INFO: task kworker/u4:2:28 blocked for more than 143 seconds. Not tainted 5.14.0-rc3-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:2 state:D stack:22200 pid: 28 ppid: 2 flags:0x00004000 Workqueue: events_unbound flush_to_ldisc Call Trace: context_switch kernel/sched/core.c:4683 [inline] __schedule+0xc07/0x11f0 kernel/sched/core.c:5940 schedule+0x14b/0x210 kernel/sched/core.c:6019 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6078 __mutex_lock_common+0x116f/0x3770 kernel/locking/mutex.c:1036 __mutex_lock kernel/locking/mutex.c:1104 [inline] mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:1119 flush_to_ldisc+0x37/0x510 drivers/tty/tty_buffer.c:515 process_one_work+0x833/0x10c0 kernel/workqueue.c:2276 worker_thread+0xac1/0x1320 kernel/workqueue.c:2422 kthread+0x453/0x480 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 INFO: task agetty:21316 blocked for more than 143 seconds. Not tainted 5.14.0-rc3-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:agetty state:D stack:25744 pid:21316 ppid: 1 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:4683 [inline] __schedule+0xc07/0x11f0 kernel/sched/core.c:5940 schedule+0x14b/0x210 kernel/sched/core.c:6019 schedule_timeout+0x98/0x2f0 kernel/time/timer.c:1855 down_write_failed+0x357/0x8a0 drivers/tty/tty_ldsem.c:262 __ldsem_down_write_nested drivers/tty/tty_ldsem.c:324 [inline] ldsem_down_write+0xa9/0xe0 drivers/tty/tty_ldsem.c:366 __tty_ldisc_lock drivers/tty/tty_ldisc.c:300 [inline] tty_ldisc_lock+0x6a/0xb0 drivers/tty/tty_ldisc.c:324 tty_ldisc_hangup+0x25c/0x7e0 drivers/tty/tty_ldisc.c:738 __tty_hangup+0x4e5/0x730 drivers/tty/tty_io.c:639 disassociate_ctty+0x227/0x6e0 drivers/tty/tty_jobctrl.c:275 do_exit+0x6ef/0x2510 kernel/exit.c:823 do_group_exit+0x168/0x2d0 kernel/exit.c:922 __do_sys_exit_group+0x13/0x20 kernel/exit.c:933 __se_sys_exit_group+0x10/0x10 kernel/exit.c:931 __x64_sys_exit_group+0x37/0x40 kernel/exit.c:931 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f3472f9e618 RSP: 002b:00007ffcff4a2498 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f3472f9e618 RDX: 0000000000000001 RSI: 000000000000003c RDI: 0000000000000001 RBP: 00007f347327b8e0 R08: 00000000000000e7 R09: ffffffffffffff98 R10: 00007ffcff4a2418 R11: 0000000000000246 R12: 00007f347327b8e0 R13: 00007f3473280c20 R14: 0000000000000001 R15: 000000000000000a INFO: task syz-executor.4:21517 blocked for more than 143 seconds. Not tainted 5.14.0-rc3-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.4 state:D stack:26608 pid:21517 ppid: 8458 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:4683 [inline] __schedule+0xc07/0x11f0 kernel/sched/core.c:5940 schedule+0x14b/0x210 kernel/sched/core.c:6019 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6078 __mutex_lock_common+0x116f/0x3770 kernel/locking/mutex.c:1036 __mutex_lock kernel/locking/mutex.c:1104 [inline] mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:1119 tty_release+0xac/0xef0 drivers/tty/tty_io.c:1753 __fput+0x352/0x7b0 fs/file_table.c:280 task_work_run+0x146/0x1c0 kernel/task_work.c:164 get_signal+0x1fd9/0x2080 kernel/signal.c:2581 arch_do_signal_or_restart+0x8e/0x6d0 arch/x86/kernel/signal.c:865 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x191/0x220 kernel/entry/common.c:209 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x26/0x60 kernel/entry/common.c:302 do_syscall_64+0x4c/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665e9 RSP: 002b:00007fdd173d4188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: fffffffffffffffc RBX: 000000000056bf80 RCX: 00000000004665e9 RDX: 0000000020000100 RSI: 000000000000541c RDI: 0000000000000003 RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007fff6be65b6f R14: 00007fdd173d4300 R15: 0000000000022000 Showing all locks held in the system: 3 locks held by kworker/u4:2/28: #0: ffff888011069138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7aa/0x10c0 kernel/workqueue.c:2249 #1: ffffc90000e3fd20 ((work_completion)(&buf->work)){+.