INFO: task login:7636 blocked for more than 140 seconds. Not tainted 4.19.92-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. login D24416 7636 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x866/0x1dc0 kernel/sched/core.c:3515 schedule+0x92/0x1c0 kernel/sched/core.c:3559 schedule_timeout+0x8c8/0xfc0 kernel/time/timer.c:1782 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common kernel/sched/completion.c:115 [inline] wait_for_completion+0x29c/0x440 kernel/sched/completion.c:136 __flush_work+0x49f/0x870 kernel/workqueue.c:2926 flush_work+0x18/0x20 kernel/workqueue.c:2947 tty_buffer_flush_work+0x16/0x19 drivers/tty/tty_buffer.c:613 n_tty_read+0xb1a/0x1b70 drivers/tty/n_tty.c:2197 tty_read+0x193/0x2a0 drivers/tty/tty_io.c:867 __vfs_read+0x114/0x800 fs/read_write.c:416 vfs_read+0x194/0x3d0 fs/read_write.c:452 ksys_read+0x14f/0x2d0 fs/read_write.c:579 __do_sys_read fs/read_write.c:589 [inline] __se_sys_read fs/read_write.c:587 [inline] __x64_sys_read+0x73/0xb0 fs/read_write.c:587 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7fa13cc64310 Code: Bad RIP value. RSP: 002b:00007fffdfcbaf88 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fa13cc64310 RDX: 00000000000001ff RSI: 00007fffdfcbb1f0 RDI: 0000000000000000 RBP: 0000000000000000 R08: 00007fa13d547700 R09: 0000000000000000 R10: 00007fffdfcbaf40 R11: 0000000000000246 R12: 00007fffdfcbb1f0 R13: 0000000000000000 R14: 0000000000000001 R15: 000000000060b798 INFO: task kworker/u4:15:27613 blocked for more than 140 seconds. Not tainted 4.19.92-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:15 D25432 27613 2 0x80000000 Workqueue: events_unbound flush_to_ldisc Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x866/0x1dc0 kernel/sched/core.c:3515 schedule+0x92/0x1c0 kernel/sched/core.c:3559 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3617 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 flush_to_ldisc+0x3d/0x390 drivers/tty/tty_buffer.c:500 process_one_work+0x989/0x1750 kernel/workqueue.c:2153 process_scheduled_works kernel/workqueue.c:2212 [inline] worker_thread+0x750/0xe40 kernel/workqueue.c:2301 kthread+0x354/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 INFO: task syz-executor.5:31892 blocked for more than 140 seconds. Not tainted 4.19.92-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28480 31892 19642 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x866/0x1dc0 kernel/sched/core.c:3515 schedule+0x92/0x1c0 kernel/sched/core.c:3559 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3617 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 tty_buffer_lock_exclusive+0x30/0x40 drivers/tty/tty_buffer.c:61 paste_selection+0x11d/0x443 drivers/tty/vt/selection.c:348 tioclinux+0x133/0x470 drivers/tty/vt/vt.c:3019 vt_ioctl+0x19ab/0x2530 drivers/tty/vt/vt_ioctl.c:364 tty_ioctl+0x7f3/0x1510 drivers/tty/tty_io.c:2669 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:688 ksys_ioctl+0xab/0xd0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a9e9 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f47e832ac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a9e9 RDX: 0000000020000000 RSI: 000000000000541c RDI: 0000000000000005 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f47e832b6d4 R13: 00000000004c5db9 R14: 00000000004dc4d8 R15: 00000000ffffffff INFO: task syz-executor.3:31896 blocked for more than 140 seconds. Not tainted 4.19.92-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D27536 31896 19645 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x866/0x1dc0 kernel/sched/core.c:3515 schedule+0x92/0x1c0 kernel/sched/core.c:3559 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3617 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 tty_buffer_lock_exclusive+0x30/0x40 drivers/tty/tty_buffer.c:61 paste_selection+0x11d/0x443 drivers/tty/vt/selection.c:348 tioclinux+0x133/0x470 drivers/tty/vt/vt.c:3019 vt_ioctl+0x19ab/0x2530 drivers/tty/vt/vt_ioctl.c:364 tty_ioctl+0x7f3/0x1510 drivers/tty/tty_io.c:2669 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:688 ksys_ioctl+0xab/0xd0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a9e9 Code: Bad RIP value. RSP: 002b:00007fbbd42c8c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a9e9 RDX: 0000000020000000 RSI: 000000000000541c RDI: 0000000000000005 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fbbd42c96d4 R13: 00000000004c5db9 R14: 00000000004dc4d8 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1068: #0: 00000000cc049aa7 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4438 1 lock held by rsyslogd/7511: #0: 0000000013591e1b (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:767 2 locks held by getty/7635: #0: 