INFO: task syz.1.411:5634 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.411       state:D stack:25600 pid: 5634 ppid:  4185 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11c3/0x4350 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
 __mutex_lock_common+0xdf5/0x2400 kernel/locking/mutex.c:669
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 snd_seq_midisynth_remove+0x68/0x4e0 sound/core/seq/seq_midi.c:432
 __device_release_driver drivers/base/dd.c:1249 [inline]
 device_release_driver_internal+0x487/0x710 drivers/base/dd.c:1282
 bus_remove_device+0x2dd/0x400 drivers/base/bus.c:531
 device_del+0x63f/0xa80 drivers/base/core.c:3615
 snd_seq_device_dev_disconnect+0x39/0x40 sound/core/seq_device.c:182
 __snd_device_disconnect sound/core/device.c:63 [inline]
 snd_device_disconnect_all+0xcf/0x200 sound/core/device.c:215
 snd_card_disconnect+0x385/0x7d0 sound/core/init.c:528
 snd_card_free_when_closed+0x13/0x50 sound/core/init.c:617
 f_midi_unbind+0x99/0xf0 drivers/usb/gadget/function/f_midi.c:1291
 purge_configs_funcs+0x241/0x3a0 drivers/usb/gadget/configfs.c:1282
 configfs_composite_unbind+0xa0/0x1c0 drivers/usb/gadget/configfs.c:1461
 usb_gadget_remove_driver+0x15c/0x350 drivers/usb/gadget/udc/core.c:1495
 usb_gadget_unregister_driver+0x15d/0x4c0 drivers/usb/gadget/udc/core.c:1654
 unregister_gadget drivers/usb/gadget/configfs.c:252 [inline]
 gadget_dev_desc_UDC_store+0x174/0x2e0 drivers/usb/gadget/configfs.c:279
 flush_write_buffer fs/configfs/file.c:207 [inline]
 configfs_write_iter+0x30b/0x400 fs/configfs/file.c:229
 call_write_iter include/linux/fs.h:2173 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0x748/0xd70 fs/read_write.c:594
 ksys_write+0x153/0x260 fs/read_write.c:647
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f0b25019019
RSP: 002b:00007f0b23250028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f0b252a1090 RCX: 00007f0b25019019
RDX: 0000000000000001 RSI: 0000200000000b00 RDI: 0000000000000006
RBP: 00007f0b250b000c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0b252a1128 R14: 00007f0b252a1090 R15: 00007ffc2f88a838
 </TASK>
INFO: task syz.3.421:5663 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.421       state:D stack:27888 pid: 5663 ppid:  4191 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11c3/0x4350 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
 __mutex_lock_common+0xdf5/0x2400 kernel/locking/mutex.c:669
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
 raw_ioctl_run drivers/usb/gadget/legacy/raw_gadget.c:549 [inline]
 raw_ioctl+0x115e/0x3750 drivers/usb/gadget/legacy/raw_gadget.c:1256
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f9763d5ccab
RSP: 002b:00007f9761fb2f00 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f9763d5ccab
RDX: 0000000000000000 RSI: 0000000000005501 RDI: 0000000000000003
RBP: 00007f9761fb3fd0 R08: 0000000000000001 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000200000000200 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
INFO: task syz.4.425:5671 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.425       state:D stack:28976 pid: 5671 ppid:  4196 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11c3/0x4350 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
 __mutex_lock_common+0xdf5/0x2400 kernel/locking/mutex.c:669
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 function_make+0x1ee/0x350 drivers/usb/gadget/configfs.c:629
 configfs_mkdir+0x511/0x9e0 fs/configfs/dir.c:1360
 vfs_mkdir+0x386/0x570 fs/namei.c:4073
 do_mkdirat+0x1dd/0x5c0 fs/namei.c:4098
 __do_sys_mkdirat fs/namei.c:4113 [inline]
 __se_sys_mkdirat fs/namei.c:4111 [inline]
 __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4111
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f04a3c85019
RSP: 002b:00007f04a1edd028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f04a3f0cfa0 RCX: 00007f04a3c85019
RDX: 00000000000001ff RSI: 0000200000000400 RDI: ffffffffffffff9c
RBP: 00007f04a3d1c00c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f04a3f0d038 R14: 00007f04a3f0cfa0 R15: 00007ffc175b4a98
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/0:1/13:
