INFO: task syz.1.3318:18785 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.1.3318      state:D stack:24552 pid:18785 tgid:18784 ppid:18157  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17d9/0x56c0
 schedule+0x164/0x2b0
 cgroup_lock_and_drain_offline+0x51a/0x650
 cgroup_kn_lock_live+0x120/0x230
 cgroup_subtree_control_write+0x4b5/0x1080
 cgroup_file_write+0x331/0x8f0
 kernfs_fop_write_iter+0x3a4/0x540
 vfs_write+0x612/0xba0
 ksys_write+0x150/0x270
 do_syscall_64+0x174/0x580
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f600e99e0d9
RSP: 002b:00007f600f8ca028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f600ec25fa0 RCX: 00007f600e99e0d9
RDX: 000000000000000b RSI: 0000200000000180 RDI: 0000000000000008
RBP: 00007f600ea35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f600ec26038 R14: 00007f600ec25fa0 R15: 00007ffe9a9f9b18
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
3 locks held by kworker/u11:1/4990:
 #0: ffff88803884c140 ((wq_completion)hci8){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #1: ffffc9000ab8fc40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #2: ffff88802e1f8ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1cb/0x3f0
5 locks held by kworker/1:12/13729:
 #0: ffff88823c410f40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #1: ffffc900073efc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #2: ffff88816cc3d1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4d30
 #3: ffff8881752af1d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450
 #4: ffff8881b167c1a0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450
3 locks held by syz.1.3318/18785:
 #0: ffff888112ff64f0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320
 #1: ffff8881109d0450 (sb_writers#9){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0
 #2: ffff88816e298080 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d8/0x540

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 34 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 18858 Comm: kworker/u10:44 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
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:lock_release+0xd6/0x3c0
Code: 01 00 00 00 83 3d 79 92 b4 0e 00 0f 84 90 01 00 00 41 8b 87 98 0b 00 00 85 c0 0f 84 17 01 00 00 4c 89 6c 24 18 48 89 5c 24 08 <44> 8d 60 ff 49 8d af a0 0b 00 00 4d 63 ec 48 89 04 24 83 f8 32 0f
RSP: 0018:ffffc90006447478 EFLAGS: 00000006
RAX: 0000000000000005 RBX: 0000000000000206 RCX: 0000000080000001
RDX: ffffc90006447501 RSI: ffffffff8e242ff1 RDI: ffffffff8c4bbe80
RBP: 1ffffffff21f7501 R08: ffffc90006447978 R09: 0000000000000000
R10: ffffc900064475d8 R11: fffff52000c88ebd R12: ffffc90006440000
R13: ffffffff8177827f R14: ffffffff8eb59c60 R15: ffff88816b661dc0
FS:  0000000000000000(0000) GS:ffff88818d955000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f64c3feb7c0 CR3: 000000010ed76000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 unwind_next_frame+0x1baa/0x2550
 arch_stack_walk+0x11b/0x150
 stack_trace_save+0xa9/0x100
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x40/0x50
 __kasan_slab_free+0x5c/0x80
 kfree+0x1c5/0x640
 skb_release_data+0x85e/0xab0
 __kfree_skb+0x5d/0x210
 nsim_dev_trap_report_work+0x7ac/0xb40
 process_scheduled_works+0xa8e/0x14e0
 worker_thread+0xa47/0xfb0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
