INFO: task syz.4.35726:10309 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.4.35726     state:D stack:28120 pid:10309 tgid:10308 ppid:9574   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x1821/0x5740
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7f7/0x1550
 nbd_ioctl+0xac9/0xe40
 blkdev_ioctl+0x5e3/0x740
 __se_sys_ioctl+0xfc/0x170
 do_syscall_64+0x174/0x580
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fab6f59ce59
RSP: 002b:00007fab704a5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fab6f815fa0 RCX: 00007fab6f59ce59
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003
RBP: 00007fab6f632d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fab6f816038 R14: 00007fab6f815fa0 R15: 00007fff6a6ef148
 </TASK>
INFO: task syz.4.35726:10311 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.4.35726     state:D stack:25632 pid:10311 tgid:10308 ppid:9574   task_flags:0x480140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x1821/0x5740
 schedule+0x164/0x360
 blk_mq_freeze_queue_wait+0x101/0x180
 queue_limits_commit_update_frozen+0x55/0xd0
 nbd_set_size+0x454/0x680
 nbd_ioctl+0x630/0xe40
 blkdev_ioctl+0x5e3/0x740
 __se_sys_ioctl+0xfc/0x170
 do_syscall_64+0x174/0x580
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fab6f59ce59
RSP: 002b:00007fab70463028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fab6f816180 RCX: 00007fab6f59ce59
RDX: 0000000000000080 RSI: 000000000000ab02 RDI: 0000000000000003
RBP: 00007fab6f632d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fab6f816218 R14: 00007fab6f816180 R15: 00007fff6a6ef148
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/36:
 #0: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by klogd/5056:
 #0: ffff88823c63aee0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x31/0x150
 #1: ffff88823c624588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880
2 locks held by getty/5446:
 #0: ffff88817860c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900034732e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0
1 lock held by udevd/5479:
 #0: ffff888104711350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
1 lock held by syz.4.35726/10309:
 #0: ffff888104344a60 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_ioctl+0xac9/0xe40
4 locks held by syz.4.35726/10311:
 #0: ffff888104344a60 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_ioctl+0x133/0xe40
 #1: ffff888103f3a288 (&q->limits_lock){+.+.}-{4:4}, at: nbd_set_size+0x263/0x680
 #2: ffff888103f39c50 (&q->q_usage_counter(io)#53){++++}-{0:0}, at: queue_limits_commit_update_frozen+0x55/0xd0
 #3: ffff888103f39c88 (&q->q_usage_counter(queue)#37){+.+.}-{0:0}, at: queue_limits_commit_update_frozen+0x55/0xd0
1 lock held by syz.9.36673/13737:
 #0: ffff888104711350 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27e/0x470
1 lock held by syz.9.36673/13738:
 #0: ffff888104711350 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27e/0x470
1 lock held by syz.9.36673/13741:
 #0: ffff888104711350 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27e/0x470
1 lock held by syz.9.36673/13744:
 #0: ffff888104711350 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27e/0x470

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

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/0x300
 sys_info+0x135/0x170
 watchdog+0xfd3/0x1030
 kthread+0x389/0x470
 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: 14410 Comm: syz.1.36833 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:memset_orig+0x60/0xb0
Code: 48 89 47 08 48 89 47 10 48 89 47 18 48 89 47 20 48 89 47 28 48 89 47 30 48 89 47 38 48 8d 7f 40 75 d8 0f 1f 84 00 00 00 00 00 <89> d1 83 e1 38 74 14 c1 e9 03 66 0f 1f 44 00 00 ff c9 48 89 07 48
RSP: 0018:ffffc900095bf4d0 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffc900095bf5f8 RCX: 0000000000000000
RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffffc900095bf5f8
RBP: dffffc0000000000 R08: ffffc900095bf607 R09: 0000000000000000
R10: ffffc900095bf5f8 R11: fffff520012b7ec1 R12: ffffc900095bf950
R13: 1ffff920012b7eb7 R14: ffffc900095bf5a8 R15: ffffc900095bf5f0
FS:  000055556058b500(0000) GS:ffff8882a929f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f17d7fea2f8 CR3: 00000001770ac000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 unwind_next_frame+0xf33/0x2550
 arch_stack_walk+0x11b/0x150
 stack_trace_save+0xa9/0x100
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_cache_noprof+0x31c/0x660
 kmem_cache_free+0x156/0x650
 tear_down_vmas+0x312/0x520
 exit_mmap+0x4b6/0x9e0
 __mmput+0x118/0x430
 exit_mm+0x1f6/0x2d0
 do_exit+0x6a2/0x22c0
 do_group_exit+0x21b/0x2d0
 __x64_sys_exit_group+0x3f/0x40
 x64_sys_call+0x221a/0x2240
 do_syscall_64+0x174/0x580
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8228d9ce59
Code: Unable to access opcode bytes at 0x7f8228d9ce2f.
RSP: 002b:00007ffc881a2eb8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f8228d9ce59
RDX: 00007f8227ff9000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffc881a2f1c R08: 0000000000000000 R09: 00000000000927c0
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000009b1
R13: 00000000000927c0 R14: 0000000000328ea6 R15: 00007ffc881a2f70
 </TASK>
