INFO: task syz-executor.2:12669 blocked for more than 143 seconds. Not tainted 5.7.0-rc7-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D29600 12669 7191 0x00000004 Call Trace: context_switch kernel/sched/core.c:3367 [inline] __schedule+0x937/0x1ff0 kernel/sched/core.c:4083 schedule+0xd0/0x2a0 kernel/sched/core.c:4158 schedule_timeout+0x55b/0x850 kernel/time/timer.c:1874 __down_common kernel/locking/semaphore.c:220 [inline] __down+0x176/0x2c0 kernel/locking/semaphore.c:237 down+0x57/0x80 kernel/locking/semaphore.c:61 console_lock+0x25/0x80 kernel/printk/printk.c:2314 vt_ioctl+0x1f5f/0x26b0 drivers/tty/vt/vt_ioctl.c:893 tty_ioctl+0xedc/0x1440 drivers/tty/tty_io.c:2656 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0x11a/0x180 fs/ioctl.c:771 __do_sys_ioctl fs/ioctl.c:780 [inline] __se_sys_ioctl fs/ioctl.c:778 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:778 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45ca29 Code: 48 8d 3d 12 57 23 01 e8 f5 22 00 00 eb 98 48 8d 3d 0c 57 23 01 e8 e7 22 00 00 e9 70 ff ff ff 48 8d 3d 1b 57 23 01 e8 d6 22 00 <00> e9 44 ff ff ff 48 8d 3d 02 57 23 01 e8 c5 22 00 00 e9 18 ff ff RSP: 002b:00007f611007ac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004eec80 RCX: 000000000045ca29 RDX: 0000000020000100 RSI: 000000000000560a RDI: 0000000000000004 RBP: 000000000078c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000579 R14: 00000000004c82ca R15: 00007f611007b6d4 Showing all locks held in the system: 1 lock held by khungtaskd/1139: #0: ffffffff899bea80 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5754 1 lock held by in:imklog/6681: #0: ffff88809e87f3b0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:826 1 lock held by syz-executor.2/12640: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1139 Comm: khungtaskd Not tainted 5.7.0-rc7-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+0x188/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x231/0x27e lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xa8c/0x1010 kernel/hung_task.c:289 kthread+0x388/0x470 kernel/kthread.c:268 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:351 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 12640 Comm: syz-executor.2 Not tainted 5.7.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__sanitizer_cov_trace_pc+0x47/0x50 kernel/kcov.c:197 Code: 90 d8 13 00 00 83 fa 02 75 20 48 8b 88 e0 13 00 00 8b 80 dc 13 00 00 48 8b 11 48 83 c2 01 48 39 d0 76 07 48 89 34 d1 48 89 11 0f 1f 84 00 00 00 00 00 65 4c 8b 04 25 00 1f 02 00 65 8b 05 b8 RSP: 0018:ffffc900054d75e8 EFLAGS: 00000246 RAX: 0000000000040000 RBX: 0000000000000000 RCX: ffffc9000d2e1000 RDX: 0000000000040000 RSI: ffffffff83bf72d9 RDI: 0000000000000005 RBP: 0000000000000000 R08: ffff888091b121c0 R09: 0000000000000040 R10: ffff888218ce92df R11: ffffed104319d25b R12: 0000000000000050 R13: ffff8880000a0280 R14: 0000000000000000 R15: 00000000ffffffff FS: 00007f61100bd700(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3ced961000 CR3: 0000000097f19000 CR4: 00000000001426f0 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+0x199/0x200 drivers/video/fbdev/core/cfbfillrect.c:35 cfb_fillrect+0x418/0x7a0 drivers/video/fbdev/core/cfbfillrect.c:327 vga16fb_fillrect+0x68f/0x1960 drivers/video/fbdev/vga16fb.c:951 bit_clear_margins+0x2d5/0x4a0 drivers/video/fbdev/core/bitblit.c:232 fbcon_clear_margins+0x1de/0x240 drivers/video/fbdev/core/fbcon.c:1381 fbcon_switch+0xcde/0x16f0 drivers/video/fbdev/core/fbcon.c:2363 redraw_screen+0x2ae/0x770 drivers/tty/vt/vt.c:1015 vc_do_resize+0xfe6/0x1340 drivers/tty/vt/vt.c:1314 vt_ioctl+0x2062/0x26b0 drivers/tty/vt/vt_ioctl.c:901 tty_ioctl+0xedc/0x1440 drivers/tty/tty_io.c:2656 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0x11a/0x180 fs/ioctl.c:771 __do_sys_ioctl fs/ioctl.c:780 [inline] __se_sys_ioctl fs/ioctl.c:778 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:778 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45ca29 Code: 0d b7 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 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f61100bcc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004eec80 RCX: 000000000045ca29 RDX: 0000000020000100 RSI: 000000000000560a RDI: 0000000000000004 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000579 R14: 00000000004c82ca R15: 00007f61100bd6d4