BUG: Dentry still in use [unmount of msdos loop5]

BUG: Dentry ffff88818e94c220{i=0,n=.index}  still in use (1) [unmount of msdos loop5]
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WARNING: CPU: 0 PID: 357 at fs/dcache.c:1597 umount_check+0x179/0x1c0 fs/dcache.c:1588
Modules linked in:
CPU: 0 PID: 357 Comm: syz-executor.5 Not tainted 5.4.125-syzkaller-00001-g306607c78507 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:umount_check+0x179/0x1c0 fs/dcache.c:1588
Code: ff 4c 8b 0b 48 81 c5 20 04 00 00 48 c7 c7 60 0a e9 84 4c 89 fe 4c 89 f2 4c 89 f9 45 89 e8 31 c0 55 e8 37 a2 af ff 48 83 c4 08 <0f> 0b e9 fd fe ff ff 89 e9 80 e1 07 80 c1 03 38 c1 0f 8c d4 fe ff
RSP: 0018:ffff88819bd6fc58 EFLAGS: 00010282
RAX: 0000000000000055 RBX: ffffffff85fc6160 RCX: 8047f80163e0b900
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000
RBP: ffff8881930f4420 R08: ffffffff814e90d7 R09: ffffed103edc9608
R10: ffffed103edc9608 R11: 0000000000000000 R12: dffffc0000000000
R13: 0000000000000001 R14: 0000000000000000 R15: ffff88818e94c220
FS:  00000000015f6400(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffccbd12eb8 CR3: 000000019bcd2000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 d_walk+0x2d9/0x540 fs/dcache.c:1307
 do_one_tree fs/dcache.c:1604 [inline]
 shrink_dcache_for_umount+0x8a/0x1a0 fs/dcache.c:1620
 generic_shutdown_super+0x63/0x2a0 fs/super.c:447
 kill_block_super+0x79/0xd0 fs/super.c:1444
 deactivate_locked_super+0xaf/0x100 fs/super.c:335
 deactivate_super+0x1b3/0x270 fs/super.c:366
 cleanup_mnt+0x432/0x4e0 fs/namespace.c:1102
 task_work_run+0x186/0x1b0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop arch/x86/entry/common.c:163 [inline]
 prepare_exit_to_usermode+0x2b0/0x310 arch/x86/entry/common.c:194
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x467a47
Code: ff d0 48 89 c7 b8 3c 00 00 00 0f 05 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 b8 a6 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffccbd135f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000467a47
RDX: 00007ffccbd136ca RSI: 0000000000000002 RDI: 00007ffccbd136c0
RBP: 00007ffccbd136c0 R08: 00000000ffffffff R09: 00007ffccbd13490
R10: 00000000015f7bd3 R11: 0000000000000246 R12: 00000000004bee90
R13: 00007ffccbd14790 R14: 00000000015f7b00 R15: 00007ffccbd147d0
---[ end trace 04608ae3a64cf218 ]---
VFS: Busy inodes after unmount of loop5. Self-destruct in 5 seconds.  Have a nice day...

Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Manager	Title
2021/08/09 03:24	android12-5.4	306607c78507	6972b106	.config	console log	report	info	ci2-android-5-4-kasan	BUG: Dentry still in use [unmount of msdos loop5]
2021/07/05 01:13	android12-5.4	eaef435f4357	55aa55c2	.config	console log	report	info	ci2-android-5-4-kasan	BUG: Dentry still in use [unmount of msdos loop5]
2021/04/09 21:26	android12-5.4	3b217c7fd679	6a81331a	.config	console log	report	info	ci2-android-5-4-kasan	BUG: Dentry still in use [unmount of msdos loop5]
2021/03/23 12:05	android12-5.4	c50ff8e5608b	8092f30d	.config	console log	report	info	ci2-android-5-4-kasan	BUG: Dentry still in use [unmount of msdos loop5]
2021/02/22 14:43	android12-5.4	6228b4887854	c26fb06b	.config	console log	report	info	ci2-android-5-4-kasan	BUG: Dentry still in use [unmount of msdos loop5]
2021/02/21 21:05	android12-5.4	35f4b1b90596	a659b3f1	.config	console log	report	info	ci2-android-5-4-kasan	BUG: Dentry still in use [unmount of msdos loop5]
2021/02/14 17:32	android12-5.4	0cd79a8750fa	98682e5e	.config	console log	report	info	ci2-android-5-4-kasan	BUG: Dentry still in use [unmount of msdos loop5]