INFO: task kworker/u4:3:121 blocked for more than 143 seconds. Not tainted 5.14.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:3 state:D stack:18584 pid: 121 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 syz-executor558:8565 blocked for more than 143 seconds. Not tainted 5.14.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor558 state:D stack:25496 pid: 8565 ppid: 8458 flags:0x00004004 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 set_selection_kernel+0x27/0x17d0 drivers/tty/vt/selection.c:357 set_selection_user+0xaa/0xe0 drivers/tty/vt/selection.c:185 vt_ioctl+0x455/0x37b0 drivers/tty/vt/vt_ioctl.c:760 tty_ioctl+0xf51/0x1720 drivers/tty/tty_io.c:2805 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:1069 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:1055 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: 0033:0x443859 RSP: 002b:00007ffe12f3c308 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000443859 RDX: 0000000020000000 RSI: 000000000000541c RDI: 0000000000000003 RBP: 0000000000000000 R08: 000000000000000e R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe12f3c348 R13: 00007ffe12f3c360 R14: 00007ffe12f3c3a0 R15: 0000000000000027 Showing all locks held in the system: 3 locks held by kworker/u4:3/121: #0: ffff888011069138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7aa/0x10c0 kernel/workqueue.c:2249 #1: ffffc9000130fd20 ((work_completion)(&buf->work)){+.+.}-{0:0}, at: process_one_work+0x7e8/0x10c0 kernel/workqueue.c:2251 #2: ffff8880317940b8 (&buf->lock){+.+.}-{3:3}, at: flush_to_ldisc+0x37/0x510 drivers/tty/tty_buffer.c:515 1 lock held by khungtaskd/1645: #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/8147: #0: ffff888016df6870 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x24e/0x2f0 fs/file.c:974 3 locks held by syz-executor558/8564: 1 lock held by syz-executor558/8565: #0: ffffffff8cdda7c8 (vc_sel.lock){+.+.}-{3:3}, at: set_selection_kernel+0x27/0x17d0 drivers/tty/vt/selection.c:357 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1645 Comm: khungtaskd Not tainted 5.14.0-rc4-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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 8564 Comm: syz-executor558 Not tainted 5.14.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:check_kcov_mode kernel/kcov.c:165 [inline] RIP: 0010:write_comp_data kernel/kcov.c:218 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x2b/0x90 kernel/kcov.c:291 Code: 8b 04 24 65 48 8b 14 25 80 ef 01 00 65 8b 05 14 c6 81 7e a9 00 01 ff 00 74 10 a9 00 01 00 00 74 6a 83 ba 34 15 00 00 00 74 61 <8b> 82 10 15 00 00 83 f8 03 75 56 48 8b 8a 18 15 00 00 44 8b 8a 14 RSP: 0018:ffffc9000160f6d8 EFLAGS: 00000246 RAX: 0000000080000000 RBX: 0000000000004002 RCX: ffffffff84752084 RDX: ffff8880296dd4c0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000160f7f0 R08: ffffffff847520ab R09: ffffed10052dba99 R10: ffffed10052dba99 R11: 0000000000000000 R12: ffff888146207438 R13: ffff8880296dd4c0 R14: dffffc0000000000 R15: dffffc0000000000 FS: 0000000001e513c0(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000004bdee8 CR3: 0000000014be1000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: paste_selection+0x28b/0x500 drivers/tty/vt/selection.c:396 vt_ioctl+0x455/0x37b0 drivers/tty/vt/vt_ioctl.c:760 tty_ioctl+0xf51/0x1720 drivers/tty/tty_io.c:2805 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:1069 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:1055 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: 0033:0x443859 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 d1 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:00007ffe12f3c308 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000443859 RDX: 0000000020000000 RSI: 000000000000541c RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000000e R11: 0000000000000246 R12: 00007ffe12f3c348 R13: 00007ffe12f3c360 R14: 00007ffe12f3c3a0 R15: 0000000000000026