INFO: task udevd:2861 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:24680 pid:2861 tgid:2861 ppid:1 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0xeb0/0x3e50 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] schedule+0xdd/0x390 kernel/sched/core.c:6964 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7021 rwsem_down_read_slowpath+0x5dc/0xb30 kernel/locking/rwsem.c:1086 __down_read_common kernel/locking/rwsem.c:1261 [inline] __down_read kernel/locking/rwsem.c:1274 [inline] down_read+0xed/0x460 kernel/locking/rwsem.c:1539 kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1185 d_revalidate fs/namei.c:977 [inline] d_revalidate fs/namei.c:973 [inline] lookup_fast+0x3c7/0x600 fs/namei.c:1827 walk_component fs/namei.c:2225 [inline] link_path_walk+0x7a8/0x1b30 fs/namei.c:2597 path_lookupat+0x74/0xc40 fs/namei.c:2753 filename_lookup+0x202/0x590 fs/namei.c:2783 do_readlinkat+0xd1/0x390 fs/stat.c:576 __do_sys_readlink fs/stat.c:613 [inline] __se_sys_readlink fs/stat.c:610 [inline] __x64_sys_readlink+0x78/0xc0 fs/stat.c:610 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xc9/0x570 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f05a44f73a7 RSP: 002b:00007ffc71b3ed08 EFLAGS: 00000246 ORIG_RAX: 0000000000000059 RAX: ffffffffffffffda RBX: 00007ffc71b3f1e0 RCX: 00007f05a44f73a7 RDX: 0000000000000400 RSI: 00007ffc71b3ed10 RDI: 00007ffc71b3f1e0 RBP: 00007ffc71b3ed10 R08: 0000000000000075 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000400 R13: 000055e098731100 R14: 0000000000000001 R15: 00007ffc71b40ae0 INFO: task kworker/0:5:5235 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:5 state:D stack:22824 pid:5235 tgid:5235 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0xeb0/0x3e50 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] schedule+0xdd/0x390 kernel/sched/core.c:6964 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7021 rwsem_down_write_slowpath+0x530/0x1280 kernel/locking/rwsem.c:1185 __down_write_common kernel/locking/rwsem.c:1317 [inline] __down_write kernel/locking/rwsem.c:1326 [inline] down_write+0x1c7/0x1f0 kernel/locking/rwsem.c:1591 kernfs_add_one+0x38/0x850 fs/kernfs/dir.c:796 kernfs_create_dir_ns+0xfc/0x1a0 fs/kernfs/dir.c:1098 sysfs_create_dir_ns+0x13a/0x2b0 fs/sysfs/dir.c:59 create_dir lib/kobject.c:73 [inline] kobject_add_internal+0x2c8/0x930 lib/kobject.c:240 kobject_add_varg lib/kobject.c:374 [inline] kobject_add+0x16a/0x1e0 lib/kobject.c:426 device_add+0x294/0x1950 drivers/base/core.c:3627 cdev_device_add+0x12b/0x270 fs/char_dev.c:556 evdev_connect+0x3a8/0x4b0 drivers/input/evdev.c:1383 input_attach_handler.isra.0+0x177/0x1e0 drivers/input/input.c:994 input_register_device.cold+0x139/0x375 drivers/input/input.c:2378 usb_probe+0x1226/0x17c0 drivers/input/misc/yealink.c:928 usb_probe_interface+0x303/0x8f0 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:581 [inline] really_probe+0x241/0xa60 drivers/base/dd.c:659 __driver_probe_device+0x1de/0x400 drivers/base/dd.c:801 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:831 __device_attach_driver+0x1df/0x340 drivers/base/dd.c:959 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1031 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1086 bus_probe_device+0x64/0x160 drivers/base/bus.c:574 device_add+0x11d9/0x1950 drivers/base/core.c:3689 usb_set_configuration+0xd97/0x1c60 drivers/usb/core/message.c:2210 usb_generic_driver_probe+0xa1/0xe0 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+0x241/0xa60 drivers/base/dd.c:659 __driver_probe_device+0x1de/0x400 drivers/base/dd.c:801 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:831 __device_attach_driver+0x1df/0x340 drivers/base/dd.c:959 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1031 