INFO: task dhcpcd:2889 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:dhcpcd state:D stack:23944 pid:2889 tgid:2889 ppid:2888 task_flags:0x400140 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x12fc/0x3b90 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 rpm_resume+0x59c/0x1310 drivers/base/power/runtime.c:854 rpm_resume+0x744/0x1310 drivers/base/power/runtime.c:912 __pm_runtime_resume+0xb6/0x170 drivers/base/power/runtime.c:1192 pm_runtime_resume_and_get include/linux/pm_runtime.h:526 [inline] usb_autopm_get_interface+0x20/0xe0 drivers/usb/core/driver.c:1864 usbnet_open+0x71/0xbe0 drivers/net/usb/usbnet.c:899 __dev_open+0x3a3/0x850 net/core/dev.c:1682 __dev_change_flags+0x55d/0x720 net/core/dev.c:9549 netif_change_flags+0x8d/0x160 net/core/dev.c:9612 dev_change_flags+0xb6/0x170 net/core/dev_api.c:68 devinet_ioctl+0x11d5/0x1f50 net/ipv4/devinet.c:1199 inet_ioctl+0x3a7/0x3f0 net/ipv4/af_inet.c:1001 sock_do_ioctl+0x118/0x280 net/socket.c:1238 sock_ioctl+0x42f/0x6a0 net/socket.c:1359 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:598 [inline] __se_sys_ioctl fs/ioctl.c:584 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:584 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4d0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f439b22d378 RSP: 002b:00007fffe68d3d28 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000008 RCX: 00007f439b22d378 RDX: 00007fffe68e3f20 RSI: 0000000000008914 RDI: 0000000000000008 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fffe68f40c0 R13: 00007f439b12d6c8 R14: 0000000000000028 R15: 0000000000008914 INFO: task kworker/1:6:5455 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:6 state:D stack:22136 pid:5455 tgid:5455 ppid:2 task_flags:0x4288060 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x12fc/0x3b90 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 rpm_resume+0x59c/0x1310 drivers/base/power/runtime.c:854 rpm_resume+0x744/0x1310 drivers/base/power/runtime.c:912 __pm_runtime_resume+0xb6/0x170 drivers/base/power/runtime.c:1192 pm_runtime_resume_and_get include/linux/pm_runtime.h:526 [inline] usb_autopm_get_interface+0x20/0xe0 drivers/usb/core/driver.c:1864 aqc111_write_cmd drivers/net/usb/aqc111.c:132 [inline] aqc111_write32_cmd drivers/net/usb/aqc111.c:180 [inline] aqc111_suspend+0x7f8/0xb20 drivers/net/usb/aqc111.c:1409 usb_suspend_interface drivers/usb/core/driver.c:1323 [inline] usb_suspend_both+0x2ff/0xc70 drivers/usb/core/driver.c:1445 usb_runtime_suspend+0x49/0x180 drivers/usb/core/driver.c:1997 __rpm_callback+0xc5/0x610 drivers/base/power/runtime.c:406 rpm_callback+0xea/0x200 drivers/base/power/runtime.c:457 rpm_suspend+0x2e1/0x11d0 drivers/base/power/runtime.c:695 __pm_runtime_suspend+0xba/0x1a0 drivers/base/power/runtime.c:1162 pm_runtime_put_sync_autosuspend include/linux/pm_runtime.h:695 [inline] usb_new_device+0x1025/0x1a60 drivers/usb/core/hub.c:2726 hub_port_connect drivers/usb/core/hub.c:5566 [inline] hub_port_connect_change drivers/usb/core/hub.c:5706 [inline] port_event drivers/usb/core/hub.c:5870 [inline] hub_event+0x2fce/0x5060 drivers/usb/core/hub.c:5952 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x56d/0x700 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Showing all locks held in the system: 6 locks held by kworker/0:0/9: #0: ffff88810768e548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc9000009fd10 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffff88810b76f198 ( &dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] &dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x5060 drivers/usb/core/hub.c:5898 #3: ffff88813989f198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #3: ffff88813989f198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1006 #4: ffff88811ff68160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #4: ffff88811ff68160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1006 #5: ffffffff8a5fc208 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock_killable include/linux/rtnetlink.h:145 [inline] #5: ffffffff8a5fc208 (rtnl_mutex){+.+.}-{4:4}, at: register_netdev+0x18/0x50 net/core/dev.c:11319 1 lock held by khungtaskd/30: #0: ffffffff892c76e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff892c76e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff892c76e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 6 locks held by kworker/1:2/1119: #0: ffff88810768e548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc90001b9fd10 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffff88810b397198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #2: ffff88810b397198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x5060 drivers/usb/core/hub.c:5898 #3: ffff888106eb6198 (&dev->mutex){....}-{4:4} , at: device_lock include/linux/device.h:911 [inline] , at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1006 #4: ffff888111e75160 (&dev->mutex){....}-{4:4} , at: device_lock include/linux/device.h:911 [inline] , at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1006 #5: ffffffff8a5fc208 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock_killable include/linux/rtnetlink.h:145 [inline] #5: ffffffff8a5fc208 (rtnl_mutex){+.+.}-{4:4}, at: register_netdev+0x18/0x50 net/core/dev.c:11319 1 lock held by klogd/2838: #0: ffff8881f59388d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x1f/0x30 kernel/sched/core.c:636 1 lock held by dhcpcd/2889: #0: ffffffff8a5fc208 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] ffffffff8a5fc208 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x26d/0x1f50 net/ipv4/devinet.c:1120 2 locks held by getty/2912: #0: ffff8881151f80a0 (&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 4 locks held by udevd/5199: #0: ffff88811db19418 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x12c0 fs/seq_file.c:182 #1: ffff8881359eec88 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172 #2: ffff888135c9ff08 (kn->active#23){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888135c9ff08 (kn->active#23){++++}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:173 #3: ffff888106eb6198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:916 [inline] #3: ffff888106eb6198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 4 locks held by udevd/5314: #0: ffff88813578dc30 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x12c0 fs/seq_file.c:182 #1: ffff8881155c2c88 (&of->mutex #2 ){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172 #2: ffff88811d0e1f08 (kn->active#26){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff88811d0e1f08 (kn->active#26){++++}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:173 #3: ffff888139972198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:916 [inline] #3: ffff888139972198 (&dev->mutex){....