INFO: task kworker/1:3:5228 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/1:3 state:D stack:21008 pid:5228 tgid:5228 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: 1 lock held by khungtaskd/30: #0: ffffffff88ebc880 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff88ebc880 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff88ebc880 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6744 6 locks held by kworker/0:2/1120: #0: ffff888106687548 ((wq_completion)usb_hub_wq){+.+.}-{0:0} , at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3211 #1: ffffc9000205fd80 ((work_completion)(&hub->events) ){+.+.}-{0:0} , at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3212 #2: ffff88810afb6190 ( &dev->mutex ){....}-{4:4}, at: device_lock include/linux/device.h:1014 [inline] ){....}-{4:4}, at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5851 #3: ffff88810b3a9508 ( &port_dev->status_lock ){+.+.}-{4:4} , at: usb_lock_port drivers/usb/core/hub.c:3209 [inline] , at: hub_port_connect drivers/usb/core/hub.c:5420 [inline] , at: hub_port_connect_change drivers/usb/core/hub.c:5663 [inline] , at: port_event drivers/usb/core/hub.c:5823 [inline] , at: hub_event+0x28aa/0x4f40 drivers/usb/core/hub.c:5905 #4: ffff88810975d968 (hcd->address0_mutex ){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5421 [inline] ){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5663 [inline] ){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5823 [inline] ){+.+.}-{4:4}, at: hub_event+0x28d0/0x4f40 drivers/usb/core/hub.c:5905 #5: ffff8881f583d318 (&rq->__lock ){-.-.}-{2:2} , at: hub_port_reset+0x1a7/0x1e60 drivers/usb/core/hub.c:3024 2 locks held by getty/2905: #0: ffff888100ead0a0 (&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 4 locks held by udevd/5205: #0: ffff8881013dee80 (&p->lock ){+.+.}-{4:4} , at: seq_read_iter+0xd8/0x12b0 fs/seq_file.c:182 #1: ffff888137c65888 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff888107b81878 (kn->active#3){++++}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff88810afb6190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1014 [inline] #3: ffff88810afb6190 (&dev->mutex){....}-{4:4}, at: uevent_show+0x188/0x3b0 drivers/base/core.c:2729 4 locks held by udevd/5216: #0: ffff88813b7f7540 (&p->lock ){+.+.}-{4:4}, at: seq_read_iter+0xd8/0x12b0 fs/seq_file.c:182 #1: ffff888135257088 (&of->mutex #2){+.+.}-{4:4}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff888107b81878 (kn->active#3){++++}-{0:0} , at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff88810afb6190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1014 [inline] (&dev->mutex){....}-{4:4}, at: uevent_show+0x188/0x3b0 drivers/base/core.c:2729 2 locks held by kworker/1:3/5228: #0: ffff888100080948 ((wq_completion)events ){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3211 #1: ffffc900020ffd80 (console_work ){+.+.}-{0:0} , at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3212 3 locks held by kworker/0:5/5258: #0: ffff888106687548 ( (wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3211 #1: ffffc90002247d80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3212 #2: ffff88810b3ae190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1014 [inline] (&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5851 5 locks held by kworker/1:7/7212: 6 locks held by kworker/1:11/19683: 2 locks held by syz.4.4157/21833: ============================================= 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: 5596 Comm: kworker/0:6 Not tainted 6.13.0-rc7-syzkaller-g70cd0576aa39 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Workqueue: events legacy_dvb_usb_read_remote_control RIP: 0010:io_serial_in+0x87/0xb0 drivers/tty/serial/8250/8250_port.c:410 Code: 54 b2 fe 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 1a 66 03 5d 40 89 da ec <5b> 0f b6 c0 5d 41 5c c3 cc cc cc cc e8 28 0e 0c ff eb a2 e8 b1 0e RSP: 0018:ffffc90005117770 EFLAGS: 00000006 RAX: dffffc0000000005 RBX: 00000000000003f9 RCX: 0000000000000000 RDX: 00000000000003f9 RSI: ffffffff82a91600 RDI: ffffffff93644920 RBP: ffffffff936448e0 R08: 0000000000000001 R09: 000000000000001f R10: 0000000000000000 R11: 0000000000000006 R12: 0000000000000000 R13: ffffffff936448e0 R14: ffffffff93644930 R15: 000000000000002f FS: 0000000000000000(0000) GS:ffff8881f5800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9ce9470160 CR3: 0000000126bbc000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: serial_port_in include/linux/serial_core.h:791 [inline] serial8250_console_write+0x22d/0x17c0 drivers/tty/serial/8250/8250_port.c:3377 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 vprintk+0x7f/0xa0 kernel/printk/printk_safe.c:86 _printk+0xc8/0x100 kernel/printk/printk.c:2457 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: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