INFO: task syz-executor.3:14134 blocked for more than 140 seconds. Not tainted 4.14.182-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D28912 14134 4202 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x8a6/0x1d70 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+0x5f0/0x1430 kernel/locking/mutex.c:893 tty_open_by_driver drivers/tty/tty_io.c:1937 [inline] tty_open+0x321/0x860 drivers/tty/tty_io.c:2021 chrdev_open+0x1fc/0x540 fs/char_dev.c:423 do_dentry_open+0x44b/0xec0 fs/open.c:777 vfs_open+0x105/0x220 fs/open.c:888 do_last fs/namei.c:3428 [inline] path_openat+0xb68/0x2aa0 fs/namei.c:3569 do_filp_open+0x18e/0x250 fs/namei.c:3603 do_sys_open+0x292/0x3e0 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x416821 RSP: 002b:00007fc8814997a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00000000005094c0 RCX: 0000000000416821 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 00007fc8814997d0 RBP: 000000000078bfa0 R08: 0000000000000000 R09: 000000000000000d R10: 0000000000000064 R11: 0000000000000293 R12: 00000000ffffffff R13: 0000000000000c1a R14: 00000000004ce670 R15: 00007fc88149a6d4 INFO: task syz-executor.5:14139 blocked for more than 140 seconds. Not tainted 4.14.182-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28480 14139 18229 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_timeout+0x86c/0xe50 kernel/time/timer.c:1723 __down_common kernel/locking/semaphore.c:221 [inline] __down+0x17f/0x280 kernel/locking/semaphore.c:238 down+0x57/0x80 kernel/locking/semaphore.c:62 console_lock+0x24/0x70 kernel/printk/printk.c:2216 con_install+0x46/0x490 drivers/tty/vt/vt.c:2891 tty_driver_install_tty drivers/tty/tty_io.c:1225 [inline] tty_init_dev drivers/tty/tty_io.c:1338 [inline] tty_init_dev+0xe1/0x3a0 drivers/tty/tty_io.c:1315 tty_open_by_driver drivers/tty/tty_io.c:1973 [inline] tty_open+0x5e6/0x860 drivers/tty/tty_io.c:2021 chrdev_open+0x1fc/0x540 fs/char_dev.c:423 do_dentry_open+0x44b/0xec0 fs/open.c:777 vfs_open+0x105/0x220 fs/open.c:888 do_last fs/namei.c:3428 [inline] path_openat+0xb68/0x2aa0 fs/namei.c:3569 do_filp_open+0x18e/0x250 fs/namei.c:3603 do_sys_open+0x292/0x3e0 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x416821 RSP: 002b:00007efdf27237a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000509500 RCX: 0000000000416821 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 00007efdf27237d0 RBP: 000000000078bf00 R08: 0000000000000000 R09: 000000000000000e R10: 0000000000000064 R11: 0000000000000293 R12: 00000000ffffffff R13: 0000000000000c1b R14: 00000000004ce682 R15: 00007efdf27246d4 INFO: task syz-executor.5:14141 blocked for more than 140 seconds. Not tainted 4.14.182-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28288 14141 18229 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x8a6/0x1d70 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+0x5f0/0x1430 kernel/locking/mutex.c:893 tty_open_by_driver drivers/tty/tty_io.c:1937 [inline] tty_open+0x321/0x860 drivers/tty/tty_io.c:2021 chrdev_open+0x1fc/0x540 fs/char_dev.c:423 do_dentry_open+0x44b/0xec0 fs/open.c:777 vfs_open+0x105/0x220 fs/open.c:888 do_last fs/namei.c:3428 [inline] path_openat+0xb68/0x2aa0 fs/namei.c:3569 do_filp_open+0x18e/0x250 fs/namei.c:3603 do_sys_open+0x292/0x3e0 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x416821 RSP: 002b:00007efdf27027a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000509500 RCX: 0000000000416821 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 00007efdf27027d0 RBP: 000000000078bfa0 R08: 0000000000000000 R09: 000000000000000e R10: 0000000000000064 R11: 0000000000000293 R12: 00000000ffffffff R13: 0000000000000c1b R14: 00000000004ce682 R15: 00007efdf27036d4 Showing all locks held in the system: 1 lock held by khungtaskd/1056: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 1 lock held by in:imklog/5928: #0: (&f->f_pos_lock){+.+.}, at: [] __fdget_pos+0xa6/0xc0 fs/file.c:769 2 locks held by agetty/6008: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e4/0x16e0 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.3/14134: #0: (tty_mutex){+.