INFO: task kworker/0:6:8269 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:6 state:D stack:23384 pid:8269 tgid:8269 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x145d/0x4a00 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6960 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0xc69/0x1ca0 kernel/locking/mutex.c:776 uevent_net_broadcast_untagged lib/kobject_uevent.c:317 [inline] kobject_uevent_net_broadcast lib/kobject_uevent.c:410 [inline] kobject_uevent_env+0xb88/0x1920 lib/kobject_uevent.c:608 device_add+0x1103/0x1980 drivers/base/core.c:3670 hid_add_device+0x31b/0x5c0 drivers/hid/hid-core.c:2951 usbhid_probe+0xd5d/0x1410 drivers/hid/usbhid/hid-core.c:1435 usb_probe_interface+0x303/0xa80 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:581 [inline] really_probe+0x241/0xb20 drivers/base/dd.c:659 __driver_probe_device+0x1de/0x470 drivers/base/dd.c:801 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:831 __device_attach_driver+0x1df/0x350 drivers/base/dd.c:959 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500 __device_attach+0x1e4/0x4e0 drivers/base/dd.c:1031 device_initial_probe+0xaa/0xc0 drivers/base/dd.c:1086 bus_probe_device+0x64/0x150 drivers/base/bus.c:574 device_add+0x116e/0x1980 drivers/base/core.c:3689 usb_set_configuration+0x1187/0x1e50 drivers/usb/core/message.c:2210 usb_generic_driver_probe+0xb1/0x110 drivers/usb/core/generic.c:250 usb_probe_device+0xef/0x400 drivers/usb/core/driver.c:291 call_driver_probe drivers/base/dd.c:581 [inline] really_probe+0x241/0xb20 drivers/base/dd.c:659 __driver_probe_device+0x1de/0x470 drivers/base/dd.c:801 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:831 __device_attach_driver+0x1df/0x350 drivers/base/dd.c:959 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500 __device_attach+0x1e4/0x4e0 drivers/base/dd.c:1031 device_initial_probe+0xaa/0xc0 drivers/base/dd.c:1086 bus_probe_device+0x64/0x150 drivers/base/bus.c:574 device_add+0x116e/0x1980 drivers/base/core.c:3689 usb_new_device+0xd07/0x1a90 drivers/usb/core/hub.c:2695 hub_port_connect drivers/usb/core/hub.c:5567 [inline] hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] port_event drivers/usb/core/hub.c:5871 [inline] hub_event+0x31bf/0x5420 drivers/usb/core/hub.c:5953 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x74f/0xa30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Showing all locks held in the system: 3 locks held by kworker/u8:0/12: #0: ffff888111a61148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232 #1: ffffc900000cfca0 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233 #2: ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x12/0x30 net/ipv6/addrconf.c:4734 2 locks held by kdevtmpfs/25: 1 lock held by khungtaskd/30: #0: ffffffff892cd6e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff892cd6e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff892cd6e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 3 locks held by kworker/1:1/38: #0: ffff8881026e3d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232 #1: ffffc90000287ca0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233 #2: ffff88810a799198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #2: ffff88810a799198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x5420 drivers/usb/core/hub.c:5899 5 locks held by kworker/u8:7/469: #0: ffff888100ac4948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232 #1: ffffc9000195fca0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233 #2: ffffffff8a6505b0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xad/0x900 net/core/net_namespace.c:670 #3: ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline] #3: ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x7e9/0xab0 net/core/net_namespace.c:248 #4: ffffffff892d8e38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x284/0x3c0 kernel/rcu/tree_exp.h:311 1 lock held by udevd/2857: 2 locks held by getty/2919: #0: ffff888115cc00a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900000452f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x1510 drivers/tty/n_tty.c:2211 3 locks held by kworker/0:3/5227: #0: ffff8881026e3d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232 #1: ffffc9000236fca0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233 #2: ffff88810a399198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #2: ffff88810a399198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x5420 drivers/usb/core/hub.c:5899 3 locks held by kworker/1:5/5390: 6 locks held by kworker/0:6/8269: 1 lock held by syz.1.901/8490: 2 locks held by syz-executor/8544: #0: ffffffff8a6505b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x31b/0x780 net/core/net_namespace.c:577 #1: ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #1: ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2083 2 locks held by syz-executor/8556: #0: ffffffff8a6505b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x31b/0x780 net/core/net_namespace.c:577 #1: ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #1: ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2083 2 locks held by syz-executor/8558: #0: ffffffff8a6505b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x31b/0x780 net/core/net_namespace.c:577 #1: ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #1: ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2083 2 locks held by syz-executor/8561: #0: ffffffff8a6505b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x31b/0x780 net/core/net_namespace.c:577 #1: ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #1: ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2083 2 locks held by syz-executor/8584: #0: ffffffff8a6505b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x31b/0x780 net/core/net_namespace.c:577 #1: ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #1: ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2083 1 lock held by syz-executor/8594: #0: ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x30c/0x1540 net/ipv4/devinet.c:978 1 lock held by syz-executor/8601: #0: ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x30c/0x1540 net/ipv4/devinet.c:978 1 lock held by syz-executor/8602: #0: ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x30c/0x1540 net/ipv4/devinet.c:978 1 lock held by syz-executor/8605: #0: ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x30c/0x1540 net/ipv4/devinet.c:978 1 lock held by syz-executor/8613: #0: ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x30c/0x1540 net/ipv4/devinet.c:978 1 lock held by syz-executor/8617: #0: ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x30c/0x1540 net/ipv4/devinet.c:978 1 lock held by syz-executor/8623: #0: ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x30c/0x1540 net/ipv4/devinet.c:978 1 lock held by syz-executor/8625: #0: ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x30c/0x1540 net/ipv4/devinet.c:978 1 lock held by syz-executor/8628: #0: ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x30c/0x1540 net/ipv4/devinet.c:978 1 lock held by syz-executor/8633: #0: ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x30c/0x1540 net/ipv4/devinet.c:978 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x133/0x180 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xe66/0x1180 kernel/hung_task.c:515 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x74f/0xa30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 8605 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/irqflags.h:158 [inline] RIP: 0010:lock_release+0x174/0x2d0 kernel/locking/lockdep.c:5892 Code: 4f 31 ce 88 e8 fd 5b fb 05 b8 ff ff ff ff 65 0f c1 05 98 4c 47 0b 83 f8 01 0f 85 03 01 00 00 9c 58 f6 c4 02 0f 85 ee 00 00 00 <41> f7 c5 00 02 00 00 74 01 fb 48 8b 44 24 10 65 48 2b 05 8d 08 47 RSP: 0018:ffffc900161af540 EFLAGS: 00000046 RAX: 0000000000000046 RBX: ffffffff892cd6e0 RCX: ffffc900161af54c RDX: 0000000000000003 RSI: ffffffff88ce314f RDI: ffffffff878a7300 RBP: ffff88823fff9c80 R08: 00000000bc3f320f R09: 00000000fbc3f320 R10: 0000000000000002 R11: ffff88810cf5e268 R12: ffffffff81e3fe97 R13: 0000000000000206 R14: ffff88810cf5d7c0 R15: 0000000000000004 FS: 0000000000000000(0000) GS:ffff888268bf4000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000056385e947331 CR3: 00000000090a6000 CR4: 00000000003506f0 Call Trace: rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock+0x1c/0x60 include/linux/rcupdate.h:897 lruvec_stat_mod_folio+0x2af/0x450 mm/memcontrol.c:791 __folio_mod_stat mm/rmap.c:1215 [inline] __folio_remove_rmap mm/rmap.c:1752 [inline] folio_remove_rmap_ptes+0x332/0x790 mm/rmap.c:1779 zap_present_folio_ptes mm/memory.c:1650 [inline] zap_present_ptes mm/memory.c:1708 [inline] do_zap_pte_range mm/memory.c:1810 [inline] zap_pte_range mm/memory.c:1854 [inline] zap_pmd_range mm/memory.c:1946 [inline] zap_pud_range mm/memory.c:1975 [inline] zap_p4d_range mm/memory.c:1996 [inline] unmap_page_range+0x18e2/0x3d50 mm/memory.c:2017 unmap_single_vma+0x153/0x240 mm/memory.c:2059 unmap_vmas+0x218/0x470 mm/memory.c:2101 exit_mmap+0x1b0/0xb60 mm/mmap.c:1277 __mmput kernel/fork.c:1173 [inline] mmput+0xdb/0x430 kernel/fork.c:1196 exit_mm kernel/exit.c:581 [inline] do_exit+0x7d7/0x2bd0 kernel/exit.c:959 do_group_exit+0xd3/0x2a0 kernel/exit.c:1112 get_signal+0x2671/0x26d0 kernel/signal.c:3034 arch_do_signal_or_restart+0x8f/0x7e0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x80/0x4f0 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x4bb/0x570 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc7e3471583 Code: Unable to access opcode bytes at 0x7fc7e3471559. RSP: 002b:00007ffe1d09d918 EFLAGS: 00000202 ORIG_RAX: 000000000000002c RAX: 0000000000000028 RBX: 00007fc7e41f4620 RCX: 00007fc7e3471583 RDX: 0000000000000028 RSI: 00007fc7e41f4670 RDI: 0000000000000003 RBP: 0000000000000001 R08: 00007ffe1d09d934 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003 R13: 0000000000000000 R14: 00007fc7e41f4670 R15: 0000000000000000