464693729792      avg: 118810
    bp physical:   50856030605312      avg:  90909     compression:   1.31
    bp allocated:  78716242120704      avg: 140711     compression:   0.84
    bp deduped:    23812308062208    ref>1: 62678679   deduplication:   1.30
    SPA allocated: 102351380324352     used: 53.50%

    additional, non-pointer bps of type 0:    6389945
    Dittoed blocks on same vdev: 20310349

[stale]

This issue has been automatically marked as "stale" because it has not had any activity for a while. It will be closed in 90 days if no further activity occurs. Thank you for your contributions.