BUG: Dentry ffff8881e5e53550{i=0,n=.index}  still in use (1) [unmount of fuse fuse]
------------[ cut here ]------------
WARNING: CPU: 0 PID: 350 at fs/dcache.c:1597 umount_check+0x179/0x1c0 fs/dcache.c:1588
Modules linked in:
CPU: 0 PID: 350 Comm: syz-executor.1 Not tainted 5.4.125-syzkaller-00012-ge7e1f9adf836 #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 a0 0c 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:ffff88819f69fb30 EFLAGS: 00010296
RAX: 0000000000000053 RBX: ffffffff85fde060 RCX: a41038ba9239e300
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000
RBP: ffff8881e35b2420 R08: ffffffff814e90d7 R09: ffffed103edc9608
R10: ffffed103edc9608 R11: 0000000000000000 R12: dffffc0000000000
R13: 0000000000000001 R14: 0000000000000000 R15: ffff8881e5e53550
FS:  0000000002f96400(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000002f9fb38 CR3: 000000019f666000 CR4: 00000000001406f0
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_anon_super+0x36/0x60 fs/super.c:1108
 fuse_kill_sb_anon+0x1c0/0x280 fs/fuse/inode.c:1378
 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:00007ffe1a5d6ef8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000467a47
RDX: 00007ffe1a5d6fca RSI: 0000000000000002 RDI: 00007ffe1a5d6fc0
RBP: 00007ffe1a5d6fc0 R08: 00000000ffffffff R09: 00007ffe1a5d6d90
R10: 0000000002f97bd3 R11: 0000000000000246 R12: 00000000004bee90
R13: 00007ffe1a5d8090 R14: 0000000002f97b00 R15: 00007ffe1a5d80d0
---[ end trace 561bc79d5ea8d8ba ]---
BUG: Dentry ffff8881e5e53550{i=0,n=.index}  still in use (1) [unmount of fuse fuse]
------------[ cut here ]------------
WARNING: CPU: 1 PID: 350 at fs/dcache.c:1597 umount_check+0x179/0x1c0 fs/dcache.c:1588
Modules linked in:
CPU: 1 PID: 350 Comm: syz-executor.1 Tainted: G        W         5.4.125-syzkaller-00012-ge7e1f9adf836 #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 a0 0c 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:ffff88819f69fb30 EFLAGS: 00010296
RAX: 0000000000000053 RBX: ffffffff85fde060 RCX: a41038ba9239e300
RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000000
RBP: ffff8881e35b2420 R08: ffffffff814e90d7 R09: ffffed103ede9608
R10: ffffed103ede9608 R11: 0000000000000000 R12: dffffc0000000000
R13: 0000000000000001 R14: 0000000000000000 R15: ffff8881e5e53550
FS:  0000000002f96400(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4f60e83718 CR3: 000000019f666000 CR4: 00000000001406e0
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_anon_super+0x36/0x60 fs/super.c:1108
 fuse_kill_sb_anon+0x1c0/0x280 fs/fuse/inode.c:1378
 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:00007ffe1a5d6ef8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000467a47
RDX: 00007ffe1a5d6fca RSI: 0000000000000002 RDI: 00007ffe1a5d6fc0
RBP: 00007ffe1a5d6fc0 R08: 00000000ffffffff R09: 00007ffe1a5d6d90
R10: 0000000002f97bd3 R11: 0000000000000246 R12: 00000000004bee90
R13: 00007ffe1a5d8090 R14: 0000000002f97b00 R15: 00007ffe1a5d80d0
---[ end trace 561bc79d5ea8d8bb ]---
VFS: Busy inodes after unmount of fuse. Self-destruct in 5 seconds.  Have a nice day...