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1086 bus_probe_device+0x64/0x160 drivers/base/bus.c:574 device_add+0x11d9/0x1950 drivers/base/core.c:3689 usb_new_device.cold+0x685/0x115c 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+0x314d/0x4af0 drivers/usb/core/hub.c:5953 process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x5da/0xe40 kernel/workqueue.c:3421 kthread+0x3b3/0x730 kernel/kthread.c:463 ret_from_fork+0x6c3/0xa20 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 INFO: task syz.1.269:6338 blocked for more than 145 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.269 state:D stack:28472 pid:6338 tgid:6338 ppid:2968 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0xeb0/0x3e50 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] schedule+0xdd/0x390 kernel/sched/core.c:6964 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7021 rwsem_down_write_slowpath+0x530/0x1280 kernel/locking/rwsem.c:1185 __down_write_common kernel/locking/rwsem.c:1317 [inline] __down_write kernel/locking/rwsem.c:1326 [inline] down_write+0x1c7/0x1f0 kernel/locking/rwsem.c:1591 kernfs_remove_by_name_ns+0x3d/0xf0 fs/kernfs/dir.c:1717 sysfs_remove_file include/linux/sysfs.h:780 [inline] driver_remove_file drivers/base/driver.c:201 [inline] driver_remove_file+0x4a/0x60 drivers/base/driver.c:197 remove_bind_files drivers/base/bus.c:642 [inline] bus_remove_driver+0x248/0x2e0 drivers/base/bus.c:780 driver_unregister+0x76/0xb0 drivers/base/driver.c:277 usb_gadget_unregister_driver+0x49/0x70 drivers/usb/gadget/udc/core.c:1751 raw_release+0x19b/0x260 drivers/usb/gadget/legacy/raw_gadget.c:463 __fput+0x3ff/0xb40 fs/file_table.c:468 task_work_run+0x150/0x240 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:44 [inline] exit_to_user_mode_loop+0xdb/0x430 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+0x4a8/0x570 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f72fe7dbf79 RSP: 002b:00007ffe30bf2408 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007ffe30bf24f0 RCX: 00007f72fe7dbf79 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 000000000002f951 R08: 0000000000000001 R09: 0000000000000000 R10: 0000001b2d420000 R11: 0000000000000246 R12: 00007ffe30bf2530 R13: 00007f72fea55fac R14: 000000000003004f R15: 00007f72fea55fa0 INFO: task syz.3.272:6345 blocked for more than 145 seconds. Not tainted syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.272 state:D stack:27640 pid:6345 tgid:6344 ppid:2970 task_flags:0x40044c flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0xeb0/0x3e50 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] schedule+0xdd/0x390 kernel/sched/core.c:6964 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7021 rwsem_down_write_slowpath+0x530/0x1280 kernel/locking/rwsem.c:1185 __down_write_common kernel/locking/rwsem.c:1317 [inline] __down_write kernel/locking/rwsem.c:1326 [inline] down_write+0x1c7/0x1f0 kernel/locking/rwsem.c:1591 kernfs_remove_by_name_ns+0x3d/0xf0 fs/kernfs/dir.c:1717 sysfs_remove_file include/linux/sysfs.h:780 [inline] driver_remove_file drivers/base/driver.c:201 [inline] driver_remove_file+0x4a/0x60 drivers/base/driver.c:197 remove_bind_files drivers/base/bus.c:642 [inline] bus_remove_driver+0x248/0x2e0 drivers/base/bus.c:780 driver_unregister+0x76/0xb0 drivers/base/driver.c:277 usb_gadget_unregister_driver+0x49/0x70 drivers/usb/gadget/udc/core.c:1751 raw_release+0x19b/0x260 drivers/usb/gadget/legacy/raw_gadget.c:463 __fput+0x3ff/0xb40 fs/file_table.c:468 task_work_run+0x150/0x240 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x829/0x2a30 kernel/exit.c:971 do_group_exit+0xd5/0x2a0 kernel/exit.c:1112 get_signal+0x1ec7/0x21e0 kernel/signal.c:3034 