INFO: task hung in con

Kernel	Title	Count	Last	Reported	Patched	Status
upstream	INFO: task hung in con_write (2) serial	3	1392d	1440d	0/26	auto-closed as invalid on 2020/10/13 06:51
linux-4.19	INFO: task hung in con_write	2	1420d	1487d	0/1	auto-closed as invalid on 2020/10/15 09:20
upstream	INFO: task hung in con_write serial	1	1604d	1604d	0/26	auto-closed as invalid on 2020/03/14 17:26

NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 INFO: task syz-executor.5:19182 blocked for more than 140 seconds. Not tainted 4.14.180-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28528 19182 6355 0x00000004 Call Trace: schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_timeout+0x946/0xe40 kernel/time/timer.c:1723 __down_common kernel/locking/semaphore.c:221 [inline] __down+0x160/0x290 kernel/locking/semaphore.c:238 down+0x57/0x80 kernel/locking/semaphore.c:62 console_lock+0x24/0x70 kernel/printk/printk.c:2216 con_flush_chars drivers/tty/vt/vt.c:2875 [inline] con_flush_chars drivers/tty/vt/vt.c:2867 [inline] con_write+0x60/0xc0 drivers/tty/vt/vt.c:2799 process_output_block drivers/tty/n_tty.c:595 [inline] n_tty_write+0x375/0xe30 drivers/tty/n_tty.c:2333 do_tty_write drivers/tty/tty_io.c:959 [inline] tty_write+0x3f0/0x700 drivers/tty/tty_io.c:1043 do_loop_readv_writev fs/read_write.c:698 [inline] do_loop_readv_writev fs/read_write.c:682 [inline] do_iter_write fs/read_write.c:956 [inline] do_iter_write+0x3d9/0x550 fs/read_write.c:935 vfs_writev+0x170/0x2a0 fs/read_write.c:999 do_writev+0xfc/0x2c0 fs/read_write.c:1034 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45ca29 RSP: 002b:00007f570bccfc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 000000000050d640 RCX: 000000000045ca29 RDX: 0000000000000001 RSI: 0000000020000080 RDI: 0000000000000004 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000d20 R14: 00000000004cb469 R15: 00007f570bcd06d4 INFO: task syz-executor.5:19221 blocked for more than 140 seconds. Not tainted 4.14.180-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D29616 19221 6355 0x00000004 Call Trace: schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_timeout+0x946/0xe40 kernel/time/timer.c:1723 __down_common kernel/locking/semaphore.c:221 [inline] __down+0x160/0x290 kernel/locking/semaphore.c:238 down+0x57/0x80 kernel/locking/semaphore.c:62 console_lock+0x24/0x70 kernel/printk/printk.c:2216 vcs_open+0x3d/0x80 drivers/tty/vt/vc_screen.c:599 chrdev_open+0x1fc/0x540 fs/char_dev.c:423 do_dentry_open+0x732/0xe90 fs/open.c:777 vfs_open+0x105/0x220 fs/open.c:888 do_last fs/namei.c:3428 [inline] path_openat+0x8ca/0x3c50 fs/namei.c:3569 do_filp_open+0x18e/0x250 fs/namei.c:3603 do_sys_open+0x29d/0x3f0 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45ca29 RSP: 002b:00007f570bc6cc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00000000004f9080 RCX: 000000000045ca29 RDX: 0000000000103c00 RSI: 0000000020000240 RDI: ffffffffffffff9c RBP: 000000000078c0e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000809 R14: 00000000004cae4e R15: 00007f570bc6d6d4 INFO: task syz-executor.4:19223 blocked for more than 140 seconds. Not tainted 4.14.180-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D29424 19223 6358 0x00000004 Call Trace: 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+0x73c/0x1470 kernel/locking/mutex.c:893 fb_open+0xb7/0x400 drivers/video/fbdev/core/fbmem.c:1468 chrdev_open+0x1fc/0x540 fs/char_dev.c:423 do_dentry_open+0x732/0xe90 fs/open.c:777 vfs_open+0x105/0x220 fs/open.c:888 do_last fs/namei.c:3428 [inline] path_openat+0x8ca/0x3c50 fs/namei.c:3569 do_filp_open+0x18e/0x250 fs/namei.c:3603 do_sys_open+0x29d/0x3f0 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45ca29 RSP: 002b:00007fa68d6b6c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00000000004f7640 RCX: 000000000045ca29 RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000078c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000007a0 R14: 00000000004ca744 R15: 00007fa68d6b76d4 Showing all locks held in the system: 1 lock held by khungtaskd/1056: #0: (tasklist_lock){.