000000008f97365d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000debcf6a1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by login/7636: #0: 00000000773a69f9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000e78c9bed (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/7637: #0: 000000003d4f338c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000de3e0ce9 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/7638: #0: 0000000016d0ea06 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000493f990b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/7639: #0: 0000000092f18b36 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000b0df7e2f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/7640: #0: 000000003672360d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000bba5c0a2 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 3 locks held by kworker/u4:15/27613: #0: 00000000c69ced1f ((wq_completion)"events_unbound"){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline] #0: 00000000c69ced1f ((wq_completion)"events_unbound"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000c69ced1f ((wq_completion)"events_unbound"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 00000000c69ced1f ((wq_completion)"events_unbound"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 00000000c69ced1f ((wq_completion)"events_unbound"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 00000000c69ced1f ((wq_completion)"events_unbound"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 00000000c69ced1f ((wq_completion)"events_unbound"){+.+.}, at: process_one_work+0x87e/0x1750 kernel/workqueue.c:2124 #1: 000000002cfc03e6 ((work_completion)(&buf->work)){+.+.}, at: process_one_work+0x8b4/0x1750 kernel/workqueue.c:2128 #2: 00000000f569a491 (&buf->lock){+.+.}, at: flush_to_ldisc+0x3d/0x390 drivers/tty/tty_buffer.c:500 2 locks held by getty/25533: #0: 000000009315d2c3 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 0000000096a85e3e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 3 locks held by syz-executor.0/31679: 2 locks held by syz-executor.5/31892: #0: 00000000773a69f9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000f569a491 (&buf->lock){+.+.}, at: tty_buffer_lock_exclusive+0x30/0x40 drivers/tty/tty_buffer.c:61 2 locks held by syz-executor.3/31896: #0: 00000000773a69f9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000f569a491 (&buf->lock){+.+.}, at: tty_buffer_lock_exclusive+0x30/0x40 drivers/tty/tty_buffer.c:61 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1068 Comm: khungtaskd Not tainted 4.19.92-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x197/0x210 lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b0/0x1f8 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x9df/0xee0 kernel/hung_task.c:287 kthread+0x354/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 31679 Comm: syz-executor.0 Not tainted 4.19.92-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__lock_is_held+0xb1/0x140 kernel/locking/lockdep.c:3723 Code: 84 c0 74 08 3c 03 0f 8e 92 00 00 00 44 39 b3 78 08 00 00 7e 6a 48 8b 4d d0 49 63 c6 4c 89 e6 48 8d 04 80 4c 8d 3c c1 4c 89 ff 1a f9 ff ff 85 c0 74 c4 83 7d c4 ff b8 01 00 00 00 74 43 49 8d RSP: 0018:ffff88806f7ef630 EFLAGS: 00000006 RAX: 0000000000000000 RBX: ffff88809fb302c0 RCX: ffff88809fb30b40 RDX: 1ffff11013f66167 RSI: ffff8880ae82c258 RDI: ffff88809fb30b40 RBP: ffff88806f7ef670 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff8a0b2010 R11: 0000000000000001 R12: ffff8880ae82c258 R13: ffffed1013f66167 R14: 0000000000000000 R15: ffff88809fb30b40 FS: 00007f5ae35bd700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c42be1f000 CR3: 000000006b913000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_is_held_type+0x110/0x210 kernel/locking/lockdep.c:3941 lock_is_held include/linux/lockdep.h:344 [inline] rq_clock_task kernel/sched/sched.h:1000 [inline] update_curr+0x296/0x8a0 kernel/sched/fair.c:804 pick_next_task_fair+0x6bf/0x1580 kernel/sched/fair.c:6698 pick_next_task kernel/sched/core.c:3361 [inline] __schedule+0x456/0x1dc0 kernel/sched/core.c:3489 schedule+0x92/0x1c0 kernel/sched/core.c:3559 paste_selection+0x2e8/0x443 drivers/tty/vt/selection.c:354 tioclinux+0x133/0x470 drivers/tty/vt/vt.c:3019 vt_ioctl+0x19ab/0x2530 drivers/tty/vt/vt_ioctl.c:364 tty_ioctl+0x7f3/0x1510 drivers/tty/tty_io.c:2669 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:688 ksys_ioctl+0xab/0xd0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a9e9 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f5ae35bcc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a9e9 RDX: 0000000020000000 RSI: 000000000000541c RDI: 0000000000000005 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f5ae35bd6d4 R13: 00000000004c5db9 R14: 00000000004dc4d8 R15: 00000000ffffffff