arch_do_signal_or_restart+0x91/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x7e/0x430 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+0x4a8/0x570 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f71a151bc0b RSP: 002b:00007f719ff6cf00 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: fffffffffffffffc RBX: 0000000000000004 RCX: 00007f71a151bc0b RDX: 00007f719ff6dfd0 RSI: 0000000080085502 RDI: 0000000000000004 RBP: 00007f719ff6dfd0 R08: 00000000000008c5 R09: 00007f719ff6cfc8 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000080085502 R13: 0000000800000000 R14: 00000000000008c5 R15: 00007f71a15d076a INFO: task syz.0.273:6350 blocked for more than 146 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.273 state:D stack:28704 pid:6350 tgid:6349 ppid:2975 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0xeb0/0x3e50 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] schedule+0xdd/0x390 kernel/sched/core.c:6964 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7021 rwsem_down_write_slowpath+0x530/0x1280 kernel/locking/rwsem.c:1185 __down_write_common kernel/locking/rwsem.c:1317 [inline] __down_write kernel/locking/rwsem.c:1326 [inline] down_write+0x1c7/0x1f0 kernel/locking/rwsem.c:1591 kernfs_add_one+0x38/0x850 fs/kernfs/dir.c:796 kernfs_create_dir_ns+0xfc/0x1a0 fs/kernfs/dir.c:1098 sysfs_create_dir_ns+0x13a/0x2b0 fs/sysfs/dir.c:59 create_dir lib/kobject.c:73 [inline] kobject_add_internal+0x2c8/0x930 lib/kobject.c:240 kobject_add_varg lib/kobject.c:374 [inline] kobject_init_and_add+0x121/0x180 lib/kobject.c:457 bus_add_driver+0x186/0x5b0 drivers/base/bus.c:708 driver_register+0x1e2/0x360 drivers/base/driver.c:249 usb_gadget_register_driver_owner+0x132/0x210 drivers/usb/gadget/udc/core.c:1719 raw_ioctl_run drivers/usb/gadget/legacy/raw_gadget.c:596 [inline] raw_ioctl+0x1a85/0x2b80 drivers/usb/gadget/legacy/raw_gadget.c:1307 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xc9/0x570 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff12347bc0b RSP: 002b:00007ff121eccf00 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007ff12347bc0b RDX: 0000000000000000 RSI: 0000000000005501 RDI: 0000000000000003 RBP: 00007ff121ecdfd0 R08: 0000000000000001 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000200000002480 R14: 0000000000000000 R15: 0000000000000000 INFO: task syz.4.274:6352 blocked for more than 147 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.274 state:D stack:28760 pid:6352 tgid:6351 ppid:2973 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0xeb0/0x3e50 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] schedule+0xdd/0x390 kernel/sched/core.c:6964 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7021 rwsem_down_write_slowpath+0x530/0x1280 kernel/locking/rwsem.c:1185 __down_write_common kernel/locking/rwsem.c:1317 [inline] __down_write kernel/locking/rwsem.c:1326 [inline] down_write+0x1c7/0x1f0 kernel/locking/rwsem.c:1591 kernfs_add_one+0x38/0x850 fs/kernfs/dir.c:796 kernfs_create_dir_ns+0xfc/0x1a0 fs/kernfs/dir.c:1098 sysfs_create_dir_ns+0x13a/0x2b0 fs/sysfs/dir.c:59 create_dir lib/kobject.c:73 [inline] kobject_add_internal+0x2c8/0x930 lib/kobject.c:240 kobject_add_varg lib/kobject.c:374 [inline] kobject_init_and_add+0x121/0x180 lib/kobject.c:457 bus_add_driver+0x186/0x5b0 drivers/base/bus.c:708 driver_register+0x1e2/0x360 drivers/base/driver.c:249 usb_gadget_register_driver_owner+0x132/0x210 drivers/usb/gadget/udc/core.c:1719 raw_ioctl_run drivers/usb/gadget/legacy/raw_gadget.c:596 [inline] raw_ioctl+0x1a85/0x2b80 drivers/usb/gadget/legacy/raw_gadget.c:1307 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xc9/0x570 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fdab4e0bc0b RSP: 002b:00007fdab385cf00 