INFO: task syz.1.1301:9279 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.1.1301      state:D stack:27432 pid:9279  tgid:9277  ppid:5596   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17d4/0x5630
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7c1/0x1550
 write_versions+0x95/0xe30
 nfsctl_transaction_write+0x10f/0x160
 vfs_write+0x296/0xba0
 ksys_write+0x150/0x270
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb54319e159
RSP: 002b:00007fb544070028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fb543426090 RCX: 00007fb54319e159
RDX: 0000000000000009 RSI: 0000200000000540 RDI: 0000000000000003
RBP: 00007fb54323506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb543426128 R14: 00007fb543426090 R15: 00007fffaae3eea8
 </TASK>
INFO: task syz.1.1301:9281 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.1.1301      state:D stack:27432 pid:9281  tgid:9277  ppid:5596   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17d4/0x5630
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7c1/0x1550
 write_threads+0x39d/0x5a0
 nfsctl_transaction_write+0x10f/0x160
 vfs_write+0x296/0xba0
 ksys_write+0x150/0x270
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb54319e159
RSP: 002b:00007fb54404f028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fb543426180 RCX: 00007fb54319e159
RDX: 0000000000000002 RSI: 0000200000000180 RDI: 0000000000000003
RBP: 00007fb54323506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb543426218 R14: 00007fb543426180 R15: 00007fffaae3eea8
 </TASK>
INFO: task syz.5.1302:9282 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.5.1302      state:D stack:27432 pid:9282  tgid:9280  ppid:8167   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17d4/0x5630
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7c1/0x1550
 write_versions+0x95/0xe30
 nfsctl_transaction_write+0x10f/0x160
 vfs_write+0x296/0xba0
 ksys_write+0x150/0x270
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5f0f99e159
RSP: 002b:00007f5f10887028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f5f0fc25fa0 RCX: 00007f5f0f99e159
RDX: 0000000000000006 RSI: 0000200000000180 RDI: 0000000000000003
RBP: 00007f5f0fa3506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5f0fc26038 R14: 00007f5f0fc25fa0 R15: 00007ffed6555308
 </TASK>
INFO: task syz.5.1302:9283 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.5.1302      state:D stack:27432 pid:9283  tgid:9280  ppid:8167   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17d4/0x5630
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7c1/0x1550
 write_threads+0x39d/0x5a0
 nfsctl_transaction_write+0x10f/0x160
 vfs_write+0x296/0xba0
 ksys_write+0x150/0x270
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5f0f99e159
RSP: 002b:00007f5f10866028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f5f0fc26090 RCX: 00007f5f0f99e159
RDX: 0000000000000002 RSI: 00002000000002c0 RDI: 0000000000000004
RBP: 00007f5f0fa3506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5f0fc26128 R14: 00007f5f0fc26090 R15: 00007ffed6555308
 </TASK>

Showing all locks held in the system:
locks held by kworker/1:1/31: 3, on CPU#1:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa1a/0x14c0
 #1: ffffc90000a67c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa1a/0x14c0
 #2: ffff888173b92250 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x1fd/0x3b0
locks held by khungtaskd/35: 1, last CPU#1:
 #0: ffffffff8eb5a0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
locks held by getty/5420: 2, on CPU#1:
 #0: ffff88816edf00a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900034762e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360
locks held by syz.1.1301/9278: 3, on CPU#0:
 #0: ffff88810d4cd4f0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320
 #1: ffff888118b36460 (sb_writers#39){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0
 #2: ffffffff8ee8fbe0 (nfsd_mutex){+.+.}-{4:4}, at: write_ports+0xb5/0xd10
locks held by syz.1.1301/9279: 3, on CPU#1:
 #0: ffff88816aada0f0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320
 #1: ffff888118b36460 (sb_writers#39){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0
 #2: ffffffff8ee8fbe0 (nfsd_mutex){+.+.}-{4:4}, at: write_versions+0x95/0xe30
locks held by syz.1.1301/9281: 3, on CPU#0:
 #0: ffff8881120be2f0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320
 #1: ffff888118b36460 (sb_writers#39){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0
 #2: ffffffff8ee8fbe0 (nfsd_mutex){+.+.}-{4:4}, at: write_threads+0x39d/0x5a0
locks held by syz.5.1302/9282: 3, on CPU#1:
 #0: ffff88816f8ccef0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320
 #1: ffff8881a7a24460 (sb_writers#39){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0
 #2: ffffffff8ee8fbe0 (nfsd_mutex){+.+.}-{4:4}, at: write_versions+0x95/0xe30
locks held by syz.5.1302/9283: 3, on CPU#0:
 #0: ffff88810f273af0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320
 #1: ffff8881a7a24460 (sb_writers#39){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0
 #2: ffffffff8ee8fbe0 (nfsd_mutex){+.+.}-{4:4}, at: write_threads+0x39d/0x5a0
locks held by syz.4.2666/12814: 2, on CPU#1:
 #0: ffff88819ac1e0e8 (&type->s_umount_key#126){++++}-{4:4}, at: deactivate_super+0xac/0xe0
 #1: ffffffff8ee8fbe0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x4e/0xd0
locks held by syz.8.2746/12988: 2, on CPU#1:
 #0: ffff8881102ec0e8 (&type->s_umount_key#126){++++}-{4:4}, at: deactivate_super+0xac/0xe0
 #1: ffffffff8ee8fbe0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x4e/0xd0
locks held by syz-executor/13017: 3, on CPU#0:
 #0: ffff88801fb40ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x22a/0x5b0
 #1: ffff88801fb400b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x61f/0x10a0
 #2: ffffffff8eb603e8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770
locks held by syz.6.2765/13071: 5, on CPU#0:
 #0: ffff88816c6b8ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x22a/0x5b0
 #1: ffff88816c6b80b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x61f/0x10a0
 #2: ffffffff901b7900 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0x99/0x260
 #3: ffff88811dfcf2f8 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x9f/0x520
 #4: ffffffff8eb603e8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 35 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+0x17d/0x390
 sys_info+0x135/0x170
 watchdog+0xfd7/0x1030
 kthread+0x38b/0x480
 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: 0 Comm: swapper/0 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:pv_native_safe_halt+0xf/0x20
Code: ac 7a 02 c3 cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 33 f1 13 00 fb f4 <e9> 4c 09 03 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffffff8e807ca0 EFLAGS: 00000206
RAX: 00000000003ac64b RBX: ffffffff819b2050 RCX: 8000000000000001
RDX: 0000000000000001 RSI: ffffffff8e2346c1 RDI: ffffffff8c4bdd80
RBP: ffffffff8e807d78 R08: ffff88812103389b R09: 1ffff11024206713
R10: dffffc0000000000 R11: ffffed1024206714 R12: 0000000000000000
R13: 1ffffffff1d11df0 R14: 1ffffffff1d00f9c R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff88818d939000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc84d7eb840 CR3: 000000000e946000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 default_idle+0x9/0x20
 default_idle_call+0x72/0xb0
 do_idle+0x2e0/0x540
 cpu_startup_entry+0x43/0x60
 rest_init+0x378/0x3a0
 start_kernel+0x392/0x3e0
 x86_64_start_reservations+0x24/0x30
 x86_64_start_kernel+0x137/0x1b0
 common_startup_64+0x13e/0x157
 </TASK>
