INFO: task syz-executor.0:6189 blocked for more than 143 seconds.
      Not tainted 6.16.0-rc2-next-20250620-syzkaller-04336-g5d4809e25903 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0  state:D stack:28648 pid:6189  tgid:6187  ppid:6159   task_flags:0x480140 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5313 [inline]
 __schedule+0x16f5/0x4d00 kernel/sched/core.c:6696
 __schedule_loop kernel/sched/core.c:6774 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6789
 blk_mq_freeze_queue_wait+0xf4/0x170 block/blk-mq.c:190
 blk_mq_freeze_queue include/linux/blk-mq.h:934 [inline]
 queue_limits_commit_update_frozen+0x5e/0x360 block/blk-settings.c:482
 nbd_set_size+0x494/0x6c0 drivers/block/nbd.c:374
 nbd_start_device_ioctl drivers/block/nbd.c:1527 [inline]
 __nbd_ioctl drivers/block/nbd.c:1602 [inline]
 nbd_ioctl+0x636/0xeb0 drivers/block/nbd.c:1642
 blkdev_ioctl+0x5a5/0x6d0 block/ioctl.c:704
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:907 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcf1ba79829
RSP: 002b:00007fcf1cb560c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fcf1bb8c030 RCX: 00007fcf1ba79829
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000004
RBP: 00007fcf1bad5074 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007fcf1bb8c030 R15: 00007fff4dc087b8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e13ef20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e13ef20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8e13ef20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
2 locks held by getty/5594:
 #0: ffff888034c4d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90002fee2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
4 locks held by syz-executor.0/6189:
 #0: ffff88802559aa30 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_ioctl+0x131/0xeb0 drivers/block/nbd.c:1635
 #1: ffff888142bedf08 (&q->limits_lock){+.+.}-{4:4}, at: queue_limits_start_update include/linux/blkdev.h:1002 [inline]
 #1: ffff888142bedf08 (&q->limits_lock){+.+.}-{4:4}, at: nbd_set_size+0x2a2/0x6c0 drivers/block/nbd.c:354
 #2: ffff888142bed8b0 (&q->q_usage_counter(io)#49){++++}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:934 [inline]
 #2: ffff888142bed8b0 (&q->q_usage_counter(io)#49){++++}-{0:0}, at: queue_limits_commit_update_frozen+0x5e/0x360 block/blk-settings.c:482
 #3: ffff888142bed8e8 (&q->q_usage_counter(queue)){+.+.}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:934 [inline]
 #3: ffff888142bed8e8 (&q->q_usage_counter(queue)){+.+.}-{0:0}, at: queue_limits_commit_update_frozen+0x5e/0x360 block/blk-settings.c:482

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc2-next-20250620-syzkaller-04336-g5d4809e25903 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
 watchdog+0xfee/0x1030 kernel/hung_task.c:470
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.16.0-rc2-next-20250620-syzkaller-04336-g5d4809e25903 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:sched_balance_rq+0x32bd/0x57a0 kernel/sched/fair.c:11713
Code: d9 15 00 00 8b 1b 83 fb 02 0f 82 5c 1b 00 00 48 8b 84 24 40 01 00 00 42 0f b6 04 28 84 c0 0f 85 d6 15 00 00 8b 05 e3 e9 0a 0e <39> d8 0f 42 d8 89 9c 24 0c 04 00 00 48 8b 44 24 30 4c 8d b0 70 0e
RSP: 0018:ffffc90000a08780 EFLAGS: 00000246
RAX: 0000000000000020 RBX: 0000000000000004 RCX: 1ffff110170c756d
RDX: ffff8880b8639f40 RSI: ffff8880b8639f40 RDI: ffff8880b8639f80
RBP: ffffc90000a08c38 R08: 00000000000008a3 R09: 0000000000000887
R10: 0000000000000887 R11: 00000000000003f3 R12: 0000000000000004
R13: dffffc0000000000 R14: 0000000000000001 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888125d26000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055e6affce660 CR3: 000000007566c000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 sched_balance_domains+0x49f/0x9e0 kernel/sched/fair.c:12144
 _nohz_idle_balance+0x59d/0x810 kernel/sched/fair.c:12579
 handle_softirqs+0x286/0x870 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 invoke_softirq kernel/softirq.c:453 [inline]
 __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
 instr_sysvec_call_function_single arch/x86/kernel/smp.c:266 [inline]
 sysvec_call_function_single+0xa3/0xc0 arch/x86/kernel/smp.c:266
 </IRQ>
 <TASK>
 asm_sysvec_call_function_single+0x1a/0x20 arch/x86/include/asm/idtentry.h:709
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: 43 dd 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d c3 d5 1a 00 f3 0f 1e fa fb f4 <e9> 18 dd 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197de0 EFLAGS: 000002c6
RAX: c0755d8f46828c00 RBX: ffffffff81975fd8 RCX: c0755d8f46828c00
RDX: 0000000000000001 RSI: ffffffff8d991d3a RDI: ffffffff8be320a0
RBP: ffffc90000197f20 R08: ffff8880b8732f1b R09: 1ffff110170e65e3
R10: dffffc0000000000 R11: ffffed10170e65e4 R12: ffffffff8fa193f0
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff110039d5b40
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:749
 default_idle_call+0x74/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:190 [inline]
 do_idle+0x1e8/0x510 kernel/sched/idle.c:330
 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428
 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315
 common_startup_64+0x13e/0x147
 </TASK>