}-{4:4}, at: serial_show+0x26/0xa0 drivers/usb/core/sysfs.c:143 3 locks held by kworker/1:6/5455: #0: ffff88810768e548 ((wq_completion)usb_hub_wq){+.+.}-{0:0} , at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc90011e67d10 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffff88810b37f198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #2: ffff88810b37f198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x5060 drivers/usb/core/hub.c:5898 4 locks held by udevd/5634: #0: ffff8881346cb9e0 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x12c0 fs/seq_file.c:182 #1: ffff8881362be088 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172 #2: ffff888133b484b8 (kn->active#23){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888133b484b8 (kn->active#23){++++}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:173 #3: ffff88813989f198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:916 [inline] #3: ffff88813989f198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 4 locks held by udevd/5636: #0: ffff88811db190a0 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x12c0 fs/seq_file.c:182 #1: ffff88811c979888 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172 #2: ffff888112d5e788 (kn->active#23){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888112d5e788 (kn->active#23){++++}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:173 #3: ffff8881231ea198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:916 [inline] #3: ffff8881231ea198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 3 locks held by kworker/u8:0/8517: #0: ffff888111ef5148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0} , at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc90012bdfd10 ((work_completion)(&(&net->ipv6.addr_chk_work)->work) ){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffffffff8a5fc208 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8a5fc208 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x12/0x30 net/ipv6/addrconf.c:4734 6 locks held by kworker/1:1/9514: #0: ffff88810768e548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc90001e9fd10 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffff88810b757198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #2: ffff88810b757198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x5060 drivers/usb/core/hub.c:5898 #3: ffff888139972198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #3: ffff888139972198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1006 #4: ffff8881375a3160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #4: ffff8881375a3160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1006 #5: ffffffff8a5fc208 (rtnl_mutex){+.+.}-{4:4} , at: rtnl_net_lock_killable include/linux/rtnetlink.h:145 [inline] , at: register_netdev+0x18/0x50 net/core/dev.c:11319 6 locks held by kworker/1:8/10683: #0: ffff88810768e548 ((wq_completion)usb_hub_wq){+.+.}-{0:0} , at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc90012b67d10 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffff88810afef198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #2: ffff88810afef198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x5060 drivers/usb/core/hub.c:5898 #3: ffff8881231ea198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #3: ffff8881231ea198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1006 #4: ffff8881072c2160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #4: ffff8881072c2160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1006 #5: ffffffff8a5fc208 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock_killable include/linux/rtnetlink.h:145 [inline] #5: ffffffff8a5fc208 (rtnl_mutex){+.+.}-{4:4}, at: register_netdev+0x18/0x50 net/core/dev.c:11319 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 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] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf0e/0x1260 kernel/hung_task.c:491 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x56d/0x700 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: 23 Comm: kworker/1:0 Not tainted syzkaller #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: events legacy_dvb_usb_read_remote_control RIP: 0010:_prb_read_valid+0x798/0x890 kernel/printk/printk_ringbuffer.c:2151 Code: 90 34 0b 0f 85 fa 00 00 00 48 81 c4 30 01 00 00 89 d8 5b 5d 41 5c 41 5d 41 5e 41 5f e9 81 9e e2 05 4c 8b 64 24 48 31 db eb 9f <4c> 8b 64 24 48 eb 93 48 89 ef e8 09 fd 7d 00 e9 7b fd ff ff bb 01 RSP: 0018:ffffc9000018f4e0 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff815e2d45 RDX: ffff888101ee5700 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 0000000000000053 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: 000000000046d948 R12: ffffffff939cb3e0 R13: 00000000000127a0 R14: ffffffff891d4de0 R15: ffffc9000018f5b0 FS: 0000000000000000(0000) GS:ffff888268ff4000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffdc4a55f08 CR3: 0000000119404000 CR4: 00000000003506f0 Call Trace: prb_read_valid+0x78/0xa0 kernel/printk/printk_ringbuffer.c:2185 printk_get_next_message+0x15b/0x6d0 kernel/printk/printk.c:3005 console_emit_next_record kernel/printk/printk.c:3092 [inline] console_flush_all+0x6ea/0xc60 kernel/printk/printk.c:3226 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline] console_unlock+0xd8/0x210 kernel/printk/printk.c:3325 vprintk_emit+0x418/0x6d0 kernel/printk/printk.c:2450 _printk+0xc7/0x100 kernel/printk/printk.c:2475 legacy_dvb_usb_read_remote_control+0x40b/0x4f0 drivers/media/usb/dvb-usb/dvb-usb-remote.c:124 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x56d/0x700 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245