INFO: task kworker/1:8:4236 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:8 state:D stack:24688 pid: 4236 ppid: 2 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: 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 usb_audio_disconnect+0x283/0x6f0 sound/usb/card.c:971 usb_unbind_interface+0x203/0x870 drivers/usb/core/driver.c:458 __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 usb_disable_device+0x3e7/0x8a0 drivers/usb/core/message.c:1472 usb_disconnect+0x33c/0x8a0 drivers/usb/core/hub.c:2292 hub_port_connect drivers/usb/core/hub.c:5346 [inline] hub_port_connect_change drivers/usb/core/hub.c:5642 [inline] port_event drivers/usb/core/hub.c:5804 [inline] hub_event+0x1d64/0x5260 drivers/usb/core/hub.c:5886 process_one_work+0x867/0xff0 kernel/workqueue.c:2310 worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457 kthread+0x42e/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 INFO: task syz.6.1656:11543 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.1656 state:D stack:26032 pid:11543 ppid: 5110 flags:0x00004004 Call Trace: 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 gadget_dev_desc_UDC_store+0xed/0x2e0 drivers/usb/gadget/configfs.c:276 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:2179 [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: 0033:0x7f3c02d6a159 RSP: 002b:00007f3c00f80028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f3c02ff2180 RCX: 00007f3c02d6a159 RDX: 000000000000000b RSI: 0000200000000680 RDI: 0000000000000006 RBP: 00007f3c02e01024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3c02ff2218 R14: 00007f3c02ff2180 R15: 00007fffb892a408 INFO: task syz.3.1693:11668 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.1693 state:D stack:24528 pid:11668 ppid: 4196 flags:0x00004004 Call Trace: 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 gadget_dev_desc_UDC_store+0xed/0x2e0 drivers/usb/gadget/configfs.c:276 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:2179 [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: 0033:0x7fddae0dc159 RSP: 002b:00007fddac2f2028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fddae364180 RCX: 00007fddae0dc159 RDX: 000000000000000b RSI: 0000200000000680 RDI: 0000000000000007 RBP: 00007fddae173024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fddae364218 R14: 00007fddae364180 R15: 00007fff58dc0d78 Showing all locks held in the system: 3 locks held by kworker/1:0/21: #0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc90000db7d00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 #2: ffff88803dde4240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x283/0x3380 drivers/net/netdevsim/fib.c:1480 1 lock held by khungtaskd/27: #0: ffffffff8c31ef60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/3948: #0: ffff88814d0bf098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900026562e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x594/0x1a50 drivers/tty/n_tty.c:2158 8 locks held by kworker/1:8/4236: #0: ffff88801be48138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc9000317fd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 #2: ffff88814834b220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline] #2: ffff88814834b220 (&dev->mutex){....}-{3:3}, at: hub_event+0x178/0x5260 drivers/usb/core/hub.c:5832 #3: ffff88807d395220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline] #3: ffff88807d395220 (&dev->mutex){....}-{3:3}, at: usb_disconnect+0xf8/0x8a0 drivers/usb/core/hub.c:2283 #4: ffff88807639b1a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline] #4: ffff88807639b1a8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1064 [inline] #4: ffff88807639b1a8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa1/0x710 drivers/base/dd.c:1279 #5: ffffffff8d3f5a08 (register_mutex#6){+.+.}-{3:3}, at: usb_audio_disconnect+0xd0/0x6f0 sound/usb/card.c:960 #6: ffff88802397e200 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline] #6: ffff88802397e200 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1064 [inline] #6: ffff88802397e200 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa1/0x710 drivers/base/dd.c:1279 #7: ffffffff8d3bcca8 (register_mutex#7){+.+.