INFO: task kworker/0:6:6081 blocked for more than 143 seconds. Not tainted 6.13.0-rc7-syzkaller-g70cd0576aa39 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:6 state:D stack:21616 pid:6081 tgid:6081 ppid:2 flags:0x00004000 Workqueue: events console_callback Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x102c/0x34b0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6848 schedule_timeout+0x244/0x280 kernel/time/sleep_timeout.c:75 ___down_common+0x2d7/0x460 kernel/locking/semaphore.c:225 __down_common kernel/locking/semaphore.c:246 [inline] __down+0x20/0x30 kernel/locking/semaphore.c:254 down+0x74/0xa0 kernel/locking/semaphore.c:63 console_lock+0x5b/0xa0 kernel/printk/printk.c:2833 console_callback+0x63/0x4c0 drivers/tty/vt/vt.c:3120 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3317 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Showing all locks held in the system: 7 locks held by kworker/0:1/9: #0: ffff8881066b6548 ( (wq_completion)usb_hub_wq ){+.+.}-{0:0} , at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3211 #1: ffffc9000009fd80 ( (work_completion)(&hub->events) ){+.+.}-{0:0} , at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3212 #2: ffff88810b337190 ( &dev->mutex){....}-{4:4} , at: device_lock include/linux/device.h:1014 [inline] , at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5851 #3: ffff8881277f4190 ( &dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:1014 [inline] , at: usb_disconnect+0x10a/0x920 drivers/usb/core/hub.c:2296 #4: ffff888130bb6160 ( &dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:1014 [inline] , at: __device_driver_lock drivers/base/dd.c:1095 [inline] , at: device_release_driver_internal+0xa4/0x610 drivers/base/dd.c:1293 #5: ffffffff8a19e648 ( rtnl_mutex ){+.+.}-{4:4} , at: unregister_netdev+0x12/0x30 net/core/dev.c:11626 #6: ffffffff88ec81b8 ( rcu_state.exp_mutex ){+.+.}-{4:4} , at: exp_funnel_lock+0x282/0x3b0 kernel/rcu/tree_exp.h:297 1 lock held by khungtaskd/30: #0: ffffffff88ebc880 ( rcu_read_lock){....}-{1:3} , at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] , at: rcu_read_lock include/linux/rcupdate.h:849 [inline] , at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6744 1 lock held by dhcpcd/2883: #0: ffffffff8a19e648 ( rtnl_mutex ){+.+.}-{4:4} , at: rtnl_net_lock include/linux/rtnetlink.h:128 [inline] , at: devinet_ioctl+0x26e/0x1f50 net/ipv4/devinet.c:1129 2 locks held by getty/2903: #0: ffff8881122f50a0 (&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/1:4/5249: 2 locks held by kworker/0:6/6081: #0: ffff888100080948 ( (wq_completion)events ){+.+.}-{0:0} , at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3211 #1: ffffc90013737d80 ( console_work){+.+.}-{0:0} , at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3212 6 locks held by kworker/1:3/9139: 4 locks held by udevd/12950: #0: ffff8881183059e0 (&p->lock ){+.+.}-{4:4} , at: seq_read_iter+0xd8/0x12b0 fs/seq_file.c:182 #1: ffff88813565cc88 ( &of->mutex ){+.+.}-{4:4} , at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff888119897788 (kn->active){++++}-{0:0} , at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff888117013190 ( &dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:1014 [inline] , at: uevent_show+0x188/0x3b0 drivers/base/core.c:2729 7 locks held by kworker/0:4/15937: 3 locks held by kworker/0:10/18170: #0: ffff8881066b6548 ( (wq_completion)usb_hub_wq ){+.+.}-{0:0} , at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3211 #1: ffffc90006e0fd80 ( (work_completion)(&hub->events) ){+.+.}-{0:0} , at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3212 #2: ffff88810b387218 ( &dev->power.lock ){-.-.}-{3:3} , at: lock_timer_base+0x5d/0x220 kernel/time/timer.c:1050 2 locks held by kworker/1:12/18633: 1 lock held by syz.9.3289/19097: #0: ffffffff88ec81b8 ( rcu_state.exp_mutex ){+.+.}-{4:4} , at: exp_funnel_lock+0x1a4/0x3b0 kernel/rcu/tree_exp.h:329 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.13.0-rc7-syzkaller-g70cd0576aa39 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 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:234 [inline] watchdog+0xf14/0x1240 kernel/hung_task.c:397 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 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: 8 Comm: kworker/0:0 Not tainted 6.13.0-rc7-syzkaller-g70cd0576aa39 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Workqueue: usb_hub_wq hub_event RIP: 0010:io_serial_out+0x8f/0xb0 drivers/tty/serial/8250/8250_port.c:416 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 e1 0e 0c ff eb a0 e8 6a 0f 0c RSP: 0018:ffffc9000008f370 EFLAGS: 00000002 RAX: 0000000000000038 RBX: 00000000000003f8 RCX: 0000000000000000 RDX: 00000000000003f8 RSI: ffffffff82a91545 RDI: ffffffff93644920 RBP: ffffffff936448e0 R08: 0000000000000001 R09: 000000000000001f R10: 0000000000000000 R11: 0000000000000009 R12: 0000000000000000 R13: 0000000000000038 R14: ffffffff82a914e0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881f5800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff4e5807bac CR3: 0000000123974000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: serial_out drivers/tty/serial/8250/8250.h:142 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3342 [inline] serial8250_console_write+0xf9e/0x17c0 drivers/tty/serial/8250/8250_port.c:3413 console_emit_next_record kernel/printk/printk.c:3122 [inline] console_flush_all+0x800/0xc60 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 dev_vprintk_emit drivers/base/core.c:4935 [inline] dev_printk_emit+0xfb/0x140 drivers/base/core.c:4946 __dev_printk+0xf5/0x270 drivers/base/core.c:4958 _dev_info+0xe5/0x120 drivers/base/core.c:5004 hub_port_init+0xce6/0x3ab0 drivers/usb/core/hub.c:4952 hub_port_connect drivers/usb/core/hub.c:5452 [inline] hub_port_connect_change drivers/usb/core/hub.c:5663 [inline] port_event drivers/usb/core/hub.c:5823 [inline] hub_event+0x2c16/0x4f40 drivers/usb/core/hub.c:5905 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3317 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244