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fdab4e0bc0b RDX: 0000000000000000 RSI: 0000000000005501 RDI: 0000000000000003 RBP: 00007fdab385dfd0 R08: 0000000000000001 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000200000000140 R14: 0000000000000001 R15: 0000000000000000 INFO: task syz.2.275:6354 blocked for more than 148 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.275 state:D stack:29352 pid:6354 tgid:6353 ppid:2971 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0xeb0/0x3e50 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] schedule+0xdd/0x390 kernel/sched/core.c:6964 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7021 rwsem_down_write_slowpath+0x530/0x1280 kernel/locking/rwsem.c:1185 __down_write_common kernel/locking/rwsem.c:1317 [inline] __down_write kernel/locking/rwsem.c:1326 [inline] down_write+0x1c7/0x1f0 kernel/locking/rwsem.c:1591 kernfs_add_one+0x38/0x850 fs/kernfs/dir.c:796 kernfs_create_dir_ns+0xfc/0x1a0 fs/kernfs/dir.c:1098 sysfs_create_dir_ns+0x13a/0x2b0 fs/sysfs/dir.c:59 create_dir lib/kobject.c:73 [inline] kobject_add_internal+0x2c8/0x930 lib/kobject.c:240 kobject_add_varg lib/kobject.c:374 [inline] kobject_init_and_add+0x121/0x180 lib/kobject.c:457 bus_add_driver+0x186/0x5b0 drivers/base/bus.c:708 driver_register+0x1e2/0x360 drivers/base/driver.c:249 usb_gadget_register_driver_owner+0x132/0x210 drivers/usb/gadget/udc/core.c:1719 raw_ioctl_run drivers/usb/gadget/legacy/raw_gadget.c:596 [inline] raw_ioctl+0x1a85/0x2b80 drivers/usb/gadget/legacy/raw_gadget.c:1307 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xc9/0x570 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6fdb87bc0b RSP: 002b:00007f6fda2ccf00 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f6fdb87bc0b RDX: 0000000000000000 RSI: 0000000000005501 RDI: 0000000000000003 RBP: 00007f6fda2cdfd0 R08: 0000000000000001 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000200000000000 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 5 locks held by kworker/0:0/9: 1 lock held by khungtaskd/30: #0: ffffffff894da3a0 ( rcu_read_lock ){....}-{1:3} , at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] , at: rcu_read_lock include/linux/rcupdate.h:867 [inline] , at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 8 locks held by kworker/0:2/2809: 1 lock held by udevd/2861: #0: ffff888100ac5988 ( &root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1185 2 locks held by getty/2923: #0: ffff888108a930a0 ( &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+0x419/0x1500 drivers/tty/n_tty.c:2211 1 lock held by syz-executor/2968: #0: ffff888100ac5988 ( &root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_dop_revalidate+0x397/0x740 fs/kernfs/dir.c:1167 1 lock held by syz-executor/2970: #0: ffff888100ac5988 ( &root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_dop_revalidate+0x397/0x740 fs/kernfs/dir.c:1167 1 lock held by syz-executor/2971: #0: ffff888100ac5988 (&root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_dop_revalidate+0x397/0x740 fs/kernfs/dir.c:1167 1 lock held by syz-executor/2973: #0: ffff888100ac5988 (&root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_dop_revalidate+0x397/0x740 fs/kernfs/dir.c:1167 1 lock held by syz-executor/2975: #0: ffff888100ac5988 ( &root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_dop_revalidate+0x397/0x740 fs/kernfs/dir.c:1167 3 locks held by kworker/0:3/5228: 4 locks held by kworker/0:4/5230: 1 lock held by udevd/5231: #0: ffff888100ac5988 (&root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1185 7 locks held by kworker/0:5/5235: #0: ffff888105afc548 ( (wq_completion)usb_hub_wq ){+.+.}-{0:0} , at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232 #1: ffffc9000214fca8 ((work_completion)(&hub->events) ){+.