INFO: task syz-executor.2:6934 blocked for more than 143 seconds. Not tainted 5.7.0-rc6-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D28848 6934 378 0x80004006 Call Trace: context_switch kernel/sched/core.c:3367 [inline] __schedule+0x892/0x1d80 kernel/sched/core.c:4083 locks_remove_posix+0x277/0x4e0 fs/locks.c:2706 __sched_text_start+0x8/0x8 spin_unlock_irqrestore include/linux/spinlock.h:408 [inline] prepare_to_wait_event+0x129/0x650 kernel/sched/wait.c:305 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] _raw_spin_unlock_irqrestore+0x39/0x40 kernel/locking/spinlock.c:191 schedule+0xcd/0x2b0 kernel/sched/core.c:4158 wdm_flush+0x2ea/0x3c0 drivers/usb/class/cdc-wdm.c:590 wdm_poll+0x280/0x280 include/linux/poll.h:50 finish_wait+0x260/0x260 include/linux/list.h:301 task_work_add+0x97/0x120 kernel/task_work.c:35 wdm_poll+0x280/0x280 include/linux/poll.h:50 filp_close+0xb4/0x170 fs/open.c:1251 close_files fs/file.c:388 [inline] put_files_struct fs/file.c:416 [inline] put_files_struct+0x1d8/0x2e0 fs/file.c:413 exit_files+0x7e/0xa0 fs/file.c:445 do_exit+0xb36/0x2c80 kernel/exit.c:791 find_held_lock+0x2d/0x110 kernel/locking/lockdep.c:4458 mm_update_next_owner+0x7a0/0x7a0 kernel/exit.c:375 lock_downgrade+0x720/0x720 kernel/locking/lockdep.c:4599 do_group_exit+0x125/0x340 kernel/exit.c:894 get_signal+0x480/0x2480 kernel/signal.c:2739 down_interruptible+0x4b/0x80 kernel/locking/semaphore.c:85 do_signal+0x88/0x1ae0 arch/x86/kernel/signal.c:784 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] _raw_spin_unlock_irqrestore+0x39/0x40 kernel/locking/spinlock.c:191 __trace_hardirqs_on_caller kernel/locking/lockdep.c:3657 [inline] lockdep_hardirqs_on+0x3c7/0x5d0 kernel/locking/lockdep.c:3702 force_valid_ss arch/x86/kernel/signal.c:73 [inline] restore_sigcontext+0x620/0x620 arch/x86/kernel/signal.c:134 down_interruptible+0x4b/0x80 kernel/locking/semaphore.c:85 raw_ioctl+0x11f/0x2570 drivers/usb/gadget/legacy/raw_gadget.c:1261 ksys_dup3+0x3c0/0x3c0 include/linux/compiler.h:199 task_work_add+0x97/0x120 kernel/task_work.c:35 exit_to_usermode_loop+0x1a2/0x200 arch/x86/entry/common.c:161 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] syscall_return_slowpath arch/x86/entry/common.c:279 [inline] do_syscall_64+0x4e0/0x5a0 arch/x86/entry/common.c:305 entry_SYSCALL_64_after_hwframe+0x49/0xb3 INFO: task syz-executor.1:6897 blocked for more than 143 seconds. Not tainted 5.7.0-rc6-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28552 6897 396 0x80004006 Call Trace: context_switch kernel/sched/core.c:3367 [inline] __schedule+0x892/0x1d80 kernel/sched/core.c:4083 locks_remove_posix+0x277/0x4e0 fs/locks.c:2706 __sched_text_start+0x8/0x8 spin_unlock_irqrestore include/linux/spinlock.h:408 [inline] prepare_to_wait_event+0x129/0x650 kernel/sched/wait.c:305 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] _raw_spin_unlock_irqrestore+0x39/0x40 kernel/locking/spinlock.c:191 schedule+0xcd/0x2b0 kernel/sched/core.c:4158 wdm_flush+0x2ea/0x3c0 drivers/usb/class/cdc-wdm.c:590 wdm_poll+0x280/0x280 include/linux/poll.h:50 finish_wait+0x260/0x260 include/linux/list.h:301 task_work_add+0x97/0x120 kernel/task_work.c:35 wdm_poll+0x280/0x280 include/linux/poll.h:50 filp_close+0xb4/0x170 fs/open.c:1251 close_files fs/file.c:388 [inline] put_files_struct fs/file.c:416 [inline] put_files_struct+0x1d8/0x2e0 fs/file.c:413 exit_files+0x7e/0xa0 fs/file.c:445 do_exit+0xb36/0x2c80 kernel/exit.c:791 find_held_lock+0x2d/0x110 kernel/locking/lockdep.c:4458 mm_update_next_owner+0x7a0/0x7a0 kernel/exit.c:375 lock_downgrade+0x720/0x720 kernel/locking/lockdep.c:4599 do_group_exit+0x125/0x340 kernel/exit.c:894 