INFO: task kworker/1:0:23 blocked for more than 143 seconds. Not tainted 6.16.0-rc4-syzkaller-00314-gb4b4dbfa96de #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:0 state:D stack:22104 pid:23 tgid:23 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: events kernfs_notify_workfn Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x132a/0x3b10 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6878 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6935 rwsem_down_read_slowpath+0x62f/0xb60 kernel/locking/rwsem.c:1084 __down_read_common kernel/locking/rwsem.c:1248 [inline] __down_read kernel/locking/rwsem.c:1261 [inline] down_read+0xef/0x480 kernel/locking/rwsem.c:1526 kernfs_notify_workfn+0xff/0xb30 fs/kernfs/file.c:915 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5b3/0x6c0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task syz-executor.0:6522 blocked for more than 145 seconds. Not tainted 6.16.0-rc4-syzkaller-00314-gb4b4dbfa96de #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:26280 pid:6522 tgid:6522 ppid:3454 task_flags:0x40044c flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x132a/0x3b10 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6878 exp_funnel_lock+0x346/0x3c0 kernel/rcu/tree_exp.h:327 synchronize_rcu_expedited+0x28e/0x460 kernel/rcu/tree_exp.h:998 namespace_unlock+0x4ce/0x880 fs/namespace.c:1802 put_mnt_ns fs/namespace.c:6282 [inline] put_mnt_ns+0xee/0x130 fs/namespace.c:6274 free_nsproxy+0x3a/0x400 kernel/nsproxy.c:188 put_nsproxy include/linux/nsproxy.h:118 [inline] switch_task_namespaces+0xeb/0x100 kernel/nsproxy.c:241 do_exit+0x867/0x2bd0 kernel/exit.c:963 do_group_exit+0xd3/0x2a0 kernel/exit.c:1105 get_signal+0x2673/0x26d0 kernel/signal.c:3034 arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x7c/0xe0 kernel/entry/common.c:111 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x3e9/0x4b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f44beafb9da RSP: 002b:00007ffe30e72850 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 00007f44beafb9da RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007f44bec1d980 R08: 0000001b33360000 R09: 00007f44bea78000 R10: 0000000000000000 R11: 0000000000000293 R12: 000000000002aec4 R13: ffffffffffffffff R14: 00007f44be678000 R15: 00000000000299f6 Showing all locks held in the system: 2 locks held by kworker/u8:0/12: #0: ffff888100089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc900000cfd10 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 1 lock held by khungtaskd/30: #0: ffffffff890c7ec0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff890c7ec0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff890c7ec0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6770 7 locks held by kworker/1:1/37: #0: ffff8881066f3d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90000277d10 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff88810b3e5198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #2: ffff88810b3e5198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x5030 drivers/usb/core/hub.c:5894 #3: ffff888117a44198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #3: ffff888117a44198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1004 #4: ffff88811aaee160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #4: ffff88811aaee160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1004 #5: ffff888133f51a20 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #5: ffff888133f51a20 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1004 #6: ffffffff89e0c8a8 (input_mutex){+.+.}-{4:4}, at: class_mutex_intr_constructor include/linux/mutex.h:227 [inline] #6: ffffffff89e0c8a8 (input_mutex){+.+.}-{4:4}, at: input_register_device+0x98a/0x1130 drivers/input/input.c:2408 6 locks held by kworker/u8:2/38: 2 locks held by kworker/u8:5/312: #0: ffff888100089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000175fd10 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 7 locks held by kworker/0:2/1119: #0: ffff8881066f3d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90001ebfd10 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff88810b7ad198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #2: ffff88810b7ad198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x5030 drivers/usb/core/hub.c:5894 #3: ffff88811a174198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #3: ffff88811a174198 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0x10a/0x9c0 drivers/usb/core/hub.c:2335 #4: ffff8881056fb160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #4: ffff8881056fb160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1094 [inline] #4: ffff8881056fb160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xa4/0x620 drivers/base/dd.c:1292 #5: ffff88812bfb1a20 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #5: ffff88812bfb1a20 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1094 [inline] #5: ffff88812bfb1a20 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xa4/0x620 drivers/base/dd.c:1292 #6: ffffffff89e0c8a8 (input_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:225 [inline] #6: ffffffff89e0c8a8 (input_mutex){+.