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.0:19227 blocked for more than 140 seconds. Not tainted 4.14.184-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D29296 19227 6352 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 do_con_write.part.0+0x8c/0x1a20 drivers/tty/vt/vt.c:2223 do_con_write drivers/tty/vt/vt.c:2218 [inline] con_write+0x33/0xc0 drivers/tty/vt/vt.c:2798 process_output_block drivers/tty/n_tty.c:595 [inline] n_tty_write+0x375/0xe20 drivers/tty/n_tty.c:2333 do_tty_write drivers/tty/tty_io.c:959 [inline] tty_write+0x3f1/0x6e0 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+0x133/0x2a0 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+0x46/0xbb RIP: 0033:0x45cb19 RSP: 002b:00007fe6ab421c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 000000000050ee40 RCX: 000000000045cb19 RDX: 0000000000000001 RSI: 0000000020000080 RDI: 0000000000000003 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000d61 R14: 00000000004cb818 R15: 00007fe6ab4226d4 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:4548 1 lock held by in:imklog/5920: #0: (&f->f_pos_lock){+.+.}, at: [] __fdget_pos+0xa6/0xc0 fs/file.c:769 2 locks held by agetty/6004: #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 4 locks held by syz-executor.0/19227: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&tty->atomic_write_lock){+.+.}, at: [] tty_write_lock+0x1d/0x60 drivers/tty/tty_io.c:885 #2: (&tty->termios_rwsem){++++}, at: [] n_tty_write+0x187/0xe20 drivers/tty/n_tty.c:2316 #3: (&ldata->output_lock){+.+.}, at: [] process_output_block drivers/tty/n_tty.c:550 [inline] #3: (&ldata->output_lock){+.+.}, at: [] n_tty_write+0x464/0xe20 drivers/tty/n_tty.c:2333 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1057 Comm: khungtaskd Not tainted 4.14.184-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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 19211 Comm: syz-executor.5 Not tainted 4.14.184-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff88808f7ea680 task.stack: ffff8880534c0000 RIP: 0010:__sanitizer_cov_trace_pc+0x28/0x50 kernel/kcov.c:93 RSP: 0018:ffff8880534c7768 EFLAGS: 00000246 RAX: 0000000000040000 RBX: ffff8880000a0140 RCX: ffffc9000931a000 RDX: 0000000000040000 RSI: ffffffff831c0002 RDI: 0000000000000a00 RBP: ffff8880000a0140 R08: 0000000000000a00 R09: 0000000000000040 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f180a0c2700(0000) GS:ffff8880aed00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f607e0c5800 CR3: 00000000553b3000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: bitfill_aligned drivers/video/fbdev/core/cfbfillrect.c:78 [inline] bitfill_aligned+0x132/0x190 drivers/video/fbdev/core/cfbfillrect.c:35 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 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+0x6c9/0x1220 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+0x46/0xbb RIP: 0033:0x45cb19 RSP: 002b:00007f180a0c1c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004ef680 RCX: 000000000045cb19 RDX: 0000000020000080 RSI: 0000000000004b61 RDI: 0000000000000003 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000582 R14: 00000000004c844c R15: 00007f180a0c26d4 Code: ff ff 90 65 48 8b 04 25 40 ee 01 00 48 85 c0 74 1a 65 8b 15 db 47 a7 7e 81 e2 00 01 1f 00 75 0b 8b 90 58 13 00 00 83 fa 01 74 01 48 8b 34 24 48 8b 88 60 13 00 00 8b 80 5c 13 00 00 48 8b 11