+.}, at: [] tty_open_by_driver drivers/tty/tty_io.c:1937 [inline] #0: (tty_mutex){+.+.}, at: [] tty_open+0x321/0x860 drivers/tty/tty_io.c:2021 2 locks held by syz-executor.5/14139: #0: (tty_mutex){+.+.}, at: [] tty_open_by_driver drivers/tty/tty_io.c:1937 [inline] #0: (tty_mutex){+.+.}, at: [] tty_open+0x321/0x860 drivers/tty/tty_io.c:2021 #1: (&tty->legacy_mutex){+.+.}, at: [] tty_lock+0x5f/0x70 drivers/tty/tty_mutex.c:19 1 lock held by syz-executor.5/14141: #0: (tty_mutex){+.+.}, at: [] tty_open_by_driver drivers/tty/tty_io.c:1937 [inline] #0: (tty_mutex){+.+.}, at: [] tty_open+0x321/0x860 drivers/tty/tty_io.c:2021 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1056 Comm: khungtaskd Not tainted 4.14.182-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+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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 14132 Comm: syz-executor.3 Not tainted 4.14.182-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff88801545e3c0 task.stack: ffff88808c268000 RIP: 0010:__writeq arch/x86/include/asm/io.h:100 [inline] RIP: 0010:bitfill_aligned drivers/video/fbdev/core/cfbfillrect.c:69 [inline] RIP: 0010:bitfill_aligned+0xe7/0x190 drivers/video/fbdev/core/cfbfillrect.c:35 RSP: 0018:ffff88808c26f108 EFLAGS: 00000246 RAX: 0000000000040000 RBX: ffff8880000a0080 RCX: ffffc90008d17000 RDX: 0000000000040000 RSI: ffffffff831c0be4 RDI: 0000000000000a00 RBP: 0000000000000028 R08: 0000000000000a00 R09: 0000000000000040 R10: ffffed1014bec01b R11: ffff8880a5f600df R12: ffff8880000a0140 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007fc8814bb700(0000) GS:ffff8880aec00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c009b31ac0 CR3: 000000009ff05000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: cfb_fillrect+0x3d5/0x720 drivers/video/fbdev/core/cfbfillrect.c:327 vga16fb_fillrect+0x61e/0x1880 drivers/video/fbdev/vga16fb.c:951 bit_clear_margins+0x2a4/0x480 drivers/video/fbdev/core/bitblit.c:232 fbcon_clear_margins+0x274/0x300 drivers/video/fbdev/core/fbcon.c:1320 ypan_up_redraw drivers/video/fbdev/core/fbcon.c:1505 [inline] fbcon_scroll+0xcd6/0x33c0 drivers/video/fbdev/core/fbcon.c:1883 con_scroll+0x294/0x310 drivers/tty/vt/vt.c:327 lf+0x226/0x270 drivers/tty/vt/vt.c:1134 do_con_trol+0x493/0x52e0 drivers/tty/vt/vt.c:1797 do_con_write.part.0+0xc44/0x1a20 drivers/tty/vt/vt.c:2447 do_con_write drivers/tty/vt/vt.c:2218 [inline] con_write+0x33/0xc0 drivers/tty/vt/vt.c:2798 do_output_char+0x4f5/0x750 drivers/tty/n_tty.c:447 process_output drivers/tty/n_tty.c:514 [inline] n_tty_write+0x409/0xe20 drivers/tty/n_tty.c:2345 do_tty_write drivers/tty/tty_io.c:959 [inline] tty_write+0x3f1/0x6e0 drivers/tty/tty_io.c:1043 __vfs_write+0xe4/0x630 fs/read_write.c:480 __kernel_write+0xf5/0x330 fs/read_write.c:501 write_pipe_buf+0x143/0x1b0 fs/splice.c:797 splice_from_pipe_feed fs/splice.c:502 [inline] __splice_from_pipe+0x332/0x740 fs/splice.c:626 splice_from_pipe+0xc6/0x120 fs/splice.c:661 default_file_splice_write+0x37/0x80 fs/splice.c:809 do_splice_from fs/splice.c:851 [inline] direct_splice_actor+0x115/0x160 fs/splice.c:1018 splice_direct_to_actor+0x27e/0x730 fs/splice.c:973 do_splice_direct+0x164/0x210 fs/splice.c:1061 do_sendfile+0x469/0xaf0 fs/read_write.c:1441 SYSC_sendfile64 fs/read_write.c:1502 [inline] SyS_sendfile64+0xff/0x110 fs/read_write.c:1488 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x45ca29 RSP: 002b:00007fc8814bac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00000000004fc540 RCX: 000000000045ca29 RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000003 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0800000080004103 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000008dc R14: 00000000004cba16 R15: 00007fc8814bb6d4 Code: 44 8d 60 f8 41 c1 ec 03 49 83 c4 01 49 c1 e4 06 49 01 dc e8 2c 96 3e fe 4c 89 3b 4c 89 7b 08 4c 89 7b 10 4c 89 7b 18 4c 89 7b 20 <4c> 89 7b 28 48 8d 43 38 4c 89 7b 30 48 83 c3 40 4c 89 38 49 39