INFO: task syz.4.310:7716 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.310       state:D stack:28392 pid:7716  tgid:7715  ppid:6787   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: 0033:0x7f5efc18eba9
RSP: 002b:00007f5efd077038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f5efc3d5fa0 RCX: 00007f5efc18eba9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f5efc3d5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5efc3d6038 R14: 00007f5efc3d5fa0 R15: 00007ffeda108dc8
 </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/5673:
 #0: ffff88810fbca0a0 (&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-executor/5843:
4 locks held by udevd/5848:
 #0: ffff88804a4c1e80 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe10
 #1: ffff888043fd0888 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x55/0x3c0
 #2: ffff888028f88698 (kn->active#31){++++}-{0:0}, at: kernfs_seq_start+0x75/0x3c0
 #3: ffff88811f6ad198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0
6 locks held by kworker/1:4/5896:
 #0: ffff88801bb6a148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900038afbc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff8880238ab198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20
 #3: ffff88811f6ad198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400
 #4: ffff88811f3d8160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400
 #5: ffffffff8f48e468 (register_mutex#7){+.+.}-{4:4}, at: usb_audio_probe+0x390/0x1e10
3 locks held by kworker/1:5/5909:
2 locks held by kworker/u10:5/6995:
 #0: ffff888105e38148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90003147bc0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
1 lock held by syz.4.310/7716:
 #0: ffff8881096960e0 (&type->s_umount_key#60){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
5 locks held by dhcpcd-run-hook/9965:

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

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: 9964 Comm: dhcpcd-run-hook 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:mark_lock+0x3c/0x190
Code: 00 03 00 83 f9 01 bb 09 00 00 00 83 db 00 83 fa 08 0f 45 da bd 01 00 00 00 89 d9 d3 e5 25 ff 1f 00 00 48 0f a3 05 04 e6 0a 12 <73> 10 48 69 c0 c8 00 00 00 48 8d 88 10 73 49 93 eb 48 83 3d 6b 75
RSP: 0018:ffffc900001e0dc8 EFLAGS: 00000007
RAX: 0000000000000606 RBX: 0000000000000003 RCX: 0000000000000003
RDX: 0000000000000003 RSI: ffff888040430af0 RDI: ffff888040430000
RBP: 0000000000000008 R08: ffffffff8fa3a037 R09: 1ffffffff1f47406
R10: dffffc0000000000 R11: fffffbfff1f47407 R12: ffff888040430af0
R13: 0000000000000000 R14: ffff888040430af0 R15: 0000000000000000
FS:  00007f2c59d9b380(0000) GS:ffff8881a3c15000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055905b8ffb40 CR3: 000000003ce54000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 lockdep_hardirqs_on_prepare+0x129/0x2a0
 trace_hardirqs_on+0x28/0x40
 handle_softirqs+0x1a8/0x870
 __irq_exit_rcu+0xca/0x1f0
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0xa6/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:alloc_pages_mpol+0x3c8/0x4a0
Code: ff 89 ee e8 0a c1 9f ff 85 ed 74 50 e8 c1 bc 9f ff eb 23 e8 ba bc 9f ff 48 85 db 0f 85 c5 fe ff ff e8 ac bc 9f ff 31 db eb 0c <e8> a3 bc 9f ff eb 05 e8 9c bc 9f ff 65 48 8b 05 d4 bd 80 10 48 3b
RSP: 0018:ffffc9000332f2a0 EFLAGS: 00000293
RAX: 0000000000000002 RBX: ffffea000440f1c0 RCX: 0000000000000003
RDX: ffffffff821ff0d2 RSI: ffffffff8e24fb40 RDI: 0000000000000001
RBP: dffffc0000000000 R08: ffff888040430000 R09: 0000000000000002
R10: 0000000000000006 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000001 R14: 0000000000000001 R15: 0000000000440dc0
 alloc_pages_noprof+0xa9/0x190
 pte_alloc_one+0x21/0x170
 __pte_alloc+0x25/0x1a0
 copy_pmd_range+0x6a91/0x71d0
 copy_page_range+0xc14/0x1270
 dup_mmap+0xf57/0x1ac0
 copy_mm+0x13c/0x4b0
 copy_process+0x1706/0x3c00
 kernel_clone+0x21e/0x840
 __x64_sys_clone+0x18b/0x1e0
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2c59ed5a12
Code: 41 5d 41 5e 41 5f c3 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 10 48 8b 15 e7 43 0f 00 f7 d8 64 89 02 48 83
RSP: 002b:00007fff0a7fda28 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 000055905b8fa901 RCX: 00007f2c59ed5a12
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 000055905b8fbb70 R08: 0000000000000000 R09: 0000000000000007
R10: 00007f2c59d9b650 R11: 0000000000000246 R12: 000055905b8fe338
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
