INFO: task syz.0.4131:27487 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.0.4131      state:D stack:24704 pid:27487 tgid:27486 ppid:24326  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x15dd/0x52d0
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_write_slowpath+0x899/0x1040
 down_write+0x1bc/0x200
 super_lock+0x289/0x3d0
 user_get_super+0xc8/0x120
 __se_sys_quotactl+0x540/0x9e0
 do_syscall_64+0x14d/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f20dd59c799
RSP: 002b:00007f20de509028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f20dd815fa0 RCX: 00007f20dd59c799
RDX: 0000000000000000 RSI: 0000200000000180 RDI: ffffffff80000201
RBP: 00007f20dd632c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f20dd816038 R14: 00007f20dd815fa0 R15: 00007ffe963b0c38
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e75e5a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by kworker/1:2/783:
 #0: ffff88810006b148 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0
 #1: ffffc90004f57c40 ((work_completion)(&fw_work->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0
2 locks held by getty/5632:
 #0: ffff8881138230a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029702f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0
2 locks held by syz-executor/21270:
7 locks held by kworker/1:5/22087:
1 lock held by syz-executor/27336:
 #0: ffffffff8e764838 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770
1 lock held by syz.0.4131/27487:
 #0: ffff888172de00e0 (&type->s_umount_key#64){++++}-{4:4}, at: super_lock+0x289/0x3d0

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

NMI backtrace for cpu 0
CPU: 0 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/0x300
 sys_info+0x135/0x170
 watchdog+0xfd9/0x1030
 kthread+0x388/0x470
 ret_from_fork+0x51e/0xb90
 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: 22087 Comm: kworker/1:5 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: usb_hub_wq hub_event
RIP: 0010:deref_stack_reg+0x1bd/0x230
Code: 30 4c 89 c7 49 89 f7 e8 11 08 00 00 49 89 c6 48 8b 5c 24 18 48 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 53 24 b8 00 <4c> 89 33 b0 01 eb 02 31 c0 48 83 c4 20 5b 41 5c 41 5d 41 5e 41 5f
RSP: 0018:ffffc90000a08460 EFLAGS: 00000046
RAX: 1ffff920001410c5 RBX: ffffc90000a08628 RCX: 0000000000000001
RDX: ffffc90000a08628 RSI: dffffc0000000000 RDI: ffffc90000a08670
RBP: 1ffff920001410bd R08: ffffc90000a08670 R09: 0000000000000000
R10: ffffc90000a08638 R11: fffff520001410c9 R12: 1ffff920001410be
R13: 1ffff920001410bf R14: ffffc90000a08720 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8882a9465000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd38b5cd20 CR3: 00000001131be000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 unwind_next_frame+0x18c6/0x23c0
 __unwind_start+0x5b8/0x760
 arch_stack_walk+0xe3/0x150
 stack_trace_save+0xa9/0x100
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5c/0x80
 kmem_cache_free+0x189/0x630
 ath6kl_usb_recv_complete+0x1d6/0x4d0
 __usb_hcd_giveback_urb+0x376/0x540
 dummy_timer+0xbbd/0x45d0
 __hrtimer_run_queues+0x53a/0xcc0
 hrtimer_run_softirq+0x182/0x5a0
 handle_softirqs+0x22a/0x870
 __irq_exit_rcu+0x5f/0x150
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0xa6/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:unwind_next_frame+0x50/0x23c0
Code: 48 89 d8 48 c1 e8 03 48 89 44 24 30 80 3c 28 00 74 08 48 89 df e8 40 4b b8 00 48 89 5c 24 10 49 8b 5e 48 4d 8d 6e 38 4c 89 e8 <48> c1 e8 03 48 89 44 24 58 80 3c 28 00 74 08 4c 89 ef e8 19 4b b8
RSP: 0018:ffffc90007ade5b8 EFLAGS: 00000246
RAX: ffffc90007ade6c0 RBX: ffffffff86da8c37 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: ffffffff86da8c37 RDI: ffffc90007ade688
RBP: dffffc0000000000 R08: ffffc90007ade750 R09: 0000000000000005
R10: ffffc90007ade6d8 R11: ffffffff81b0b630 R12: ffff888168491d40
R13: ffffc90007ade6c0 R14: ffffc90007ade688 R15: ffffc90007ade688
 arch_stack_walk+0x11b/0x150
 stack_trace_save+0xa9/0x100
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_node_track_caller_noprof+0x4db/0x7b0
 __alloc_skb+0x2c1/0x7d0
 __netdev_alloc_skb+0xc1/0x810
 ath6kl_usb_post_recv_transfers+0x207/0x6f0
 ath6kl_usb_power_on+0x6a/0x280
 ath6kl_core_init+0x1e1/0x10b0
 ath6kl_usb_probe+0x14df/0x15d0
 usb_probe_interface+0x668/0xc90
 really_probe+0x267/0xaf0
 __driver_probe_device+0x18c/0x320
 driver_probe_device+0x4f/0x240
 __device_attach_driver+0x279/0x430
 bus_for_each_drv+0x258/0x2f0
 __device_attach+0x2c5/0x450
 device_initial_probe+0xa1/0xd0
 bus_probe_device+0x12a/0x220
 device_add+0x7b6/0xb70
 usb_set_configuration+0x1a87/0x2110
 usb_generic_driver_probe+0x8d/0x150
 usb_probe_device+0x1c4/0x3b0
 really_probe+0x267/0xaf0
 __driver_probe_device+0x18c/0x320
 driver_probe_device+0x4f/0x240
 __device_attach_driver+0x279/0x430
 bus_for_each_drv+0x258/0x2f0
 __device_attach+0x2c5/0x450
 device_initial_probe+0xa1/0xd0
 bus_probe_device+0x12a/0x220
 device_add+0x7b6/0xb70
 usb_new_device+0xa08/0x16f0
 hub_event+0x2a1c/0x4f30
 process_scheduled_works+0xb6e/0x18c0
 worker_thread+0xa53/0xfc0
 kthread+0x388/0x470
 ret_from_fork+0x51e/0xb90
 ret_from_fork_asm+0x1a/0x30
 </TASK>