+.?}, at: [<ffffffff81465d33>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 1 lock held by in:imklog/6033: #0: (&f->f_pos_lock){+.+.}, at: [<ffffffff8191bb06>] __fdget_pos+0xa6/0xc0 fs/file.c:769 4 locks held by syz-executor.5/19182: #0: (&tty->ldisc_sem){++++}, at: [<ffffffff833b1c62>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&tty->atomic_write_lock){+.+.}, at: [<ffffffff833977cd>] tty_write_lock+0x1d/0x60 drivers/tty/tty_io.c:885 #2: (&tty->termios_rwsem){++++}, at: [<ffffffff833a43e7>] n_tty_write+0x187/0xe30 drivers/tty/n_tty.c:2316 #3: (&ldata->output_lock){+.+.}, at: [<ffffffff833a46c4>] process_output_block drivers/tty/n_tty.c:550 [inline] #3: (&ldata->output_lock){+.+.}, at: [<ffffffff833a46c4>] n_tty_write+0x464/0xe30 drivers/tty/n_tty.c:2333 1 lock held by syz-executor.4/19223: #0: (&fb_info->lock){+.+.}, at: [<ffffffff83174827>] fb_open+0xb7/0x400 drivers/video/fbdev/core/fbmem.c:1468 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1056 Comm: khungtaskd Not tainted 4.14.180-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+0x13e/0x194 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x139/0x17e 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+0x5e2/0xb80 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 CPU: 1 PID: 19195 Comm: syz-executor.4 Not tainted 4.14.180-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8880503466c0 task.stack: ffff88821ad38000 RIP: 0010:__sanitizer_cov_trace_pc+0x23/0x50 kernel/kcov.c:68 RSP: 0018:ffff88821ad3f3c8 EFLAGS: 00000246 RAX: ffff8880503466c0 RBX: ffff8880000a0050 RCX: ffffc9000b89b000 RDX: 0000000000000001 RSI: ffffffff831ed0e3 RDI: ffff88821ad3f480 RBP: 0000000000000050 R08: 000000000000ffff R09: ffffed1043239164 R10: ffffed1043239163 R11: ffff8882191c8b1f R12: ffff8880000a004b R13: 0000000000000000 R14: 00000000db4bbe1d R15: 000000000000004f FS: 00007fa68d6f9700(0000) GS:ffff8880aeb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000563fefde4908 CR3: 0000000052e76000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: writeb arch/x86/include/asm/io.h:65 [inline] vga16fb_fillrect+0x943/0x1880 drivers/video/fbdev/vga16fb.c:923 bit_clear_margins+0x2a4/0x480 drivers/video/fbdev/core/bitblit.c:232 fbcon_clear_margins+0x285/0x310 drivers/video/fbdev/core/fbcon.c:1320 fbcon_switch+0xcdf/0x1780 drivers/video/fbdev/core/fbcon.c:2302 redraw_screen+0x331/0x770 drivers/tty/vt/vt.c:689 fbcon_modechanged+0x59d/0x890 drivers/video/fbdev/core/fbcon.c:2949 fbcon_event_notify+0x11a/0x1746 drivers/video/fbdev/core/fbcon.c:3302 notifier_call_chain+0x107/0x1a0 kernel/notifier.c:93 __blocking_notifier_call_chain kernel/notifier.c:317 [inline] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] blocking_notifier_call_chain kernel/notifier.c:328 [inline] blocking_notifier_call_chain+0x79/0x90 kernel/notifier.c:325 fb_set_var+0xaad/0xc70 drivers/video/fbdev/core/fbmem.c:1054 do_fb_ioctl+0x3cc/0x840 drivers/video/fbdev/core/fbmem.c:1127 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1242 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xfe0 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+0x42/0xb7 RIP: 0033:0x45ca29 RSP: 002b:00007fa68d6f8c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004e4ac0 RCX: 000000000045ca29 RDX: 0000000020000000 RSI: 0000000000004601 RDI: 0000000000000008 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000002f2 R14: 00000000004c56c8 R15: 00007fa68d6f96d4 Code: 00 00 e9 be ed ff ff 90 65 48 8b 04 25 40 ee 01 00 48 85 c0 74 1a 65 8b 15 fb a7 a7 7e 81 e2 00 01 1f 00 75 0b 8b 90 58 13 00 00 <83> fa 01 74 01 c3 48 8b 34 24 48 8b 88 60 13 00 00 8b 80 5c 13