}-{3:3}, at: snd_seq_midisynth_remove+0x68/0x4e0 sound/core/seq/seq_midi.c:432 2 locks held by kworker/0:11/4834: #0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc9000328fd00 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 3 locks held by kworker/1:10/10262: #0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc900040c7d00 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 #2: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #2: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845 2 locks held by kworker/1:12/10266: #0: ffff888016c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc900041d7d00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 8 locks held by syz.0.1654/11534: #0: ffff8880649940f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056 #1: ffff88801d94a460 (sb_writers#23){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590 #2: ffff8880772bf288 (&buffer->mutex){+.+.}-{3:3}, at: configfs_write_iter+0x7d/0x400 fs/configfs/file.c:226 #3: ffff88801abed278 (&p->frag_sem){++++}-{3:3}, at: flush_write_buffer fs/configfs/file.c:205 [inline] #3: ffff88801abed278 (&p->frag_sem){++++}-{3:3}, at: configfs_write_iter+0x20e/0x400 fs/configfs/file.c:229 #4: ffff888074961310 (&gi->lock){+.+.}-{3:3}, at: gadget_dev_desc_UDC_store+0xed/0x2e0 drivers/usb/gadget/configfs.c:276 #5: ffffffff8ced1388 (udc_lock){+.+.}-{3:3}, at: usb_gadget_unregister_driver+0x56/0x4c0 drivers/usb/gadget/udc/core.c:1651 #6: ffff888075a58200 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline] #6: ffff888075a58200 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1064 [inline] #6: ffff888075a58200 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa1/0x710 drivers/base/dd.c:1279 #7: ffffffff8d3bcca8 (register_mutex#7){+.+.}-{3:3}, at: snd_seq_midisynth_remove+0x68/0x4e0 sound/core/seq/seq_midi.c:432 5 locks held by syz.6.1656/11543: #0: ffff88805feed4f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056 #1: ffff88801d94a460 (sb_writers#23){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590 #2: ffff88805f8f6288 (&buffer->mutex){+.+.}-{3:3}, at: configfs_write_iter+0x7d/0x400 fs/configfs/file.c:226 #3: ffff88801abed278 (&p->frag_sem){++++}-{3:3}, at: flush_write_buffer fs/configfs/file.c:205 [inline] #3: ffff88801abed278 (&p->frag_sem){++++}-{3:3}, at: configfs_write_iter+0x20e/0x400 fs/configfs/file.c:229 #4: ffff888074961310 (&gi->lock){+.+.}-{3:3}, at: gadget_dev_desc_UDC_store+0xed/0x2e0 drivers/usb/gadget/configfs.c:276 5 locks held by syz.3.1693/11668: #0: ffff88807c9c9770 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056 #1: ffff88801d94a460 (sb_writers#23){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590 #2: ffff88801ab9ca88 (&buffer->mutex){+.+.}-{3:3}, at: configfs_write_iter+0x7d/0x400 fs/configfs/file.c:226 #3: ffff88801abed278 (&p->frag_sem){++++}-{3:3}, at: flush_write_buffer fs/configfs/file.c:205 [inline] #3: ffff88801abed278 (&p->frag_sem){++++}-{3:3}, at: configfs_write_iter+0x20e/0x400 fs/configfs/file.c:229 #4: ffff888074961310 (&gi->lock){+.+.}-{3:3}, at: gadget_dev_desc_UDC_store+0xed/0x2e0 drivers/usb/gadget/configfs.c:276 1 lock held by syz.7.1749/11956: #0: ffffffff8ced1388 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604 1 lock held by syz.8.1763/12042: #0: ffffffff8ced1388 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604 5 locks held by syz.9.1735/12066: #0: ffff88807da7d270 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056 #1: ffff88801d94a460 (sb_writers#23){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590 #2: ffff88802fe67088 (&buffer->mutex){+.+.}-{3:3}, at: configfs_write_iter+0x7d/0x400 fs/configfs/file.c:226 #3: ffff88801abed278 (&p->frag_sem){++++}-{3:3}, at: flush_write_buffer fs/configfs/file.c:205 [inline] #3: ffff88801abed278 (&p->frag_sem){++++}-{3:3}, at: configfs_write_iter+0x20e/0x400 fs/configfs/file.c:229 #4: ffff888074961310 (&gi->lock){+.+.}-{3:3}, at: gadget_dev_desc_UDC_store+0xed/0x2e0 drivers/usb/gadget/configfs.c:276 1 lock held by syz.5.1849/12514: #0: ffffffff8ced1388 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604 5 locks held by syz.1.1868/12630: #0: ffff8880224719f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056 #1: ffff88801d94a460 (sb_writers#23){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590 #2: ffff88807a1d4288 (&buffer->mutex){+.+.}-{3:3}, at: configfs_write_iter+0x7d/0x400 fs/configfs/file.c:226 #3: ffff88801abed278 (&p->frag_sem){++++}-{3:3}, at: flush_write_buffer fs/configfs/file.c:205 [inline] #3: ffff88801abed278 (&p->frag_sem){++++}-{3:3}, at: configfs_write_iter+0x20e/0x400 fs/configfs/file.c:229 #4: ffff888074961310 (&gi->lock){+.+.