get_signal+0x480/0x2480 kernel/signal.c:2739 schedule_timeout_idle+0x80/0x80 kernel/time/timer.c:1942 do_signal+0x88/0x1ae0 arch/x86/kernel/signal.c:784 free_object+0x5/0x70 lib/debugobjects.c:429 destroy_hrtimer_on_stack kernel/time/hrtimer.c:453 [inline] hrtimer_nanosleep+0x211/0x3a0 kernel/time/hrtimer.c:1947 nanosleep_copyout+0x100/0x100 kernel/time/hrtimer.c:1861 force_valid_ss arch/x86/kernel/signal.c:73 [inline] restore_sigcontext+0x620/0x620 arch/x86/kernel/signal.c:134 hrtimer_init_sleeper_on_stack+0x90/0x90 kernel/time/hrtimer.c:1833 put_old_itimerspec32+0x1d0/0x1d0 kernel/time/time.c:908 __do_sys_nanosleep kernel/time/hrtimer.c:1962 [inline] __se_sys_nanosleep kernel/time/hrtimer.c:1953 [inline] __x64_sys_nanosleep+0x1ed/0x260 kernel/time/hrtimer.c:1953 hrtimer_nanosleep+0x3a0/0x3a0 kernel/time/hrtimer.c:1943 exit_to_usermode_loop+0x1a2/0x200 arch/x86/entry/common.c:161 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] syscall_return_slowpath arch/x86/entry/common.c:279 [inline] do_syscall_64+0x4e0/0x5a0 arch/x86/entry/common.c:305 entry_SYSCALL_64_after_hwframe+0x49/0xb3 INFO: task syz-executor.4:6927 blocked for more than 143 seconds. Not tainted 5.7.0-rc6-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D28552 6927 380 0x00000004 Call Trace: context_switch kernel/sched/core.c:3367 [inline] __schedule+0x892/0x1d80 kernel/sched/core.c:4083 __sched_text_start+0x8/0x8 spin_unlock_irqrestore include/linux/spinlock.h:408 [inline] prepare_to_wait_event+0x129/0x650 kernel/sched/wait.c:305 schedule+0xcd/0x2b0 kernel/sched/core.c:4158 wdm_flush+0x2ea/0x3c0 drivers/usb/class/cdc-wdm.c:590 wdm_poll+0x280/0x280 include/linux/poll.h:50 finish_wait+0x260/0x260 include/linux/list.h:301 wdm_poll+0x280/0x280 include/linux/poll.h:50 filp_close+0xb4/0x170 fs/open.c:1251 __close_fd+0x133/0x200 fs/file.c:641 __do_sys_close fs/open.c:1270 [inline] __se_sys_close fs/open.c:1268 [inline] __x64_sys_close+0x69/0x100 fs/open.c:1268 __trace_hardirqs_on_caller kernel/locking/lockdep.c:3657 [inline] lockdep_hardirqs_on+0x3c7/0x5d0 kernel/locking/lockdep.c:3702 do_syscall_64+0xb6/0x5a0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 get_current arch/x86/include/asm/current.h:15 [inline] __fpregs_load_activate arch/x86/include/asm/fpu/internal.h:536 [inline] switch_fpu_return+0x68/0x470 arch/x86/kernel/fpu/core.c:343 entry_SYSCALL_64_after_hwframe+0x49/0xb3 INFO: task syz-executor.0:6937 blocked for more than 143 seconds. Not tainted 5.7.0-rc6-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28552 6937 377 0x00000004 Call Trace: context_switch kernel/sched/core.c:3367 [inline] __schedule+0x892/0x1d80 kernel/sched/core.c:4083 __sched_text_start+0x8/0x8 spin_unlock_irqrestore include/linux/spinlock.h:408 [inline] prepare_to_wait_event+0x129/0x650 kernel/sched/wait.c:305 schedule+0xcd/0x2b0 kernel/sched/core.c:4158 wdm_flush+0x2ea/0x3c0 drivers/usb/class/cdc-wdm.c:590 wdm_poll+0x280/0x280 include/linux/poll.h:50 finish_wait+0x260/0x260 include/linux/list.h:301 wdm_poll+0x280/0x280 include/linux/poll.h:50 filp_close+0xb4/0x170 fs/open.c:1251 __close_fd+0x133/0x200 fs/file.c:641 __do_sys_close fs/open.c:1270 [inline] __se_sys_close fs/open.c:1268 [inline] __x64_sys_close+0x69/0x100 fs/open.c:1268 __trace_hardirqs_on_caller kernel/locking/lockdep.c:3657 [inline] lockdep_hardirqs_on+0x3c7/0x5d0 kernel/locking/lockdep.c:3702 do_syscall_64+0xb6/0x5a0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 Showing all locks held in the system: 1 lock held by khungtaskd/23: #0: ffffffff87111260 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x264 kernel/locking/lockdep.c:5754 2 locks held by agetty/274: #0: ffff8881d2659098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc90000a122e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x220/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by agetty/275: #0: ffff8881d2022098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc90000a262e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x220/0x1b30 drivers/tty/n_tty.c:2156 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 23 Comm: khungtaskd Not tainted 5.7.