INFO: task kworker/1:7:12818 blocked for more than 143 seconds. Not tainted 6.12.0-rc6-syzkaller-00153-g237d4e0f4113 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:7 state:D stack:22112 pid:12818 tgid:12818 ppid:2 flags:0x00004000 Workqueue: events console_callback Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0x1042/0x34b0 kernel/sched/core.c:6690 __schedule_loop kernel/sched/core.c:6767 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6782 schedule_timeout+0x258/0x2a0 kernel/time/timer.c:2591 ___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:2808 console_callback+0x63/0x4c0 drivers/tty/vt/vt.c:3120 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 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: 6 locks held by kworker/0:0/8: 1 lock held by khungtaskd/30: #0: ffffffff88ebb140 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff88ebb140 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff88ebb140 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6720 3 locks held by kworker/0:2/1114: 2 locks held by getty/2919: #0: ffff88811218d0a0 (&tty->ldisc_sem){++++}-{0:0} , at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900000432f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211 3 locks held by kworker/1:2/2923: #0: ffff888100080948 ((wq_completion)events ){+.+.}-{0:0}, at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc900019efd80 ( free_ipc_work ){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 #2: ffffffff88ec6a38 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock+0x282/0x3b0 kernel/rcu/tree_exp.h:297 1 lock held by udevd/5218: #0: ffff888100abc148 (&root->kernfs_rwsem){++++}-{3:3} , at: kernfs_dop_revalidate+0xf0/0x5a0 fs/kernfs/dir.c:1159 4 locks held by kworker/1:3/5243: #0: ffff888106aa0148 ( (wq_completion)usb_hub_wq ){+.+.}-{0:0}, at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc900021bfd80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 #2: ffff88810a7ff190 (&dev->mutex){....}-{3:3} , at: device_lock include/linux/device.h:1014 [inline] , at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5849 #3: ffff888100abc148 (&root->kernfs_rwsem){++++}-{3:3}, at: kernfs_add_one+0xb1/0x520 fs/kernfs/dir.c:778 1 lock held by udevd/5499: #0: ffff888100abc148 (&root->kernfs_rwsem){++++}-{3:3} , at: kernfs_dop_revalidate+0xf0/0x5a0 fs/kernfs/dir.c:1159 4 locks held by kworker/0:6/5610: #0: ffff888106aa0148 ( (wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc90002eb7d80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 #2: ffff88810a7fa190 ( &dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] &dev->mutex){....}-{3:3}, at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5849 #3: ffff888100abc148 (&root->kernfs_rwsem){++++}-{3:3}, at: kernfs_add_one+0xb1/0x520 fs/kernfs/dir.c:778 4 locks held by kworker/u8:2/12674: #0: ffff888100abb148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc90002417d80 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 #2: ffffffff8a1872d0 (pernet_ops_rwsem ){++++}-{3:3} , at: cleanup_net+0xbb/0xb40 net/core/net_namespace.c:580 #3: ffffffff88ec6a38 (rcu_state.exp_mutex ){+.+.}-{3:3} , at: exp_funnel_lock+0x1a4/0x3b0 kernel/rcu/tree_exp.h:329 2 locks held by kworker/1:7/12818: #0: ffff888100080948 ((wq_completion)events ){+.+.}-{0:0} , at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc9000202fd80 (console_work ){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 1 lock held by syz-executor/15132: #0: ffff888100abc148 ( &root->kernfs_rwsem){++++}-{3:3}, at: kernfs_dop_revalidate+0xf0/0x5a0 fs/kernfs/dir.c:1159 1 lock held by syz-executor/15738: #0: ffff888100abc148 ( &root->kernfs_rwsem){++++}-{3:3} , at: kernfs_dop_revalidate+0xf0/0x5a0 fs/kernfs/dir.c:1159 1 lock held by syz-executor/16856: #0: ffff888100abc148 (&root->kernfs_rwsem){++++}-{3:3} , at: kernfs_dop_revalidate+0xf0/0x5a0 fs/kernfs/dir.c:1159 1 lock held by syz-executor/17475: #0: ffff888100abc148 ( &root->kernfs_rwsem){++++}-{3:3}, at: kernfs_dop_revalidate+0xf0/0x5a0 fs/kernfs/dir.c:1159 2 locks held by kworker/0:8/18327: 1 lock held by syz.4.4284/22139: 1 lock held by syz.2.4292/22188: #0: ffff888100abc148 (&root->kernfs_rwsem){++++}-{3:3} , at: kernfs_remove_by_name_ns+0x87/0x130 fs/kernfs/dir.c:1689 1 lock held by syz.0.4293/22174: #0: ffff888100abc148 (&root->kernfs_rwsem ){++++}-{3:3} , at: kernfs_remove_by_name_ns+0x87/0x130 fs/kernfs/dir.c:1689 1 lock held by syz.1.4295/22185: #0: ffff888100abc148 (&root->kernfs_rwsem){++++}-{3:3} , at: kernfs_add_one+0xb1/0x520 fs/kernfs/dir.c:778 1 lock held by sed/22191: #0: ffff888100abc148 (&root->kernfs_rwsem){++++}-{3:3} , at: kernfs_dop_revalidate+0xf0/0x5a0 fs/kernfs/dir.c:1159 1 lock held by syz.3.4296/22193: #0: ffff888100abc148 ( &root->kernfs_rwsem){++++}-{3:3} , at: kernfs_add_one+0xb1/0x520 fs/kernfs/dir.c:778 1 lock held by syz-executor/22194: #0: ffff888100abc148 (&root->kernfs_rwsem ){++++}-{3:3} , at: kernfs_dop_revalidate+0xf0/0x5a0 fs/kernfs/dir.c:1159 1 lock held by syz-executor/22195: #0: ffff888100abc148 (&root->kernfs_rwsem){++++}-{3:3} , at: kernfs_dop_revalidate+0xf0/0x5a0 fs/kernfs/dir.c:1159 1 lock held by syz-executor/22196: #0: ffff888100abc148 (&root->kernfs_rwsem){++++}-{3:3} , at: kernfs_dop_revalidate+0xf0/0x5a0 fs/kernfs/dir.c:1159 1 lock held by syz-executor/22197: #0: ffff888100abc148 (&root->kernfs_rwsem){++++}-{3:3} , at: kernfs_dop_revalidate+0xf0/0x5a0 fs/kernfs/dir.c:1159 1 lock held by syz-executor/22198: #0: ffff888100abc148 ( &root->kernfs_rwsem ){++++}-{3:3}, at: kernfs_dop_revalidate+0xf0/0x5a0 fs/kernfs/dir.c:1159 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc6-syzkaller-00153-g237d4e0f4113 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 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:223 [inline] watchdog+0xf0c/0x1240 kernel/hung_task.c:379 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: yealink 1-1:36.0: urb_ctl_callback - urb status -71 NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 18327 Comm: kworker/0:8 Not tainted 6.12.0-rc6-syzkaller-00153-g237d4e0f4113 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events legacy_dvb_usb_read_remote_control RIP: 0010:io_serial_out+0x8f/0xb0 drivers/tty/serial/8250/8250_port.c:413 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 11 e5 0d ff eb a0 e8 9a e5 0d RSP: 0018:ffffc900000074e0 EFLAGS: 00000006 RAX: 0000000000000000 RBX: 00000000000003f9 RCX: 0000000000000000 RDX: 00000000000003f9 RSI: ffffffff82a096d5 RDI: ffffffff936336a0 RBP: ffffffff93633660 R08: 0000000000000001 R09: 000000000000001f R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff936336b0 R15: 000000000000003f FS: 0000000000000000(0000) GS:ffff8881f5800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020002100 CR3: 0000000116456000 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_clear_IER+0x9b/0xc0 drivers/tty/serial/8250/8250_port.c:699 serial8250_console_write+0x243/0x17c0 drivers/tty/serial/8250/8250_port.c:3358 console_emit_next_record kernel/printk/printk.c:3092 [inline] console_flush_all+0x800/0xc60 kernel/printk/printk.c:3180 __console_flush_and_unlock kernel/printk/printk.c:3239 [inline] console_unlock+0xd9/0x210 kernel/printk/printk.c:3279 vprintk_emit+0x424/0x6f0 kernel/printk/printk.c:2407 dev_vprintk_emit drivers/base/core.c:4942 [inline] dev_printk_emit+0xfb/0x140 drivers/base/core.c:4953 __dev_printk+0xf5/0x270 drivers/base/core.c:4965 _dev_err+0xe5/0x120 drivers/base/core.c:5008 urb_ctl_callback+0x1eb/0x2f0 drivers/input/misc/yealink.c:456 __usb_hcd_giveback_urb+0x389/0x6e0 drivers/usb/core/hcd.c:1650 usb_hcd_giveback_urb+0x396/0x450 drivers/usb/core/hcd.c:1734 dummy_timer+0x17f0/0x3930 drivers/usb/gadget/udc/dummy_hcd.c:1993 __run_hrtimer kernel/time/hrtimer.c:1691 [inline] __hrtimer_run_queues+0x20a/0xae0 kernel/time/hrtimer.c:1755 hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1772 handle_softirqs+0x206/0x8d0 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu kernel/softirq.c:637 [inline] irq_exit_rcu+0xac/0x110 kernel/softirq.c:649 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0x90/0xb0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:console_flush_all+0x9a4/0xc60 kernel/printk/printk.c:3181 Code: 00 e8 60 4b 27 00 9c 5b 81 e3 00 02 00 00 31 ff 48 89 de e8 be aa 1f 00 48 85 db 0f 85 55 01 00 00 e8 40 a8 1f 00 fb 4c 89 e0 <48> c1 e8 03 42 80 3c 38 00 0f 84 11 ff ff ff 4c 89 e7 e8 c5 31 78 RSP: 0018:ffffc900024ef8b0 EFLAGS: 00000293 RAX: ffffffff8939d958 RBX: 0000000000000000 RCX: ffffffff81364ac2 RDX: ffff88811f510000 RSI: ffffffff81364ad0 RDI: 0000000000000007 RBP: 0000000000000001 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff8939d958 R13: ffffffff8939d900 R14: ffffc900024ef940 R15: dffffc0000000000 __console_flush_and_unlock kernel/printk/printk.c:3239 [inline] console_unlock+0xd9/0x210 kernel/printk/printk.c:3279 vprintk_emit+0x424/0x6f0 kernel/printk/printk.c:2407 vprintk+0x7f/0xa0 kernel/printk/printk_safe.c:68 _printk+0xc8/0x100 kernel/printk/printk.c:2432 legacy_dvb_usb_read_remote_control+0x40d/0x500 drivers/media/usb/dvb-usb/dvb-usb-remote.c:124 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 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