+.}-{0:0}, at: process_one_work+0x7e8/0x10c0 kernel/workqueue.c:2251 #2: ffff8880849a10b8 (&buf->lock){+.+.}-{3:3}, at: flush_to_ldisc+0x37/0x510 drivers/tty/tty_buffer.c:515 1 lock held by khungtaskd/1630: #0: ffffffff8c7177c0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 arch/x86/pci/mmconfig_64.c:151 1 lock held by in:imklog/8129: #0: ffff88802b64ad70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x24e/0x2f0 fs/file.c:974 1 lock held by syz-executor.4/21188: #0: ffff8880899df1c0 (&tty->legacy_mutex){+.+.}-{3:3}, at: tty_release+0xac/0xef0 drivers/tty/tty_io.c:1753 2 locks held by agetty/21316: #0: ffff8880899df1c0 (&tty->legacy_mutex){+.+.}-{3:3}, at: __tty_hangup+0xc3/0x730 drivers/tty/tty_io.c:599 #1: ffff8880899df098 (&tty->ldisc_sem){++++}-{0:0}, at: __tty_ldisc_lock drivers/tty/tty_ldisc.c:300 [inline] #1: ffff8880899df098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock+0x6a/0xb0 drivers/tty/tty_ldisc.c:324 1 lock held by syz-executor.4/21517: #0: ffff8880899df1c0 (&tty->legacy_mutex){+.+.}-{3:3}, at: tty_release+0xac/0xef0 drivers/tty/tty_io.c:1753 2 locks held by syz-executor.3/21528: #0: ffff8880899df098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffff8880849a10b8 (&buf->lock){+.+.}-{3:3}, at: paste_selection+0x155/0x500 drivers/tty/vt/selection.c:390 1 lock held by syz-executor.3/21543: #0: ffff8880899df1c0 (&tty->legacy_mutex){+.+.}-{3:3}, at: tty_lock_interruptible+0xa4/0x140 drivers/tty/tty_mutex.c:31 1 lock held by syz-executor.3/21563: #0: ffff8880899df1c0 (&tty->legacy_mutex){+.+.}-{3:3}, at: tty_lock_interruptible+0xa4/0x140 drivers/tty/tty_mutex.c:31 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1630 Comm: khungtaskd Not tainted 5.14.0-rc3-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+0x1d3/0x29f lib/dump_stack.c:105 nmi_cpu_backtrace+0x16c/0x190 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x191/0x2f0 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+0xd06/0xd50 kernel/hung_task.c:295 kthread+0x453/0x480 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 13988 Comm: kworker/u4:8 Not tainted 5.14.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:lock_is_held_type+0x13d/0x180 kernel/locking/lockdep.c:5673 Code: 00 75 46 41 f7 c4 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 48 3b 44 24 08 75 3c 89 d8 48 83 c4 10 5b 41 5c 41 5d 41 5e <41> 5f 5d c3 0f 0b 48 c7 c7 40 c2 2e 8a e8 b1 10 00 00 65 c7 05 a6 RSP: 0018:ffffc90003ec7988 EFLAGS: 00000282 RAX: 0000000000000000 RBX: 1ffff920007d8f34 RCX: 0000000080000001 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000002 R08: dffffc0000000000 R09: fffffbfff1b74b36 R10: fffffbfff1b74b36 R11: 0000000000000000 R12: dffffc0000000000 R13: 1ffff920007d8f58 R14: dffffc0000000000 R15: ffffffff8c717720 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa721cd9000 CR3: 00000000351d5000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_is_held include/linux/lockdep.h:283 [inline] rcu_read_lock_sched_held+0x87/0x110 kernel/rcu/update.c:125 trace_lock_acquire+0x59/0x190 include/trace/events/lock.h:13 lock_acquire+0xa4/0x4a0 kernel/locking/lockdep.c:5596 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:267 rcu_read_lock include/linux/rcupdate.h:687 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:404 [inline] batadv_nc_worker+0xc8/0x5b0 net/batman-adv/network-coding.c:715 process_one_work+0x833/0x10c0 kernel/workqueue.c:2276 worker_thread+0xac1/0x1320 kernel/workqueue.c:2422 kthread+0x453/0x480 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295