INFO: task syz.4.6655:24092 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.4.6655      state:D stack:28808 pid:24092 tgid:24091 ppid:22024  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17d9/0x56c0
 schedule+0x164/0x2b0
 cgroup_lock_and_drain_offline+0x51a/0x650
 cgroup1_get_tree+0x9d/0x890
 vfs_get_tree+0x92/0x2a0
 do_new_mount+0x319/0xdc0
 __se_sys_mount+0x31d/0x420
 do_syscall_64+0x174/0x580
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f56dcd9e0d9
RSP: 002b:00007f56ddc91028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f56dd025fa0 RCX: 00007f56dcd9e0d9
RDX: 0000200000000240 RSI: 0000200000000000 RDI: 0000000000000000
RBP: 00007f56dce35024 R08: 0000200000000100 R09: 0000000000000000
R10: 0000000000010012 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f56dd026038 R14: 00007f56dd025fa0 R15: 00007fff81f84988
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/36:
 #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
5 locks held by kworker/1:3/985:
 #0: ffff888167c74d40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #1: ffffc90006cb7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #2: ffff888106f3f1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4d30
 #3: ffff888106f4c568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x20a1/0x4d30
 #4: ffff888106f5d160 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x20c9/0x4d30
2 locks held by getty/5423:
 #0: ffff88810edbb0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900033382e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360
3 locks held by kworker/1:4/5661:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #1: ffffc900047b7c40 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #2: ffffffff8ea0e940 (sched_map-wait-type-override){+.+.}-{3:3}, at: raw_spin_rq_lock_nested+0x2d/0x160
3 locks held by syz.3.931/8119:
4 locks held by kworker/1:8/11985:
3 locks held by syz.8.6864/24849:
 #0: ffff8881098324f0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320
 #1: ffff888114220450 (sb_writers#9){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0
 #2: ffff88811cf33880 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d8/0x540
1 lock held by syz-executor/25418:
 #0: ffff88810fafcea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x22a/0x5b0
1 lock held by syz-executor/26146:
 #0: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 36 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/0x380
 sys_info+0x135/0x170
 watchdog+0xfd7/0x1030
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 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: 26144 Comm: syz.3.7077 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:debug_check_no_obj_freed+0xf7/0x450
Code: 44 24 08 4c 89 f1 48 c1 e9 03 48 b8 00 00 00 00 00 fc ff df 48 89 4c 24 30 80 3c 01 00 74 08 4c 89 f7 e8 6c 6d 55 fd 4d 8b 3e <4d> 85 ff 0f 84 8c 02 00 00 4c 89 74 24 28 44 89 64 24 04 4c 89 6c
RSP: 0018:ffffc900048ef7b8 EFLAGS: 00000046
RAX: dffffc0000000000 RBX: 0000000000000001 RCX: 1ffffffff354f5e7
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc900048ef720
RBP: 0000000000000001 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200091dee4 R12: 0000000000000000
R13: ffff888037a03000 R14: ffffffff9aa7af38 R15: 0000000000000000
FS:  0000555564003500(0000) GS:ffff8882a8f56000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f812bc2c000 CR3: 000000016c1ea000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 free_pages_prepare+0x488/0xaf0
 __free_contig_range_common+0x174/0x340
 free_pages_bulk+0x48/0x120
 vfree+0x22f/0x490
 kcov_close+0x28/0x50
 __fput+0x418/0xa50
 task_work_run+0x1d9/0x270
 do_exit+0x73a/0x2360
 do_group_exit+0x22d/0x2f0
 get_signal+0x121b/0x12c0
 arch_do_signal_or_restart+0xbb/0x860
 exit_to_user_mode_loop+0x104/0x730
 do_syscall_64+0x353/0x580
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe7c0b9e0d9
Code: Unable to access opcode bytes at 0x7fe7c0b9e0af.
RSP: 002b:00007ffc0250f058 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffdfc RBX: 00000000000fa55c RCX: 00007fe7c0b9e0d9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fe7c0e25fac
RBP: 0000000000000bea R08: 3fffffffffffffff R09: 0000000000000000
R10: 00007ffc0250f160 R11: 0000000000000246 R12: 00007ffc0250f180
R13: 00007fe7c0e25fac R14: 00000000000fb146 R15: 00007ffc0250f160
 </TASK>