+.}-{0:0} , at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233 #2: ffff88810a798198 (&dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:895 [inline] , at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899 #3: ffff8881198dd198 ( &dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:895 [inline] , at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1006 #4: ffff88811beee160 (&dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:895 [inline] , at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1006 #5: ffffffff8a2e1068 ( input_mutex ){+.+.}-{4:4} , at: class_mutex_intr_constructor include/linux/mutex.h:255 [inline] , at: input_register_device.cold+0x5b/0x375 drivers/input/input.c:2374 #6: ffff888100ac5988 (&root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_add_one+0x38/0x850 fs/kernfs/dir.c:796 4 locks held by udevd/5249: #0: ffff888115aa4c30 ( &p->lock ){+.+.}-{4:4} , at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:182 #1: ffff88811a5f8088 (&of->mutex #2 ){+.+.}-{4:4} , at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172 #2: ffff888126691968 (kn->active #21){++++}-{0:0} , at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] , at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:173 #3: ffff8881198dd198 ( &dev->mutex ){....}-{4:4} , at: device_lock_interruptible include/linux/device.h:900 [inline] , at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 6 locks held by kworker/0:7/6122: #0: ffff888105afc548 ((wq_completion)usb_hub_wq ){+.+.}-{0:0} , at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232 #1: ffffc90012c0fca8 ( (work_completion)(&hub->events) ){+.+.}-{0:0} , at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233 #2: ffff88810a7c8198 (&dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:895 [inline] , at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899 #3: ffff888119900198 ( &dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:895 [inline] , at: usb_disconnect+0x10a/0x9a0 drivers/usb/core/hub.c:2336 #4: ffff88810f343160 ( &dev->mutex){....}-{4:4} , at: device_lock include/linux/device.h:895 [inline] , at: __device_driver_lock drivers/base/dd.c:1104 [inline] , at: device_release_driver_internal+0xaa/0x600 drivers/base/dd.c:1302 #5: ffff888100ac5988 ( &root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_remove_by_name_ns+0x3d/0xf0 fs/kernfs/dir.c:1717 1 lock held by syz.1.269/6338: #0: ffff888100ac5988 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_remove_by_name_ns+0x3d/0xf0 fs/kernfs/dir.c:1717 1 lock held by syz.3.272/6345: #0: ffff888100ac5988 (&root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_remove_by_name_ns+0x3d/0xf0 fs/kernfs/dir.c:1717 1 lock held by syz.0.273/6350: #0: ffff888100ac5988 (&root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_add_one+0x38/0x850 fs/kernfs/dir.c:796 1 lock held by syz.4.274/6352: #0: ffff888100ac5988 ( &root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_add_one+0x38/0x850 fs/kernfs/dir.c:796 1 lock held by syz.2.275/6354: #0: ffff888100ac5988 ( &root->kernfs_rwsem ){++++}-{4:4}, at: kernfs_add_one+0x38/0x850 fs/kernfs/dir.c:796 1 lock held by syz-executor/6355: #0: ffff888100ac5988 (&root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1185 1 lock held by syz-executor/6356: #0: ffff888100ac5988 (&root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1185 1 lock held by syz-executor/6357: #0: ffff888100ac5988 ( &root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1185 1 lock held by syz-executor/6358: #0: ffff888100ac5988 ( &root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1185 1 lock held by syz-executor/6359: #0: ffff888100ac5988 (&root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1185 ============================================= 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 02/12/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x141/0x190 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xcc3/0xfe0 kernel/hung_task.c:515 kthread+0x3b3/0x730 kernel/kthread.c:463 ret_from_fork+0x6c3/0xa20 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: yealink 3-1:36.0: unexpected response 0 NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 2809 Comm: kworker/0:2 Not tainted syzkaller #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: events_power_efficient gc_worker RIP: 0010:io_serial_out+0x8f/0xb0 drivers/tty/serial/8250/8250_port.c:407 Code: 48 8d 7d 40 44 89 e1 48 b8 00 00 00 00 00 fc ff df 48 89 fa d3 e3 48 c1 ea 03 80 3c 02 00 75 1c 66 03 5d 40 44 89 e8 89 da ee <5b> 5d 41 5c 41 5d c3 cc cc cc cc e8 d1 6a 01 ff eb a0 e8 5a 6b 01 RSP: 0018:ffffc90000007450 EFLAGS: 00000002 RAX: 0000000000000032 RBX: 00000000000003f8 RCX: 0000000000000000 RDX: 00000000000003f8 RSI: ffffffff8311c005 RDI: ffffffff93f14fc0 RBP: ffffffff93f14f80 R08: 0000000000000001 R09: 000000000000001f R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000032 R14: 0000000000000010 R15: ffffffff8311bfa0 FS: 0000000000000000(0000) GS:ffff88826896a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000003a40 CR3: 00000000092a8000 CR4: 00000000003506f0 Call Trace: serial_port_out include/linux/serial_core.h:811 [inline] serial8250_console_putchar drivers/tty/serial/8250/8250_port.c:3192 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3264 [inline] serial8250_console_write+0xde8/0x1900 drivers/tty/serial/8250/8250_port.c:3342 console_emit_next_record kernel/printk/printk.c:3129 [inline] console_flush_one_record+0x790/0xe50 kernel/printk/printk.c:3215 console_flush_all kernel/printk/printk.c:3289 [inline] __console_flush_and_unlock kernel/printk/printk.c:3319 [inline] console_unlock+0x103/0x260 kernel/printk/printk.c:3359 vprintk_emit+0x407/0x6b0 kernel/printk/printk.c:2426 dev_vprintk_emit+0x394/0x3e0 drivers/base/core.c:4914 dev_printk_emit+0xd2/0x10d drivers/base/core.c:4925 __dev_printk+0xcb/0x100 drivers/base/core.c:4937 _dev_err+0xef/0x127 drivers/base/core.c:4980 urb_irq_callback.cold+0x81/0xfd drivers/input/misc/yealink.c:435 __usb_hcd_giveback_urb+0x38d/0x610 drivers/usb/core/hcd.c:1657 usb_hcd_giveback_urb+0x3ca/0x4a0 drivers/usb/core/hcd.c:1741 dummy_timer+0xd85/0x3670 drivers/usb/gadget/udc/dummy_hcd.c:1995 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x516/0x990 kernel/time/hrtimer.c:1841 hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1858 handle_softirqs+0x1dd/0x8f0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xed/0x150 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0x8f/0xb0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_acquire+0x5e/0x330 kernel/locking/lockdep.c:5872 Code: 05 7b 34 3d 0b 83 f8 07 0f 87 a4 02 00 00 48 0f a3 05 06 aa 3e 09 0f 82 6f 02 00 00 8b 35 9e b6 3e 09 85 f6 0f 85 8a 00 00 00 <48> 8b 44 24 30 65 48 2b 05 1d 34 3d 0b 0f 85 b8 02 00 00 48 83 c4 RSP: 0018:ffffc900047cfa78 EFLAGS: 00000206 RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000002 RDX: 0000000000000000 RSI: ffffffff88dcbbf7 RDI: ffffffff878e97a0 RBP: ffffffff894da3a0 R08: 000000001c08614a R09: 0000000000000007 R10: 0000000000000200 R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] gc_worker+0x222/0x1630 net/netfilter/nf_conntrack_core.c:1546 process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x5da/0xe40 kernel/workqueue.c:3421 kthread+0x3b3/0x730 kernel/kthread.c:463 ret_from_fork+0x6c3/0xa20 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246