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.0:20305 blocked for more than 140 seconds. Not tainted 4.14.176-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D29136 20305 6374 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_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+0x410/0x9c0 drivers/tty/tty_io.c:2021 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: 0033:0x416661 RSP: 002b:00007f70f25607a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007f70f25616d4 RCX: 0000000000416661 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 00007f70f25607d0 RBP: 000000000076bf00 R08: 0000000000000000 R09: 000000000000000e R10: 0000000000000064 R11: 0000000000000293 R12: 00000000ffffffff R13: 0000000000000c0f R14: 00000000004ce414 R15: 000000000076bf0c INFO: task syz-executor.5:20321 blocked for more than 140 seconds. Not tainted 4.14.176-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28848 20321 6372 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 tty_open_by_driver drivers/tty/tty_io.c:1937 [inline] tty_open+0x352/0x9c0 drivers/tty/tty_io.c:2021 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: 0033:0x416661 RSP: 002b:00007f203e6c17a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007f203e6c26d4 RCX: 0000000000416661 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 00007f203e6c17d0 RBP: 000000000076bf00 R08: 0000000000000000 R09: 000000000000000e R10: 0000000000000064 R11: 0000000000000293 R12: 00000000ffffffff R13: 0000000000000c0f R14: 00000000004ce414 R15: 000000000076bf0c Showing all locks held in the system: 1 lock held by khungtaskd/1057: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4544 1 lock held by in:imklog/6005: #0: (&f->f_pos_lock){+.+.}, at: [] __fdget_pos+0xa6/0xc0 fs/file.c:769 2 locks held by syz-executor.0/20305: #0: (tty_mutex){+.+.}, at: [] tty_open_by_driver drivers/tty/tty_io.c:1937 [inline] #0: (tty_mutex){+.+.}, at: [] tty_open+0x352/0x9c0 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.5/20321: #0: (tty_mutex){+.+.}, at: [] tty_open_by_driver drivers/tty/tty_io.c:1937 [inline] #0: (tty_mutex){+.+.}, at: [] tty_open+0x352/0x9c0 drivers/tty/tty_io.c:2021 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1057 Comm: khungtaskd Not tainted 4.14.176-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: 20297 Comm: syz-executor.4 Not tainted 4.14.176-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff88809ed08100 task.stack: ffff88805bc48000 RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x50 kernel/kcov.c:60 RSP: 0018:ffff88805bc4f820 EFLAGS: 00000283 RAX: 0000000000040000 RBX: ffff8880000a0050 RCX: ffffc9000866a000 RDX: 0000000000040000 RSI: ffffffff831eabd3 RDI: ffff88805bc4f8d8 RBP: 0000000000000050 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880000a002a R13: 0000000000000000 R14: 00000000d0bba3bb R15: 000000000000004f FS: 00007f61de66d700(0000) GS:ffff8880aeb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b31a24000 CR3: 000000005b8fa000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 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_do_set_font+0x6b3/0x990 drivers/video/fbdev/core/fbcon.c:2563 fbcon_set_font+0x687/0x7c0 drivers/video/fbdev/core/fbcon.c:2654 con_font_set drivers/tty/vt/vt.c:4182 [inline] con_font_op+0xb73/0xf70 drivers/tty/vt/vt.c:4247 vt_ioctl+0x736/0x1f20 drivers/tty/vt/vt_ioctl.c:928 tty_ioctl+0x6c5/0x1220 drivers/tty/tty_io.c:2661 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: 0033:0x45c869 RSP: 002b:00007f61de66cc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f61de66d6d4 RCX: 000000000045c869 RDX: 00000000200000c0 RSI: 0000000000004b61 RDI: 0000000000000006 RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 000000000000041b R14: 00000000004c6c3b R15: 000000000076bf0c Code: 00 48 c7 c7 c0 90 ad 86 4c 89 3d fc bf fe 08 41 bd f4 ff ff ff e8 6c bd ee ff 48 c7 05 e6 bf fe 08 00 00 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 1b a7 a7 7e