INFO: task kworker/1:4:5233 blocked for more than 143 seconds. Not tainted 6.14.0-rc6-syzkaller-g3a85c1011540 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:4 state:D stack:21280 pid:5233 tgid:5233 ppid:2 task_flags:0x4288060 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0x113d/0x35d0 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6857 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6914 __mutex_lock_common kernel/locking/mutex.c:662 [inline] __mutex_lock+0x6bd/0xb10 kernel/locking/mutex.c:730 rtnl_net_lock include/linux/rtnetlink.h:129 [inline] rtnl_net_dev_lock+0x146/0x360 net/core/dev.c:2119 unregister_netdev+0x15/0x60 net/core/dev.c:11965 usbnet_disconnect+0x109/0x500 drivers/net/usb/usbnet.c:1637 usb_unbind_interface+0x1da/0x9a0 drivers/usb/core/driver.c:458 device_remove drivers/base/dd.c:569 [inline] device_remove+0x122/0x170 drivers/base/dd.c:561 __device_release_driver drivers/base/dd.c:1273 [inline] device_release_driver_internal+0x44a/0x610 drivers/base/dd.c:1296 bus_remove_device+0x22f/0x420 drivers/base/bus.c:579 device_del+0x396/0x9f0 drivers/base/core.c:3855 usb_disable_device+0x368/0x7e0 drivers/usb/core/message.c:1418 usb_disconnect+0x2e1/0x920 drivers/usb/core/hub.c:2316 hub_port_connect drivers/usb/core/hub.c:5371 [inline] hub_port_connect_change drivers/usb/core/hub.c:5671 [inline] port_event drivers/usb/core/hub.c:5831 [inline] hub_event+0x1bed/0x4f40 drivers/usb/core/hub.c:5913 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3400 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff88ebe8c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] ffffffff88ebe8c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] ffffffff88ebe8c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6746 3 locks held by dhcpcd/2881: 2 locks held by getty/2901: #0: ffff888100eac0a0 (&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+0xfba/0x1480 drivers/tty/n_tty.c:2211 6 locks held by kworker/1:4/5233: #0: ffff8881066ad948 ((wq_completion)usb_hub_wq){+.+.}-{0:0} , at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3213 #1: ffffc900024e7d18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3214 #2: ffff88810b7b3198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline] ffff88810b7b3198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5859 #3: ffff88813dc38198 (&dev->mutex){....}-{4:4} , at: device_lock include/linux/device.h:1030 [inline] , at: usb_disconnect+0x10a/0x920 drivers/usb/core/hub.c:2307 #4: ffff88812b58d160 (&dev->mutex){....}-{4:4} , at: device_lock include/linux/device.h:1030 [inline] , at: __device_driver_lock drivers/base/dd.c:1095 [inline] , at: device_release_driver_internal+0xa4/0x610 drivers/base/dd.c:1293 #5: ffffffff8a1a0da8 (rtnl_mutex){+.+.}-{4:4} , at: rtnl_net_lock include/linux/rtnetlink.h:129 [inline] , at: rtnl_net_dev_lock+0x146/0x360 net/core/dev.c:2119 6 locks held by kworker/0:7/10325: #0: ffff8881066ad948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3213 #1: ffffc900129e7d18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3214 #2: ffff88810b7cb198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline] (&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5859 #3: ffff88812794f198 (&dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:1030 [inline] , at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 #4: ffff88813cc2b160 (&dev->mutex){....}-{4:4} , at: device_lock include/linux/device.h:1030 [inline] , at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 #5: ffffffff8a1a0da8 (rtnl_mutex){+.+.}-{4:4} , at: rtnl_net_lock_killable include/linux/rtnetlink.h:144 [inline] , at: register_netdev+0x18/0x50 net/core/dev.c:11053 6 locks held by kworker/0:0/18147: #0: ffff8881066ad948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3213 #1: ffffc9001358fd18 ((work_completion)(&hub->events) ){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3214 #2: ffff88810bb6b198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline] (&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5859 #3: ffff88811954a198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline] #3: ffff88811954a198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 #4: ffff88810cbe2160 (&dev->mutex){....}-{4:4} , at: device_lock include/linux/device.h:1030 [inline] , at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 #5: ffffffff8a1a0da8 (rtnl_mutex ){+.+.}-{4:4} , at: rtnl_net_lock_killable include/linux/rtnetlink.h:144 [inline] , at: register_netdev+0x18/0x50 net/core/dev.c:11053 6 locks held by kworker/1:5/23613: #0: ffff8881066ad948 ((wq_completion)usb_hub_wq ){+.