INFO: task syz.1.668:9140 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.668       state:D stack:25128 pid:9140  tgid:9138  ppid:5844   task_flags:0x400040 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x5fd/0x8f0
 down_read+0x98/0x2e0
 super_lock+0x2a9/0x3b0
 __iterate_supers+0x126/0x290
 ksys_sync+0x94/0x150
 __ia32_sys_sync+0xe/0x20
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f796bd8ebe9
RSP: 002b:00007f796ccde038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f796bfc5fa0 RCX: 00007f796bd8ebe9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f796bfc5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f796bfc6038 R14: 00007f796bfc5fa0 R15: 00007ffca233ab68
 </TASK>

Showing all locks held in the system:
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/5675:
 #0: ffff88802137e0a0 (&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
2 locks held by syz.7.423/8038:
1 lock held by syz.1.668/9140:
 #0: ffff8881234d80e0 (&type->s_umount_key#52){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.2.1081/13161:
 #0: ffff8881234d80e0 (&type->s_umount_key#52){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.5.1253/15067:
2 locks held by syz.5.1253/15074:
2 locks held by syz.0.1255/15073:
2 locks held by rm/15085:

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

NMI backtrace for cpu 0
CPU: 0 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 15073 Comm: syz.0.1255 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:native_apic_msr_write+0x39/0x50
Code: 74 2a 83 ff 30 74 25 eb 10 81 ff d0 00 00 00 74 1b 81 ff e0 00 00 00 74 13 c1 ef 04 81 c7 00 08 00 00 89 f9 89 f0 31 d2 0f 30 <66> 90 c3 cc cc cc cc cc f3 0f 1e fa 89 f6 31 d2 e9 92 a4 8e 03 66
RSP: 0018:ffffc900001e0e50 EFLAGS: 00000046
RAX: 000000000000bd66 RBX: ffff888136623900 RCX: 0000000000000838
RDX: 0000000000000000 RSI: 000000000000bd66 RDI: 0000000000000838
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff81ae04ae
R10: 0000000000000003 R11: ffffffff81703490 R12: 00000000100024e8
R13: dffffc0000000000 R14: 000000000000bd66 R15: 0000000000000020
FS:  00007fded09f66c0(0000) GS:ffff8881a3c18000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a5441ee950 CR3: 0000000135082000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 lapic_next_event+0x11/0x20
 clockevents_program_event+0x1cf/0x360
 hrtimer_interrupt+0x620/0xaa0
 __sysvec_apic_timer_interrupt+0x10b/0x410
 sysvec_apic_timer_interrupt+0xa1/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:_raw_spin_unlock_irq+0x29/0x50
Code: 90 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 7a 0f 21 f6 48 89 df e8 d2 a6 21 f6 e8 2d f9 4a f6 fb bf 01 00 00 00 <e8> b2 9e 13 f6 65 8b 05 6b 21 24 07 85 c0 74 07 5b e9 51 4c 00 00
RSP: 0018:ffffc90009ba7730 EFLAGS: 00000286
RAX: 4239e6f61a65c700 RBX: ffff888035c32ad8 RCX: 4239e6f61a65c700
RDX: 0000000000000006 RSI: ffffffff8d9b8241 RDI: 0000000000000001
RBP: ffffc90009ba7870 R08: ffffffff8fa39037 R09: 1ffffffff1f47206
R10: dffffc0000000000 R11: fffffbfff1f47207 R12: ffffc90009ba77c0
R13: 00000003fffffffc R14: 0000000000000000 R15: ffff888112524000
 shmem_add_to_page_cache+0x8ee/0xba0
 shmem_alloc_and_add_folio+0x846/0xf60
 shmem_get_folio_gfp+0x59d/0x1660
 shmem_write_begin+0xf7/0x2b0
 generic_perform_write+0x2c5/0x900
 shmem_file_write_iter+0xf8/0x120
 vfs_write+0x5c9/0xb30
 ksys_write+0x145/0x250
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fded278d69f
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48
RSP: 002b:00007fded09f5df0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007fded278d69f
RDX: 0000000001000000 RSI: 00007fdec8400000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000009687
R10: 000020000001c302 R11: 0000000000000293 R12: 0000000000000003
R13: 00007fded09f5ef0 R14: 00007fded09f5eb0 R15: 00007fdec8400000
 </TASK>