}-{3:3}, at: os_desc_b_vendor_code_store+0xab/0x160 drivers/usb/gadget/configfs.c:835 1 lock held by syz.4.1913/12868: #0: ffffffff8ced1388 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604 1 lock held by syz.2.1929/13002: #0: ffffffff8ced1388 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604 1 lock held by syz.0.1930/13020: #0: ffffffff8ced1388 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604 1 lock held by syz.6.1933/13158: #0: ffffffff8ced1388 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604 1 lock held by syz.3.1926/13168: #0: ffffffff8ced1388 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604 1 lock held by syz.7.1934/13371: #0: ffffffff8ced1388 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604 1 lock held by syz.8.1935/13411: #0: ffffffff8ced1388 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604 1 lock held by syz.9.1936/13413: #0: ffffffff8ced1388 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604 1 lock held by syz.1.1940/13453: #0: ffffffff8ced1388 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604 2 locks held by kworker/u4:26/13475: 1 lock held by syz.5.1943/13479: #0: ffffffff8ced1388 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604 1 lock held by syz.4.1939/13491: #0: ffffffff8ced1388 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604 1 lock held by syz.2.1946/13521: #0: ffffffff8ced1388 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604 1 lock held by syz.0.1945/13523: #0: ffffffff8ced1388 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604 1 lock held by syz.3.1947/13541: #0: ffffffff8ced1388 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604 1 lock held by syz.6.1948/13569: #0: ffffffff8ced1388 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604 1 lock held by syz.7.1951/13597: #0: ffffffff8ced1388 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604 1 lock held by syz.8.1952/13622: #0: ffffffff8ced1388 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604 1 lock held by syz.9.1953/13638: #0: ffffffff8ced1388 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604 1 lock held by syz.1.1954/13653: #0: ffffffff8ced1388 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604 1 lock held by syz.5.1955/13672: #0: ffffffff8ced1388 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604 1 lock held by syz.4.1956/13693: #0: ffffffff8ced1388 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604 2 locks held by syz-executor/13694: #0: ffffffff8d44d008 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:699 [inline] #0: ffffffff8d44d008 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3443 #1: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #1: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a5/0x750 kernel/rcu/tree_exp.h:845 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: 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 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 13467 Comm: kworker/u4:19 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Workqueue: bat_events batadv_nc_worker RIP: 0010:arch_irqs_disabled_flags arch/x86/include/asm/irqflags.h:127 [inline] RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:134 [inline] RIP: 0010:lock_release+0x57e/0x8a0 kernel/locking/lockdep.c:5646 Code: a5 7e 83 f8 01 0f 85 83 00 00 00 4c 8b 64 24 50 43 c6 44 2c 04 00 48 c7 84 24 80 00 00 00 00 00 00 00 9c 8f 84 24 80 00 00 00 84 24 80 00 00 00 00 02 00 00 43 c6 44 2c 04 f8 75 6f 41 f7 c7 RSP: 0018:ffffc90003d0fac0 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 3c2807179fe6f01a RCX: 4fddde68a8380000 RDX: 0000000000000002 RSI: ffffffff8a2b3e80 RDI: ffffffff8a7a4540 RBP: ffffc90003d0fbd0 R08: ffffffff8d8b122f R09: 1ffffffff1b16245 R10: dffffc0000000000 R11: fffffbfff1b16246 R12: 1ffff920007a1f64 R13: dffffc0000000000 R14: ffff888029b16420 R15: 0000000000000246 FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555d8499ef70 CR3: 000000001b1a0000 CR4: 00000000003506f0 DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083 DR3: ffffffffefffff15 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_read_unlock include/linux/rcupdate.h:773 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:416 [inline] batadv_nc_worker+0x255/0x5c0 net/batman-adv/network-coding.c:723 process_one_work+0x867/0xff0 kernel/workqueue.c:2310 worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457 kthread+0x42e/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287