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0xef/0x16e lib/dump_stack.c:118 irq_force_complete_move.cold+0x13/0x47 arch/x86/kernel/apic/vector.c:1023 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 lapic_can_unplug_cpu.cold+0x3b/0x3b nmi_trigger_cpumask_backtrace+0x1db/0x207 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xa99/0xfd0 kernel/hung_task.c:289 reset_hung_task_detector+0x30/0x30 kernel/hung_task.c:243 kthread+0x326/0x430 kernel/kthread.c:268 kthread_create_on_node+0xf0/0xf0 kernel/kthread.c:405 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:351 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 10 Comm: rcu_sched Not tainted 5.7.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:debug_object_is_on_stack lib/debugobjects.c:517 [inline] RIP: 0010:__debug_object_init+0x4d3/0xde0 lib/debugobjects.c:582 Code: 48 c1 ea 03 80 3c 02 00 0f 85 a6 05 00 00 48 8b 45 18 49 39 c4 0f 82 bb 03 00 00 48 05 00 80 00 00 49 39 c4 0f 83 ac 03 00 00 <83> 7c 24 68 01 0f 84 90 fc ff ff e9 09 1c 00 00 83 f8 04 0f 85 a4 RSP: 0018:ffff8881da207b60 EFLAGS: 00000287 RAX: ffff8881da208000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 1ffff1103b43bc63 RSI: 0000000000000006 RDI: ffff8881da1de318 RBP: ffff8881da1de300 R08: ffff8881da1de300 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8881da207cf0 R13: 0000000000000000 R14: ffffffff8979ea50 R15: ffff8881cfc06188 FS: 0000000000000000(0000) GS:ffff8881db300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f60923d8000 CR3: 00000001d181a000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: mark_held_locks+0xe0/0xe0 kernel/locking/lockdep.c:3620 fill_pool+0x5d0/0x5d0 lib/debugobjects.c:185 mark_held_locks+0xe0/0xe0 kernel/locking/lockdep.c:3620 debug_object_fixup+0x30/0x30 lib/debugobjects.c:506 find_held_lock+0x2d/0x110 kernel/locking/lockdep.c:4458 __next_timer_interrupt+0x190/0x190 kernel/time/timer.c:1512 init_timer_on_stack_key+0x2b/0xe0 kernel/time/timer.c:742 schedule_timeout+0x110/0x7d0 kernel/time/timer.c:1896 usleep_range+0x160/0x160 kernel/time/timer.c:2093 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] _raw_spin_unlock_irqrestore+0x39/0x40 kernel/locking/spinlock.c:191 __trace_hardirqs_on_caller kernel/locking/lockdep.c:3657 [inline] lockdep_hardirqs_on+0x3c7/0x5d0 kernel/locking/lockdep.c:3702 prepare_to_swait_event+0x107/0x330 kernel/sched/swait.c:120 prepare_to_swait_exclusive+0x110/0x110 kernel/sched/swait.c:98 rcu_read_lock_bh_held+0xb0/0xb0 kernel/rcu/update.c:333 rcu_gp_fqs_loop kernel/rcu/tree.c:1674 [inline] rcu_gp_kthread+0xac6/0x1cb0 kernel/rcu/tree.c:1836 call_rcu+0xa90/0xa90 include/linux/compiler.h:199 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] _raw_spin_unlock_irqrestore+0x39/0x40 kernel/locking/spinlock.c:191 __trace_hardirqs_on_caller kernel/locking/lockdep.c:3657 [inline] lockdep_hardirqs_on+0x3c7/0x5d0 kernel/locking/lockdep.c:3702 __kthread_parkme+0x118/0x1d0 kernel/kthread.c:212 call_rcu+0xa90/0xa90 include/linux/compiler.h:199 kthread+0x326/0x430 kernel/kthread.c:268 kthread_create_on_node+0xf0/0xf0 kernel/kthread.c:405 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:351