INFO: task syz-executor830:5089 blocked for more than 143 seconds.
      Not tainted 6.3.0-rc4-next-20230331-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor830 state:D stack:27440 pid:5089  ppid:5086   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5333 [inline]
 __schedule+0x1d23/0x5650 kernel/sched/core.c:6658
 schedule+0xde/0x1a0 kernel/sched/core.c:6734
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6793
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0xa3b/0x1350 kernel/locking/mutex.c:747
 nbd_start_device_ioctl drivers/block/nbd.c:1421 [inline]
 __nbd_ioctl drivers/block/nbd.c:1482 [inline]
 nbd_ioctl+0x315/0xcf0 drivers/block/nbd.c:1522
 blkdev_ioctl+0x372/0x800 block/ioctl.c:615
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __x64_sys_ioctl+0x197/0x210 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f8772e95f99
RSP: 002b:00007f8772e42308 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f8772f1b4c8 RCX: 00007f8772e95f99
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003
RBP: 00007f8772f1b4c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f8772f1b4cc
R13: 00007f8772ee82b4 R14: 64626e2f7665642f R15: 0000000000022000
 </TASK>
INFO: task syz-executor830:5091 blocked for more than 143 seconds.
      Not tainted 6.3.0-rc4-next-20230331-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor830 state:D stack:28592 pid:5091  ppid:5086   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5333 [inline]
 __schedule+0x1d23/0x5650 kernel/sched/core.c:6658
 schedule+0xde/0x1a0 kernel/sched/core.c:6734
 blk_mq_freeze_queue_wait+0x116/0x160 block/blk-mq.c:144
 nbd_add_socket+0x168/0x960 drivers/block/nbd.c:1122
 __nbd_ioctl drivers/block/nbd.c:1465 [inline]
 nbd_ioctl+0x820/0xcf0 drivers/block/nbd.c:1522
 blkdev_ioctl+0x372/0x800 block/ioctl.c:615
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __x64_sys_ioctl+0x197/0x210 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f8772e95f99
RSP: 002b:00007f8772e21308 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f8772f1b4d8 RCX: 00007f8772e95f99
RDX: 0000000000000005 RSI: 000000000000ab00 RDI: 0000000000000004
RBP: 00007f8772f1b4d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f8772f1b4dc
R13: 00007f8772ee82b4 R14: 64626e2f7665642f R15: 0000000000022000
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/13:
 #0: ffffffff8c796630 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x31/0xd80 kernel/rcu/tasks.h:519
1 lock held by rcu_tasks_trace/14:
 #0: ffffffff8c796330 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x31/0xd80 kernel/rcu/tasks.h:519
1 lock held by khungtaskd/28:
 #0: ffffffff8c797240 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x390 kernel/locking/lockdep.c:6545
2 locks held by getty/4764:
 #0: ffff8880282f4098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x26/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc900015a02f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xef4/0x13e0 drivers/tty/n_tty.c:2176
1 lock held by syz-executor830/5089:
 #0: ffff88801ee1f198 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_start_device_ioctl drivers/block/nbd.c:1421 [inline]
 #0: ffff88801ee1f198 (&nbd->config_lock){+.+.}-{3:3}, at: __nbd_ioctl drivers/block/nbd.c:1482 [inline]
 #0: ffff88801ee1f198 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x315/0xcf0 drivers/block/nbd.c:1522
1 lock held by syz-executor830/5091:
 #0: ffff88801ee1f198 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x156/0xcf0 drivers/block/nbd.c:1515
1 lock held by udevd/5090:
 #0: ffff888146ec44c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev.part.0+0x9b/0xb80 block/bdev.c:735

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

NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.3.0-rc4-next-20230331-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x29c/0x350 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x2a4/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
 watchdog+0xe16/0x1090 kernel/hung_task.c:379
 kthread+0x33e/0x440 kernel/kthread.c:379
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 10 Comm: kworker/u4:0 Not tainted 6.3.0-rc4-next-20230331-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x0/0x20 kernel/kcov.c:303
Code: d6 fe ff ff 66 0f 1f 44 00 00 f3 0f 1e fa 48 8b 0c 24 0f b7 d6 0f b7 f7 bf 03 00 00 00 e9 b8 fe ff ff 0f 1f 84 00 00 00 00 00 <f3> 0f 1e fa 48 8b 0c 24 89 f2 89 fe bf 05 00 00 00 e9 9a fe ff ff
RSP: 0018:ffffc900000f79f8 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffffc900000f7a60 RCX: 0000000000000000
RDX: ffff888016799d40 RSI: 0000000000000002 RDI: 0000000000000002
RBP: 0000000000000002 R08: 0000000000000000 R09: ffffffff8e78a2d7
R10: fffffbfff1cf145a R11: 0000000000000000 R12: ffffffff81d55299
R13: 000000000000000f R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005638834a6680 CR3: 000000000c571000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 insn_decode+0x26/0x3b0 arch/x86/lib/insn.c:742
 arch_jump_entry_size+0xa4/0x110 arch/x86/kernel/jump_label.c:24
 __jump_label_patch+0x80/0x340 arch/x86/kernel/jump_label.c:45
 arch_jump_label_transform_queue+0x67/0x100 arch/x86/kernel/jump_label.c:137
 __jump_label_update+0x12e/0x410 kernel/jump_label.c:475
 jump_label_update+0x32f/0x410 kernel/jump_label.c:829
 static_key_disable_cpuslocked+0x156/0x1b0 kernel/jump_label.c:235
 static_key_disable+0x1a/0x20 kernel/jump_label.c:243
 toggle_allocation_gate mm/kfence/core.c:808 [inline]
 toggle_allocation_gate+0x143/0x230 mm/kfence/core.c:795
 process_one_work+0x99a/0x15e0 kernel/workqueue.c:2405
 worker_thread+0x67d/0x10c0 kernel/workqueue.c:2552
 kthread+0x33e/0x440 kernel/kthread.c:379
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.528 msecs