INFO: task syz-executor.4:9641 can't die for more than 143 seconds.
task:syz-executor.4  state:D stack:27312 pid: 9641 ppid:  6652 flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:4987 [inline]
 __schedule+0xa9a/0x4940 kernel/sched/core.c:6268
 schedule+0xd2/0x260 kernel/sched/core.c:6341
 blk_mq_freeze_queue_wait+0x112/0x160 block/blk-mq.c:178
 __loop_clr_fd+0x1ae/0x1070 drivers/block/loop.c:1122
 loop_clr_fd drivers/block/loop.c:1237 [inline]
 lo_ioctl+0x398/0x17c0 drivers/block/loop.c:1562
 blkdev_ioctl+0x37a/0x800 block/ioctl.c:609
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl fs/ioctl.c:860 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fa88602f8a7
RSP: 002b:00007fa8835a4fa8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000020000200 RCX: 00007fa88602f8a7
RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000004
RBP: 00007fa8835a56bc R08: 00007fa8835a5040 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000246 R12: ffffffffffffffff
R13: 0000000000000005 R14: 00007fa8835a5000 R15: 0000000020010800
 </TASK>
INFO: task syz-executor.4:9641 blocked for more than 143 seconds.
      Not tainted 5.16.0-rc1-next-20211118-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.4  state:D stack:27312 pid: 9641 ppid:  6652 flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:4987 [inline]
 __schedule+0xa9a/0x4940 kernel/sched/core.c:6268
 schedule+0xd2/0x260 kernel/sched/core.c:6341
 blk_mq_freeze_queue_wait+0x112/0x160 block/blk-mq.c:178
 __loop_clr_fd+0x1ae/0x1070 drivers/block/loop.c:1122
 loop_clr_fd drivers/block/loop.c:1237 [inline]
 lo_ioctl+0x398/0x17c0 drivers/block/loop.c:1562
 blkdev_ioctl+0x37a/0x800 block/ioctl.c:609
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl fs/ioctl.c:860 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fa88602f8a7
RSP: 002b:00007fa8835a4fa8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000020000200 RCX: 00007fa88602f8a7
RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000004
RBP: 00007fa8835a56bc R08: 00007fa8835a5040 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000246 R12: ffffffffffffffff
R13: 0000000000000005 R14: 00007fa8835a5000 R15: 0000000020010800
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8bb83ba0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458
2 locks held by systemd-udevd/2970:
 #0: ffff88801a7f6918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev.part.0+0x9b/0xb50 block/bdev.c:819
 #1: ffff88801a7f2360 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_open+0x75/0x120 drivers/block/loop.c:1733
1 lock held by in:imklog/6230:
 #0: ffff88807af060f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990
1 lock held by syz-executor.4/9641:
 #0: ffff88801a7f2360 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x7a/0x1070 drivers/block/loop.c:1106

=============================================

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.16.0-rc1-next-20211118-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:254 [inline]
 watchdog+0xcb7/0xed0 kernel/hung_task.c:339
 kthread+0x405/0x4f0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 2967 Comm: systemd-journal Not tainted 5.16.0-rc1-next-20211118-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0033:0x556b4de53430
Code: fd ff ff 0f 83 10 f2 ff ff 48 8d 0d 6a e4 00 00 48 8d 35 33 ac 00 00 48 8d 3d 31 d3 00 00 ba 01 04 00 00 e8 72 b0 ff ff 66 90 <4c> 8b a5 b8 fd ff ff e9 7a f2 ff ff 0f 1f 40 00 c7 85 9c fd ff ff
RSP: 002b:00007fff7556b730 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 000000000000000e
RDX: 000000000000001c RSI: 00007fff7556bbb0 RDI: 00007fff7556e5a0
RBP: 00007fff7556b9c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000069 R11: 00000000ffffffff R12: 0000000000000000
R13: 00007fff7556e5a0 R14: 00007fff7556e5a0 R15: 00007fff7556bbb0
FS:  00007f1f3c99a8c0 GS:  0000000000000000