+.}-{0:0} , at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3213 #1: ffffc90001ecfd18 ((work_completion)(&hub->events)){+.+.}-{0:0} , at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3214 #2: ffff88810bb83198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline] #2: ffff88810bb83198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5859 #3: ffff88811ee31198 (&dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:1030 [inline] , at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 #4: ffff88813dabd160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline] (&dev->mutex){....}-{4:4}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 #5: ffffffff8a1a0da8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock_killable include/linux/rtnetlink.h:144 [inline] (rtnl_mutex){+.+.}-{4:4}, at: register_netdev+0x18/0x50 net/core/dev.c:11053 4 locks held by udevd/26576: #0: ffff8881279de9e0 (&p->lock){+.+.}-{4:4} , at: seq_read_iter+0xd8/0x12b0 fs/seq_file.c:182 #1: ffff88811d9a3c88 (&of->mutex #2){+.+.}-{4:4} , at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff888112a98698 (kn->active#5 ){++++}-{0:0} , at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff88811ee31198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline] ffff88811ee31198 (&dev->mutex){....}-{4:4}, at: uevent_show+0x188/0x3b0 drivers/base/core.c:2730 4 locks held by udevd/26580: #0: ffff888128b38540 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xd8/0x12b0 fs/seq_file.c:182 #1: ffff88811939a888 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff8881158463c8 ( kn->active#5 ){++++}-{0:0} , at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff88811954a198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline] (&dev->mutex){....}-{4:4}, at: uevent_show+0x188/0x3b0 drivers/base/core.c:2730 3 locks held by kworker/u8:3/28655: #0: ffff88810f33c948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3213 #1: ffffc9000e39fd18 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0} , at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3214 #2: ffffffff8a1a0da8 ( rtnl_mutex ){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:129 [inline] ){+.+.}-{4:4}, at: addrconf_verify_work+0x12/0x30 net/ipv6/addrconf.c:4730 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.14.0-rc6-syzkaller-g3a85c1011540 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 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:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline] watchdog+0xf62/0x12b0 kernel/hung_task.c:399 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 13420 Comm: kworker/0:1 Not tainted 6.14.0-rc6-syzkaller-g3a85c1011540 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: events legacy_dvb_usb_read_remote_control RIP: 0010:write_comp_data+0x42/0x90 kernel/kcov.c:246 Code: a9 00 01 ff 00 74 1d f6 c4 01 74 67 a9 00 00 0f 00 75 60 a9 00 00 f0 00 75 59 8b 82 64 15 00 00 85 c0 74 4f 8b 82 40 15 00 00 <83> f8 03 75 44 48 8b 82 48 15 00 00 8b 92 44 15 00 00 48 8b 38 48 RSP: 0018:ffffc9001294f2b8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000005 RCX: ffffffff8715514d RDX: ffff88811d6957c0 RSI: 0000000000000004 RDI: 0000000000000001 RBP: ffffffff88125dc0 R08: 0000000000000001 R09: 0000000000000004 R10: 0000000000000001 R11: 0000000000ebdd38 R12: 0000000000000001 R13: 0000000000000001 R14: 0000000000000008 R15: ffffffff8728fd22 FS: 0000000000000000(0000) GS:ffff8881f5800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffff6359f28 CR3: 00000001169a8000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __sanitizer_cov_trace_switch+0x54/0x90 kernel/kcov.c:351 vsnprintf+0x17d/0x1180 lib/vsprintf.c:2788 snprintf+0xc8/0x100 lib/vsprintf.c:2937 print_caller kernel/printk/printk.c:1390 [inline] info_print_prefix+0x135/0x350 kernel/printk/printk.c:1409 record_print_text+0x141/0x400 kernel/printk/printk.c:1456 printk_get_next_message+0x2be/0x690 kernel/printk/printk.c:3008 console_emit_next_record kernel/printk/printk.c:3076 [inline] console_flush_all+0x6ec/0xc60 kernel/printk/printk.c:3210 __console_flush_and_unlock kernel/printk/printk.c:3269 [inline] console_unlock+0xd9/0x210 kernel/printk/printk.c:3309 vprintk_emit+0x424/0x6f0 kernel/printk/printk.c:2432 _printk+0xc8/0x100 kernel/printk/printk.c:2457 m920x_read drivers/media/usb/dvb-usb/m920x.c:40 [inline] m920x_rc_query+0x496/0x770 drivers/media/usb/dvb-usb/m920x.c:193 legacy_dvb_usb_read_remote_control+0x10a/0x500 drivers/media/usb/dvb-usb/dvb-usb-remote.c:123 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3400 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244