INFO: task kworker/u4:0:8 blocked for more than 143 seconds. Not tainted 5.14.0-rc2-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:0 state:D stack:24104 pid: 8 ppid: 2 flags:0x00004000 Workqueue: events_unbound flush_to_ldisc Call Trace: context_switch kernel/sched/core.c:4683 [inline] __schedule+0x93a/0x26f0 kernel/sched/core.c:5940 schedule+0xd3/0x270 kernel/sched/core.c:6019 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6078 __mutex_lock_common kernel/locking/mutex.c:1036 [inline] __mutex_lock+0x7b6/0x10a0 kernel/locking/mutex.c:1104 flush_to_ldisc+0x3e/0x380 drivers/tty/tty_buffer.c:515 process_one_work+0x98d/0x1630 kernel/workqueue.c:2276 worker_thread+0x658/0x11f0 kernel/workqueue.c:2422 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 INFO: task syz-executor035:8505 blocked for more than 143 seconds. Not tainted 5.14.0-rc2-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor035 state:D stack:28176 pid: 8505 ppid: 8447 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4683 [inline] __schedule+0x93a/0x26f0 kernel/sched/core.c:5940 schedule+0xd3/0x270 kernel/sched/core.c:6019 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6078 __mutex_lock_common kernel/locking/mutex.c:1036 [inline] __mutex_lock+0x7b6/0x10a0 kernel/locking/mutex.c:1104 set_selection_kernel drivers/tty/vt/selection.c:357 [inline] set_selection_user+0x9f/0x1b0 drivers/tty/vt/selection.c:185 tioclinux+0x114/0x560 drivers/tty/vt/vt.c:3160 vt_ioctl+0x225f/0x2ac0 drivers/tty/vt/vt_ioctl.c:760 tty_ioctl+0xe4d/0x1600 drivers/tty/tty_io.c:2805 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:1069 [inline] __se_sys_ioctl fs/ioctl.c:1055 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:1055 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4412a9 RSP: 002b:00007ffd8b8eef98 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000172c20 RCX: 00000000004412a9 RDX: 0000000020000000 RSI: 000000000000541c RDI: 0000000000000003 RBP: 0000000000000000 R08: 000000000000000e R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd8b8eefdc R13: 00007ffd8b8ef010 R14: 00007ffd8b8eeff0 R15: 0000000000000015 Showing all locks held in the system: 3 locks held by kworker/u4:0/8: #0: ffff888010869138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888010869138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:620 [inline] #0: ffff888010869138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888010869138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:617 [inline] #0: ffff888010869138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: ffff888010869138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x871/0x1630 kernel/workqueue.c:2247 #1: ffffc90000cd7db0 ((work_completion)(&buf->work)){+.+.}-{0:0}, at: process_one_work+0x8a5/0x1630 kernel/workqueue.c:2251 #2: ffff8880210310b8 (&buf->lock){+.+.}-{3:3}, at: flush_to_ldisc+0x3e/0x380 drivers/tty/tty_buffer.c:515 1 lock held by khungtaskd/1651: #0: ffffffff8b97b9c0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6446 1 lock held by in:imklog/8139: #0: ffff88802aa319f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:974 3 locks held by syz-executor035/8503: 1 lock held by syz-executor035/8505: #0: ffffffff8c3855c8 (vc_sel.lock){+.+.}-{3:3}, at: set_selection_kernel drivers/tty/vt/selection.c:357 [inline] #0: ffffffff8c3855c8 (vc_sel.lock){+.+.}-{3:3}, at: set_selection_user+0x9f/0x1b0 drivers/tty/vt/selection.c:185 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1651 Comm: khungtaskd Not tainted 5.14.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:105 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline] watchdog+0xd0a/0xfc0 kernel/hung_task.c:295 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 8503 Comm: syz-executor035 Not tainted 5.14.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:paste_selection+0x2c1/0x4c0 drivers/tty/vt/selection.c:396 Code: be 08 00 00 00 48 89 df e8 3c 40 8d fd 41 80 3e 00 0f 85 c3 01 00 00 48 8b 03 31 ff 83 e0 04 49 89 c7 48 89 c6 e8 5f 11 47 fd <4d> 85 ff 0f 85 88 00 00 00 e8 f1 0b 47 fd 4d 8d bd 38 04 00 00 be RSP: 0018:ffffc900016ffa88 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff8880246cd4c0 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff8880246cd4c0 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: ffff8880246cd4c7 R10: ffffffff842e7cd1 R11: 0000000000000000 R12: dffffc0000000000 R13: ffff888028323000 R14: ffffed10048d9a98 R15: 0000000000000000 FS: 00000000016363c0(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000001636384 CR3: 00000000211b9000 CR4: 0000000000350ee0 Call Trace: tioclinux+0x126/0x560 drivers/tty/vt/vt.c:3164 vt_ioctl+0x225f/0x2ac0 drivers/tty/vt/vt_ioctl.c:760 tty_ioctl+0xe4d/0x1600 drivers/tty/tty_io.c:2805 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:1069 [inline] __se_sys_ioctl fs/ioctl.c:1055 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:1055 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4412a9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 11 15 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c4 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd8b8eef98 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000063 RCX: 00000000004412a9 RDX: 0000000020000000 RSI: 000000000000541c RDI: 0000000000000003 RBP: 0000000000000063 R08: 000000000000000e R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd8b8eefdc R13: 00007ffd8b8ef010 R14: 00007ffd8b8eeff0 R15: 0000000000000014