Backtrace

WARNING: CPU: 2 PID: 82134 at lib/refcount.c:28 refcount_warn_saturate+0xa6/0xf0
Modules linked in: bc_3des(OE) bestcrypt(OE) uinput snd_seq_dummy snd_hrtimer xt_CHECKSUM xt_MASQUERADE xt_conntrack ipt_REJECT nf_nat_tftp nf_conntrack_tftp bridge stp llc nft_objref nf_conntrack_netbios_ns nf_conntrack_broadcast nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat ip6table_nat ip6table_mangle ip6table_raw ip6table_security iptable_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 iptable_mangle iptable_raw iptable_security ip_set rfkill nf_tables nfnetlink ip6table_filter ip6_tables iptable_filter sunrpc snd_intel8x0 snd_ac97_codec ac97_bus intel_rapl_msr intel_rapl_common snd_seq snd_seq_device rapl snd_pcm joydev snd_timer snd vboxguest i2c_piix4 soundcore pcspkr zram ip_tables vmwgfx ttm drm_kms_helper crct10dif_pclmul crc32_pclmul cec crc32c_intel drm ghash_clmulni_intel e1000 serio_raw ata_generic pata_acpi video fuse
CPU: 2 PID: 82134 Comm: bctool Tainted: G        W  OE     5.14.9-200.fc34.x86_64 #1
Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
RIP: 0010:refcount_warn_saturate+0xa6/0xf0
Code: 05 3e c6 8d 01 01 e8 0b 91 58 00 0f 0b c3 80 3d 2c c6 8d 01 00 75 95 48 c7 c7 c8 ec 62 94 c6 05 1c c6 8d 01 01 e8 ec 90 58 00 <0f> 0b c3 80 3d 0b c6 8d 01 00 0f 85 72 ff ff ff 48 c7 c7 20 ed 62
RSP: 0018:ffffa28643cefe20 EFLAGS: 00010282
RAX: 0000000000000026 RBX: ffff8e078ee93e00 RCX: 0000000000000027
RDX: ffff8e07bcd18a08 RSI: 0000000000000001 RDI: ffff8e07bcd18a00
RBP: ffff8e07038ce040 R08: 0000000000000000 R09: ffffa28643cefc58
R10: ffffa28643cefc50 R11: ffffffff94d47428 R12: ffff8e078e9a6800
R13: ffff8e0746d26478 R14: 0000000000000000 R15: 0000000000000000
FS:  00007fe3d7d07840(0000) GS:ffff8e07bcd00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055c41de3f1f8 CR3: 000000004fb98001 CR4: 00000000000706e0
Call Trace:
 disk_release+0x5b/0x80
 device_release+0x34/0x90
 kobject_put+0x7f/0x1d0
 blkdev_put+0x8e/0x1f0
 blkdev_close+0x22/0x30
 __fput+0x94/0x240
 task_work_run+0x65/0xa0
 exit_to_user_mode_prepare+0x22c/0x240
 syscall_exit_to_user_mode+0x18/0x40
 do_syscall_64+0x48/0x90
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fe3d83429b7
Code: 00 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 41 c3 48 83 ec 18 89 7c 24 0c e8 33 fc ff ff
RSP: 002b:00007fffc5bc7278 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000006 RCX: 00007fe3d83429b7
RDX: 0000000000000000 RSI: 00000000bc000020 RDI: 0000000000000005
RBP: 0000000000000000 R08: 0000000000000000 R09: 00007fe3d7f6a4e0
R10: 00007fe3d8333ca0 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000005 R14: 00000000bc000020 R15: 00007fe3d7d077a0