INFO: task syz.4.3424:20996 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.3424      state:D stack:24648 pid:20996 tgid:20995 ppid:20487  task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 wb_wait_for_completion+0x15f/0x260
 sync_inodes_sb+0x1bb/0xa10
 __iterate_supers+0x13d/0x290
 ksys_sync+0x94/0x150
 __ia32_sys_sync+0xe/0x20
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f78a098ebe9
RSP: 002b:00007f789ebf6038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f78a0bc5fa0 RCX: 00007f78a098ebe9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f78a0bc5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f78a0bc6038 R14: 00007f78a0bc5fa0 R15: 00007ffed1d60138
 </TASK>

Showing all locks held in the system:
8 locks held by kworker/0:0/9:
1 lock held by khungtaskd/34:
 #0: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5672:
 #0: ffff88810f7860a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029062f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
3 locks held by kworker/u10:31/7313:
 #0: ffff88801b3ed948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000343fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff8880271260e0 (&type->s_umount_key#65){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0
2 locks held by syz.5.3219/20275:
 #0: ffff888026b1b4f8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x247/0x320
 #1: ffff888027126428 (sb_writers#19){.+.+}-{0:0}, at: vfs_write+0x211/0xb30
2 locks held by syz.4.3424/20996:
 #0: ffff8880271260e0 (&type->s_umount_key#65){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
 #1: ffff88801bb087d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10
2 locks held by syz.1.3478/21151:
 #0: ffff8880271260e0 (&type->s_umount_key#65){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
 #1: ffff88801bb087d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10
2 locks held by syz.8.3632/22055:
 #0: ffff8880271260e0 (&type->s_umount_key#65){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
 #1: ffff88801bb087d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10
2 locks held by syz.5.3897/23387:

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 34 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
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+0x189/0x250
 nmi_cpu_backtrace+0x39e/0x3d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 watchdog+0xf93/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 23387 Comm: syz.5.3897 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:rcu_qs+0x0/0x170
Code: f7 dd 0f 80 dc fe ff ff e9 ab fe ff ff 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 55 48 89 e5 41 57 41 56 53 48 83 e4 e0 48 83 ec 60 65
RSP: 0018:ffffc90002bdef58 EFLAGS: 00000046
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 00000000ffffffff
RBP: ffffc90002bdf0d0 R08: ffffffff8e13f243 R09: 1ffffffff1c27e48
R10: dffffc0000000000 R11: fffffbfff1c27e49 R12: ffff88804b03afa8
R13: ffff88801f393980 R14: ffff88804b03af91 R15: 0000000000000001
FS:  00007f8eae88e6c0(0000) GS:ffff8880b861b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8ea4103000 CR3: 00000000307ae000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 rcu_note_context_switch+0xc5e/0x1140
 __schedule+0x35d/0x4cc0
 preempt_schedule_irq+0xb5/0x150
 irqentry_exit+0x6f/0x90
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:lock_acquire+0x175/0x360
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 3b f4 02 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc90002bdf470 EFLAGS: 00000206
RAX: beba6fb26265ef00 RBX: 0000000000000000 RCX: beba6fb26265ef00
RDX: 0000000000000000 RSI: ffffffff8dba6cb7 RDI: ffffffff8be33680
RBP: ffffffff81f6a15c R08: 0000000000000000 R09: ffffffff81f6a15c
R10: 0000000000000406 R11: 0000000000000002 R12: 0000000000000002
R13: ffffffff8e139f20 R14: 0000000000000000 R15: 0000000000000246
 folio_try_get+0x38/0x340
 find_lock_entries+0x24f/0xa60
 shmem_undo_range+0x254/0x14b0
 shmem_evict_inode+0x272/0xa70
 evict+0x504/0x9c0
 __dentry_kill+0x209/0x660
 dput+0x19f/0x2b0
 __fput+0x68e/0xa70
 fput_close_sync+0x119/0x200
 __x64_sys_close+0x7f/0x110
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8ead98d84a
Code: 48 3d 00 f0 ff ff 77 48 c3 0f 1f 80 00 00 00 00 48 83 ec 18 89 7c 24 0c e8 43 91 02 00 8b 7c 24 0c 89 c2 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 36 89 d7 89 44 24 0c e8 a3 91 02 00 8b 44 24
RSP: 002b:00007f8eae88de00 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 0000000000000008 RCX: 00007f8ead98d84a
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000007
RBP: 0000000000000010 R08: 0000000000000000 R09: 0000000000005aca
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000007
R13: 00007f8eae88def0 R14: 00007f8eae88e668 R15: 00007f8ea3600000
 </TASK>
