INFO: task syz.2.5818:12701 blocked for more than 143 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.5818      state:D stack:28184 pid:12701 tgid:12700 ppid:11245  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x14ef/0x4fb0
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x829/0x1340
 comedi_open+0xc0/0x5e0
 chrdev_open+0x4cd/0x5e0
 do_dentry_open+0x7ce/0x1420
 vfs_open+0x3b/0x340
 path_openat+0x3486/0x3e20
 do_filp_open+0x22d/0x490
 do_sys_openat2+0x12f/0x220
 __x64_sys_openat+0x138/0x170
 do_syscall_64+0xe2/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f545c59acb9
RSP: 002b:00007f545d41e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f545c815fa0 RCX: 00007f545c59acb9
RDX: 0000000000080c02 RSI: 0000200000000080 RDI: ffffffffffffff9c
RBP: 00007f545c608bf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f545c816038 R14: 00007f545c815fa0 R15: 00007ffebe802c38
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/35:
 #0: ffffffff8e341ae0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by kworker/u10:12/3492:
 #0: ffff888101bce948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0
 #1: ffffc90021a77bc0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0
2 locks held by kworker/u9:12/4184:
2 locks held by getty/6442:
 #0: ffff888112a8e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900053712f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0
1 lock held by syz.8.3305/27648:
1 lock held by syz.2.5818/12701:
 #0: ffff88810f8fc0f8 (&dev->mutex#4){+.+.}-{4:4}, at: comedi_open+0xc0/0x5e0

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 35 Comm: khungtaskd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150
 nmi_cpu_backtrace+0x274/0x2d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 sys_info+0x135/0x170
 watchdog+0xf90/0xfe0
 kthread+0x726/0x8b0
 ret_from_fork+0x51b/0xa40
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 18324 Comm: syz.5.7333 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:free_frozen_page_commit+0x430/0x1290
Code: 8d 7e 4c 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 89 6c 24 30 0f 85 da 07 00 00 45 8b 5e 4c 49 8d 7e 44 49 89 fa 49 c1 ea 03 <43> 0f b6 04 2a 84 c0 44 89 5c 24 34 0f 85 fd 07 00 00 8b 07 44 39
RSP: 0000:ffffc900070cf0c0 EFLAGS: 00000a07
RAX: 0000000000000000 RBX: 1ffff110478c81ea RCX: 0000000000000000
RDX: 000000000000003f RSI: ffff88823c640f40 RDI: ffff88823c640f44
RBP: 00000000000007e0 R08: ffff88823c640f58 R09: 0000000000002259
R10: 1ffff110478c81e8 R11: 000000000000db67 R12: 0000000000000000
R13: dffffc0000000000 R14: ffff88823c640f00 R15: ffff88823c640f54
FS:  00007f5a9be6a6c0(0000) GS:ffff8882a9a09000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffffffe70 CR3: 000000000e13a000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 free_unref_folios+0xfe9/0x13c0
 folios_put_refs+0x58a/0x680
 shmem_undo_range+0x529/0x1570
 shmem_evict_inode+0x240/0x9e0
 evict+0x61e/0xb10
 __dentry_kill+0x209/0x660
 finish_dput+0xc9/0x480
 __fput+0x691/0xa70
 task_work_run+0x1d9/0x270
 do_exit+0x893/0x25c0
 do_group_exit+0x21b/0x2d0
 get_signal+0x1284/0x1330
 arch_do_signal_or_restart+0xbc/0x830
 irqentry_exit+0x175/0x610
 asm_exc_page_fault+0x26/0x30
RIP: 0033:0x7f5a9af9acc1
Code: Unable to access opcode bytes at 0x7f5a9af9ac97.
RSP: 002b:fffffffffffffe70 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f5a9b215fa0 RCX: 00007f5a9af9acb9
RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000
RBP: 00007f5a9b008bf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f5a9b216038 R14: 00007f5a9b215fa0 R15: 00007ffe3bea4288
 </TASK>
