INFO: task syz-executor.4:5657 blocked for more than 143 seconds. Not tainted 6.2.0-rc1-syzkaller-00084-gc8451c141e07 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.4 state:D stack:27752 pid:5657 ppid:5533 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0xb8a/0x5450 kernel/sched/core.c:6555 schedule+0xde/0x1b0 kernel/sched/core.c:6631 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6690 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0xa48/0x1360 kernel/locking/mutex.c:747 tty_open_by_driver drivers/tty/tty_io.c:2043 [inline] tty_open+0x59c/0xfb0 drivers/tty/tty_io.c:2126 chrdev_open+0x26a/0x770 fs/char_dev.c:414 do_dentry_open+0x6cc/0x13f0 fs/open.c:882 do_open fs/namei.c:3557 [inline] path_openat+0x1bbc/0x2a50 fs/namei.c:3714 do_filp_open+0x1ba/0x410 fs/namei.c:3741 do_sys_openat2+0x16d/0x4c0 fs/open.c:1310 do_sys_open fs/open.c:1326 [inline] __do_sys_openat fs/open.c:1342 [inline] __se_sys_openat fs/open.c:1337 [inline] __x64_sys_openat+0x143/0x1f0 fs/open.c:1337 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: 0033:0x7f367423bf74 RSP: 002b:00007f3675436ca0 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f367439bf60 RCX: 00007f367423bf74 RDX: 0000000000000002 RSI: 00007f3675436d40 RDI: 00000000ffffff9c RBP: 00007f3675436d40 R08: 0000000000000000 R09: 000000000000000e R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000002 R13: 00007ffca3604fff R14: 00007f3675437300 R15: 0000000000022000 INFO: task syz-executor.2:5662 blocked for more than 143 seconds. Not tainted 6.2.0-rc1-syzkaller-00084-gc8451c141e07 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.2 state:D stack:27992 pid:5662 ppid:5537 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0xb8a/0x5450 kernel/sched/core.c:6555 schedule+0xde/0x1b0 kernel/sched/core.c:6631 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6690 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0xa48/0x1360 kernel/locking/mutex.c:747 tty_open_by_driver drivers/tty/tty_io.c:2043 [inline] tty_open+0x59c/0xfb0 drivers/tty/tty_io.c:2126 chrdev_open+0x26a/0x770 fs/char_dev.c:414 do_dentry_open+0x6cc/0x13f0 fs/open.c:882 do_open fs/namei.c:3557 [inline] path_openat+0x1bbc/0x2a50 fs/namei.c:3714 do_filp_open+0x1ba/0x410 fs/namei.c:3741 do_sys_openat2+0x16d/0x4c0 fs/open.c:1310 do_sys_open fs/open.c:1326 [inline] __do_sys_openat fs/open.c:1342 [inline] __se_sys_openat fs/open.c:1337 [inline] __x64_sys_openat+0x143/0x1f0 fs/open.c:1337 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: 0033:0x7f0e0ce3bf74 RSP: 002b:00007f0e0e087ca0 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f0e0cf9bf60 RCX: 00007f0e0ce3bf74 RDX: 0000000000000002 RSI: 00007f0e0e087d40 RDI: 00000000ffffff9c RBP: 00007f0e0e087d40 R08: 0000000000000000 R09: 000000000000000e R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000002 R13: 00007ffd9fc7853f R14: 00007f0e0e088300 R15: 0000000000022000 INFO: task syz-executor.0:5661 blocked for more than 143 seconds. Not tainted 6.2.0-rc1-syzkaller-00084-gc8451c141e07 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:27992 pid:5661 ppid:5536 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0xb8a/0x5450 kernel/sched/core.c:6555 schedule+0xde/0x1b0 kernel/sched/core.c:6631 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6690 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0xa48/0x1360 kernel/locking/mutex.c:747 tty_open_by_driver drivers/tty/tty_io.c:2043 [inline] tty_open+0x59c/0xfb0 drivers/tty/tty_io.c:2126 chrdev_open+0x26a/0x770 fs/char_dev.c:414 do_dentry_open+0x6cc/0x13f0 fs/open.c:882 do_open fs/namei.c:3557 [inline] path_openat+0x1bbc/0x2a50 fs/namei.c:3714 do_filp_open+0x1ba/0x410 fs/namei.c:3741 do_sys_openat2+0x16d/0x4c0 fs/open.c:1310 do_sys_open fs/open.c:1326 [inline] __do_sys_openat fs/open.c:1342 [inline] __se_sys_openat fs/open.c:1337 [inline] __x64_sys_openat+0x143/0x1f0 fs/open.c:1337 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: 0033:0x7f6a2903bf74 RSP: 002b:00007f6a2a241ca0 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f6a2919bf60 RCX: 00007f6a2903bf74 RDX: 0000000000000002 RSI: 00007f6a2a241d40 RDI: 00000000ffffff9c RBP: 00007f6a2a241d40 R08: 0000000000000000 R09: 000000000000000e R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000002 R13: 00007ffcf52df15f R14: 00007f6a2a242300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8c790f30 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x26/0xc70 kernel/rcu/tasks.h:507 1 lock held by rcu_tasks_trace/13: #0: ffffffff8c790c30 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x26/0xc70 kernel/rcu/tasks.h:507 1 lock held by khungtaskd/28: #0: ffffffff8c791a80 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x57/0x264 kernel/locking/lockdep.c:6494 2 locks held by getty/4746: #0: ffff888028ad0098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x26/0x80 drivers/tty/tty_ldisc.c:244 #1: ffffc900015802f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xef4/0x13e0 drivers/tty/n_tty.c:2177 2 locks held by kworker/u4:6/5609: 4 locks held by syz-executor.1/5655: 1 lock held by syz-executor.4/5657: #0: ffffffff8d20a268 (tty_mutex){+.+.}-{3:3}, at: tty_open_by_driver drivers/tty/tty_io.c:2043 [inline] #0: ffffffff8d20a268 (tty_mutex){+.+.}-{3:3}, at: tty_open+0x59c/0xfb0 drivers/tty/tty_io.c:2126 1 lock held by syz-executor.2/5662: #0: ffffffff8d20a268 (tty_mutex){+.+.}-{3:3}, at: tty_open_by_driver drivers/tty/tty_io.c:2043 [inline] #0: ffffffff8d20a268 (tty_mutex){+.+.}-{3:3}, at: tty_open+0x59c/0xfb0 drivers/tty/tty_io.c:2126 1 lock held by syz-executor.0/5661: #0: ffffffff8d20a268 (tty_mutex){+.+.}-{3:3}, at: tty_open_by_driver drivers/tty/tty_io.c:2043 [inline] #0: ffffffff8d20a268 (tty_mutex){+.+.}-{3:3}, at: tty_open+0x59c/0xfb0 drivers/tty/tty_io.c:2126 1 lock held by syz-executor.3/5828: #0: ffffffff8d20a268 (tty_mutex){+.+.}-{3:3}, at: tty_open_by_driver drivers/tty/tty_io.c:2043 [inline] #0: ffffffff8d20a268 (tty_mutex){+.+.}-{3:3}, at: tty_open+0x59c/0xfb0 drivers/tty/tty_io.c:2126 1 lock held by syz-executor.5/5865: #0: ffffffff8d20a268 (tty_mutex){+.+.}-{3:3}, at: tty_open_by_driver drivers/tty/tty_io.c:2043 [inline] #0: ffffffff8d20a268 (tty_mutex){+.+.}-{3:3}, at: tty_open+0x59c/0xfb0 drivers/tty/tty_io.c:2126 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.2.0-rc1-syzkaller-00084-gc8451c141e07 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x24/0x18a lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x333/0x3c0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xc75/0xfc0 kernel/hung_task.c:377 kthread+0x2e8/0x3a0 kernel/kthread.c:376 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:51 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt drivers/acpi/processor_idle.c:112 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_idle_do_entry+0x1fd/0x2a0 drivers/acpi/processor_idle.c:570