+.}-{4:4}, at: __input_unregister_device+0x156/0x470 drivers/input/input.c:2221 2 locks held by getty/2904: #0: ffff88811245f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900000432f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 3 locks held by kworker/0:3/6189: 7 locks held by kworker/1:6/6258: #0: ffff8881066f3d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90002f5fd10 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff88810b7bd198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #2: ffff88810b7bd198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x5030 drivers/usb/core/hub.c:5894 #3: ffff888116592198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #3: ffff888116592198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1004 #4: ffff88812df98160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #4: ffff88812df98160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1004 #5: ffff88811b8b9a20 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #5: ffff88811b8b9a20 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1004 #6: ffffffff89e0c8a8 (input_mutex){+.+.}-{4:4}, at: class_mutex_intr_constructor include/linux/mutex.h:227 [inline] #6: ffffffff89e0c8a8 (input_mutex){+.+.}-{4:4}, at: input_register_device+0x98a/0x1130 drivers/input/input.c:2408 9 locks held by kworker/1:7/6259: 2 locks held by kworker/u8:6/8090: 1 lock held by modprobe/8862: 1 lock held by modprobe/8863: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.16.0-rc4-syzkaller-00314-gb4b4dbfa96de #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xf70/0x12c0 kernel/hung_task.c:470 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5b3/0x6c0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 38 Comm: kworker/u8:2 Not tainted 6.16.0-rc4-syzkaller-00314-gb4b4dbfa96de #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: netns cleanup_net RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline] RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:124 [inline] RIP: 0010:lock_acquire kernel/locking/lockdep.c:5847 [inline] RIP: 0010:lock_acquire+0x119/0x350 kernel/locking/lockdep.c:5828 Code: 48 8b 74 24 68 48 89 df e8 54 2e 80 00 8b 0d 42 75 20 09 85 c9 0f 84 b1 00 00 00 65 8b 05 b7 a4 11 0b 85 c0 0f 85 a2 00 00 00 <65> 48 8b 05 37 65 11 0b 8b 90 a4 0a 00 00 85 d2 0f 85 8c 00 00 00 RSP: 0018:ffffc900001a8900 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffffff890c7ec0 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff813b02d1 RDI: fffffbfff1218fd8 RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 000000000000dad2 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888269262000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007eff88db0000 CR3: 0000000130546000 CR4: 00000000003506f0 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x37/0x50 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2381 [inline] slab_free mm/slub.c:4643 [inline] kfree+0x283/0x470 mm/slub.c:4842 slab_free_after_rcu_debug+0x60/0x2a0 mm/slub.c:4680 rcu_do_batch kernel/rcu/tree.c:2576 [inline] rcu_core+0x79c/0x14e0 kernel/rcu/tree.c:2832 handle_softirqs+0x208/0x8d0 kernel/softirq.c:579 do_softirq kernel/softirq.c:480 [inline] do_softirq+0xb2/0xf0 kernel/softirq.c:467 __local_bh_enable_ip+0x100/0x120 kernel/softirq.c:407 spin_unlock_bh include/linux/spinlock.h:396 [inline] addrconf_ifdown.isra.0+0x56f/0x1a90 net/ipv6/addrconf.c:3911 addrconf_notify+0x220/0x19e0 net/ipv6/addrconf.c:3780 notifier_call_chain+0xb9/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2230 call_netdevice_notifiers_extack net/core/dev.c:2268 [inline] call_netdevice_notifiers net/core/dev.c:2282 [inline] unregister_netdevice_many_notify+0x115c/0x2550 net/core/dev.c:12077 ops_exit_rtnl_list net/core/net_namespace.c:188 [inline] ops_undo_list+0x8fc/0xab0 net/core/net_namespace.c:249 cleanup_net+0x408/0x890 net/core/net_namespace.c:686 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5b3/0x6c0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245