Bluetooth: hci3 command 0x0406 tx timeout Bluetooth: hci0 command 0x0406 tx timeout INFO: task kworker/u4:6:7800 blocked for more than 140 seconds. Not tainted 4.14.195-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:6 D26344 7800 2 0x80000000 Workqueue: events_unbound flush_to_ldisc Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893 flush_to_ldisc+0x35/0x3f0 drivers/tty/tty_buffer.c:499 process_one_work+0x793/0x14a0 kernel/workqueue.c:2116 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2250 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 INFO: task agetty:20811 blocked for more than 140 seconds. Not tainted 4.14.195-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. agetty D27464 20811 1 0x80000002 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_timeout+0x80a/0xe90 kernel/time/timer.c:1731 down_write_failed drivers/tty/tty_ldsem.c:298 [inline] __ldsem_down_write_nested+0x2b9/0x700 drivers/tty/tty_ldsem.c:360 __tty_ldisc_lock drivers/tty/tty_ldisc.c:332 [inline] tty_ldisc_lock+0x4d/0x80 drivers/tty/tty_ldisc.c:356 tty_ldisc_hangup+0x1d3/0x6c0 drivers/tty/tty_ldisc.c:758 __tty_hangup.part.0+0x31a/0x730 drivers/tty/tty_io.c:622 __tty_hangup drivers/tty/tty_io.c:572 [inline] tty_vhangup_session+0x20/0x30 drivers/tty/tty_io.c:732 disassociate_ctty.part.0+0x98/0x6f0 drivers/tty/tty_jobctrl.c:266 disassociate_ctty+0x71/0x90 drivers/tty/tty_jobctrl.c:260 do_exit+0x1613/0x27f0 kernel/exit.c:863 do_group_exit+0x100/0x2e0 kernel/exit.c:962 SYSC_exit_group kernel/exit.c:973 [inline] SyS_exit_group+0x19/0x20 kernel/exit.c:971 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7fd9de101618 RSP: 002b:00007fffed507aa8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007fd9de101618 RDX: 0000000000000001 RSI: 000000000000003c RDI: 0000000000000001 RBP: 00007fd9de3de8e0 R08: 00000000000000e7 R09: ffffffffffffff98 R10: 00007fffed507a28 R11: 0000000000000246 R12: 00007fd9de3de8e0 R13: 00007fd9de3e3c20 R14: 0000000000000001 R15: 000000000000000a INFO: task syz-executor.1:21311 blocked for more than 140 seconds. Not tainted 4.14.195-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28360 21311 6366 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893 paste_selection+0x10e/0x414 drivers/tty/vt/selection.c:373 tioclinux+0xfd/0x490 drivers/tty/vt/vt.c:2713 vt_ioctl+0x12fb/0x1ea0 drivers/tty/vt/vt_ioctl.c:372 tty_ioctl+0x50f/0x13c0 drivers/tty/tty_io.c:2661 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x45d5b9 RSP: 002b:00007f4fb462ac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000019380 RCX: 000000000045d5b9 RDX: 0000000020000040 RSI: 000000000000541c RDI: 0000000000000009 RBP: 000000000118d160 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118d12c R13: 00007ffdb8276fcf R14: 00007f4fb462b9c0 R15: 000000000118d12c Showing all locks held in the system: 1 lock held by khungtaskd/1067: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 1 lock held by in:imklog/6019: #0: (&f->f_pos_lock){+.+.}, at: [] __fdget_pos+0x1fb/0x2b0 fs/file.c:769 3 locks held by kworker/u4:6/7800: #0: ("events_unbound"){+.+.}, at: [] process_one_work+0x6b0/0x14a0 kernel/workqueue.c:2087 #1: ((&buf->work)){+.+.}, at: [] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2091 #2: (&buf->lock){+.+.}, at: [] flush_to_ldisc+0x35/0x3f0 drivers/tty/tty_buffer.c:499 1 lock held by syz-executor.1/17617: #0: (&tty->legacy_mutex){+.+.}, at: [] tty_lock+0x5f/0x70 drivers/tty/tty_mutex.c:19 2 locks held by agetty/20811: #0: (&tty->legacy_mutex){+.+.}, at: [] tty_lock+0x5f/0x70 drivers/tty/tty_mutex.c:19 #1: (&tty->ldisc_sem){++++}, at: [] __tty_ldisc_lock drivers/tty/tty_ldisc.c:332 [inline] #1: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_lock+0x4d/0x80 drivers/tty/tty_ldisc.c:356 2 locks held by syz-executor.0/21252: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&buf->lock){+.+.}, at: [] paste_selection+0x10e/0x414 drivers/tty/vt/selection.c:373 2 locks held by syz-executor.1/21311: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&buf->lock){+.+.}, at: [] paste_selection+0x10e/0x414 drivers/tty/vt/selection.c:373 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1067 Comm: khungtaskd Not tainted 4.14.195-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x283 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x13a/0x17f lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x5b9/0xb40 kernel/hung_task.c:274 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at pc 0xffffffff86547e8e