INFO: task kworker/u4:5:1108 blocked for more than 143 seconds. Not tainted 6.4.0-rc1-syzkaller-00026-g80e62bc8487b #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:5 state:D stack:26360 pid:1108 ppid:2 flags:0x00004000 Workqueue: events_unbound io_ring_exit_work Call Trace: context_switch kernel/sched/core.c:5343 [inline] __schedule+0xc9a/0x5880 kernel/sched/core.c:6669 schedule+0xde/0x1a0 kernel/sched/core.c:6745 schedule_timeout+0x276/0x2b0 kernel/time/timer.c:2143 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common+0x1ce/0x5c0 kernel/sched/completion.c:106 io_ring_exit_work+0x51d/0x14b0 io_uring/io_uring.c:3077 process_one_work+0x99a/0x15e0 kernel/workqueue.c:2405 worker_thread+0x67d/0x10c0 kernel/workqueue.c:2552 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 INFO: task syz-executor.1:24538 blocked for more than 144 seconds. Not tainted 6.4.0-rc1-syzkaller-00026-g80e62bc8487b #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.1 state:D stack:25336 pid:24538 ppid:5053 flags:0x00024004 Call Trace: context_switch kernel/sched/core.c:5343 [inline] __schedule+0xc9a/0x5880 kernel/sched/core.c:6669 schedule+0xde/0x1a0 kernel/sched/core.c:6745 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6804 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0xa3b/0x1350 kernel/locking/mutex.c:747 device_lock include/linux/device.h:837 [inline] usbdev_open+0x1a1/0x990 drivers/usb/core/devio.c:1041 chrdev_open+0x26a/0x770 fs/char_dev.c:414 do_dentry_open+0x6cc/0x13f0 fs/open.c:920 do_open fs/namei.c:3636 [inline] path_openat+0x1baa/0x2750 fs/namei.c:3791 do_filp_open+0x1ba/0x410 fs/namei.c:3818 do_sys_openat2+0x16d/0x4c0 fs/open.c:1356 do_sys_open fs/open.c:1372 [inline] __do_sys_openat fs/open.c:1388 [inline] __se_sys_openat fs/open.c:1383 [inline] __x64_sys_openat+0x143/0x1f0 fs/open.c:1383 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f88b3e3e2f4 RSP: 002b:00007f88b4c9dca0 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 6666666666666667 RCX: 00007f88b3e3e2f4 RDX: 0000000000101301 RSI: 00007f88b4c9dd40 RDI: 00000000ffffff9c RBP: 00007f88b4c9dd40 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000101301 R13: 00007f88b40cfb1f R14: 00007f88b4c9e300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/13: #0: ffffffff8c798430 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x31/0xd80 kernel/rcu/tasks.h:518 1 lock held by rcu_tasks_trace/14: #0: ffffffff8c798130 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x31/0xd80 kernel/rcu/tasks.h:518 1 lock held by khungtaskd/28: #0: ffffffff8c799040 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x340 kernel/locking/lockdep.c:6545 1 lock held by kworker/0:1H/52: #0: ffff8880b983c5d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:566 [inline] #0: ffff8880b983c5d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x90/0x120 kernel/sched/core.c:551 2 locks held by kworker/u4:4/63: 2 locks held by kworker/u4:5/1108: #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1324 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:643 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:670 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x883/0x15e0 kernel/workqueue.c:2376 #1: ffffc90005607db0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x8b7/0x15e0 kernel/workqueue.c:2380 2 locks held by getty/4753: #0: ffff8880287d4098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x26/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900015802f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xef4/0x13e0 drivers/tty/n_tty.c:2176 1 lock held by syz-executor.3/5050: 6 locks held by kworker/0:3/5092: 2 locks held by kworker/u4:18/9064: #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1324 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:643 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:670 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x883/0x15e0 kernel/workqueue.c:2376 #1: ffffc90006917db0 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x8b7/0x15e0 kernel/workqueue.c:2380 2 locks held by kworker/u4:19/9066: #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1324 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:643 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:670 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x883/0x15e0 kernel/workqueue.c:2376 #1: ffffc90006937db0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x8b7/0x15e0 kernel/workqueue.c:2380 1 lock held by syz-executor.1/24538: #0: ffff888022a28190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline] #0: ffff888022a28190 (&dev->mutex){....}-{3:3}, at: usbdev_open+0x1a1/0x990 drivers/usb/core/devio.c:1041 2 locks held by kworker/u4:1/25173: #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1324 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:643 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:670 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x883/0x15e0 kernel/workqueue.c:2376 #1: ffffc90018007db0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x8b7/0x15e0 kernel/workqueue.c:2380 2 locks held by kworker/u4:7/27502: #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1324 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:643 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:670 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x883/0x15e0 kernel/workqueue.c:2376 #1: ffffc900157a7db0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x8b7/0x15e0 kernel/workqueue.c:2380 1 lock held by syz-executor.2/27543: 1 lock held by syz-executor.1/27562: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.4.0-rc1-syzkaller-00026-g80e62bc8487b #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106 nmi_cpu_backtrace+0x29c/0x350 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x2a4/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xe16/0x1090 kernel/hung_task.c:379 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:86 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt+0x40/0x50 drivers/acpi/processor_idle.c:112