 #0: ffff88814c270138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc90000d27d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
 #2: ffffffff8d44d488 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x1530 net/ipv6/addrconf.c:4120
1 lock held by khungtaskd/27:
 #0: ffffffff8c31ef60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
3 locks held by kworker/1:2/1107:
 #0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc90005037d00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
 #2: ffff888057e26240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x283/0x3380 drivers/net/netdevsim/fib.c:1480
2 locks held by getty/3939:
 #0: ffff88802cf8e098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc900025e62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x594/0x1a50 drivers/tty/n_tty.c:2158
8 locks held by kworker/0:5/4230:
 #0: ffff88801bec7d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc9000315fd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
 #2: ffff888147e82220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
 #2: ffff888147e82220 (&dev->mutex){....}-{3:3}, at: hub_event+0x178/0x5260 drivers/usb/core/hub.c:5827
 #3: ffff8880741c1220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
 #3: ffff8880741c1220 (&dev->mutex){....}-{3:3}, at: usb_disconnect+0xf8/0x8a0 drivers/usb/core/hub.c:2278
 #4: ffff8880741c21a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
 #4: ffff8880741c21a8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1064 [inline]
 #4: ffff8880741c21a8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa1/0x710 drivers/base/dd.c:1279
 #5: ffffffff8d3f5e88 (register_mutex#7){+.+.}-{3:3}, at: usb_audio_disconnect+0xd0/0x6f0 sound/usb/card.c:960
 #6: ffff888078b93200 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
 #6: ffff888078b93200 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1064 [inline]
 #6: ffff888078b93200 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa1/0x710 drivers/base/dd.c:1279
 #7: ffffffff8d3bd028 (register_mutex#6){+.+.}-{3:3}, at: snd_seq_midisynth_remove+0x68/0x4e0 sound/core/seq/seq_midi.c:432
4 locks held by kworker/u4:8/4370:
2 locks held by kworker/1:8/4509:
 #0: ffff888016c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc9000338fd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
8 locks held by syz.1.411/5634:
 #0: ffff888077284d70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056
 #1: ffff88801df24460 (sb_writers#13){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590
 #2: ffff88802b3e3a88 (&buffer->mutex#2){+.+.}-{3:3}, at: configfs_write_iter+0x7d/0x400 fs/configfs/file.c:226
 #3: ffff88801b58e078 (&p->frag_sem){.+.+}-{3:3}, at: flush_write_buffer fs/configfs/file.c:205 [inline]
 #3: ffff88801b58e078 (&p->frag_sem){.+.+}-{3:3}, at: configfs_write_iter+0x20e/0x400 fs/configfs/file.c:229
 #4: ffff88807d3a7310 (&gi->lock){+.+.}-{3:3}, at: gadget_dev_desc_UDC_store+0xed/0x2e0 drivers/usb/gadget/configfs.c:276
 #5: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_unregister_driver+0x56/0x4c0 drivers/usb/gadget/udc/core.c:1651
 #6: ffff888024cf3200 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
 #6: ffff888024cf3200 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1064 [inline]
 #6: ffff888024cf3200 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa1/0x710 drivers/base/dd.c:1279
 #7: ffffffff8d3bd028 (register_mutex#6){+.+.}-{3:3}, at: snd_seq_midisynth_remove+0x68/0x4e0 sound/core/seq/seq_midi.c:432
1 lock held by syz.3.421/5663:
 #0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
4 locks held by syz.4.425/5671:
 #0: ffff88801df24460 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:386
 #1: ffff888061aa9aa0 (&default_group_class[depth - 1]#2/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:822 [inline]
 #1: ffff888061aa9aa0 (&default_group_class[depth - 1]#2/1){+.+.}-{3:3}, at: filename_create+0x20b/0x450 fs/namei.c:3843
 #2: ffffffff8ceceff0 (gadget_subsys.su_mutex){+.+.}-{3:3}, at: configfs_mkdir+0x4b5/0x9e0 fs/configfs/dir.c:1358
 #3: ffff88807d3a7310 (&gi->lock){+.+.}-{3:3}, at: function_make+0x1ee/0x350 drivers/usb/gadget/configfs.c:629
1 lock held by syz.5.431/5759:
 #0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
1 lock held by syz.6.427/5838:
 #0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
1 lock held by syz.7.436/5927:
 #0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
1 lock held by syz.9.440/5948:
 #0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
1 lock held by syz.8.446/5972:
 #0: ffff888061aa9aa0 (&default_group_class[depth - 1]#2){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:797 [inline]
 #0: ffff888061aa9aa0 (&default_group_class[depth - 1]#2){++++}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1687
1 lock held by syz.2.461/6106:
 #0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
1 lock held by syz.1.452/6169:
 #0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
1 lock held by syz.0.497/6641:
 #0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
1 lock held by syz.6.544/6846:
 #0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
1 lock held by syz.3.547/6850:
 #0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
1 lock held by syz.5.560/6888:
 #0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
1 lock held by syz.4.570/6926:
 #0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
1 lock held by syz.7.571/6929:
 #0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
3 locks held by syz.8.573/6988:
 #0: ffff888077279270 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056
 #1: ffff8881473e2460 (sb_writers#21){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590
 #2: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
1 lock held by syz.8.573/6990:
 #0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
1 lock held by syz.2.574/7032:
 #0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
5 locks held by syz.9.592/7067:
 #0: ffff88807899f9f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056
 #1: ffff88801df24460 (sb_writers#13){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590
 #2: ffff88803c557088 (&buffer->mutex#2){+.+.}-{3:3}, at: configfs_write_iter+0x7d/0x400 fs/configfs/file.c:226
 #3: ffff88801b58e078 (&p->frag_sem){.+.+}-{3:3}, at: flush_write_buffer fs/configfs/file.c:205 [inline]
 #3: ffff88801b58e078 (&p->frag_sem){.+.+}-{3:3}, at: configfs_write_iter+0x20e/0x400 fs/configfs/file.c:229
 #4: ffff88807d3a7310 (&gi->lock){+.+.}-{3:3}, at: gadget_dev_desc_UDC_store+0xed/0x2e0 drivers/usb/gadget/configfs.c:276
1 lock held by syz.0.601/7097:
 #0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
2 locks held by syz.1.606/7113:
 #0: ffff88801df24460 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:386
 #1: ffff888061aa9aa0 (&default_group_class[depth - 1]#2/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:822 [inline]
 #1: ffff888061aa9aa0 (&default_group_class[depth - 1]#2/1){+.+.}-{3:3}, at: filename_create+0x20b/0x450 fs/namei.c:3843
2 locks held by syz.1.606/7114:
 #0: ffff88801df24460 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:386
 #1: ffff888061aa9aa0 (&default_group_class[depth - 1]#2){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:797 [inline]
 #1: ffff888061aa9aa0 (&default_group_class[depth - 1]#2){++++}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1687
1 lock held by syz.6.615/7155:
 #0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
1 lock held by syz.3.634/7242:
 #0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
1 lock held by syz.7.632/7306:
 #0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
1 lock held by syz.4.656/7348:
 #0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
1 lock held by syz.5.658/7352:
 #0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
1 lock held by syz-executor/7359:
 #0: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline]
 #0: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a5/0x750 kernel/rcu/tree_exp.h:845
1 lock held by syz.8.670/7397:
 #0: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
 #0: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
 watchdog+0xe1b/0xe60 kernel/hung_task.c:369
 kthread+0x42e/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 1 skipped: idling at default_idle+0xb/0x10 arch/x86/kernel/process.c:729