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.1:32454 blocked for more than 140 seconds. Not tainted 4.19.118-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28160 32454 6584 0x00000004 Call Trace: schedule+0x8d/0x1b0 kernel/sched/core.c:3559 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3617 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072 fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1457 chrdev_open+0x219/0x5c0 fs/char_dev.c:423 do_dentry_open+0x4a8/0x1160 fs/open.c:796 do_last fs/namei.c:3421 [inline] path_openat+0x1031/0x4200 fs/namei.c:3537 do_filp_open+0x1a1/0x280 fs/namei.c:3567 do_sys_open+0x3c0/0x500 fs/open.c:1085 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c829 Code: 08 48 c7 44 24 10 09 00 00 00 e8 02 a1 fa ff 48 8b 44 24 18 48 8b 4c 24 30 48 83 c1 10 48 89 0c 24 48 89 44 24 08 48 c7 44 24 <10> 58 1f 00 00 e8 dd a0 fa ff 48 8b 44 24 18 48 89 44 24 40 48 8b RSP: 002b:00007f262ef35c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00000000004f7140 RCX: 000000000045c829 RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 000000000000079a R14: 00000000004ca4cf R15: 00007f262ef366d4 Showing all locks held in the system: 1 lock held by khungtaskd/1029: #0: 000000008087e917 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4440 1 lock held by in:imklog/6126: #0: 00000000b965a996 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 fs/file.c:767 2 locks held by syz-executor.0/14480: #0: 000000000166958a (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: 000000008816fe26 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x217/0x1a50 drivers/tty/n_tty.c:2154 3 locks held by syz-executor.1/32448: 1 lock held by syz-executor.1/32454: #0: 000000005c691ff8 (&fb_info->lock){+.+.}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1457 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1029 Comm: khungtaskd Not tainted 4.19.118-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+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1a6/0x1eb lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x962/0xe40 kernel/hung_task.c:287 kthread+0x34a/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 32448 Comm: syz-executor.1 Not tainted 4.19.118-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:vga16fb_fillrect+0x9da/0x1960 drivers/video/fbdev/vga16fb.c:922 Code: ff 89 de 31 ed e8 26 7c ed fd 85 db 4d 89 ec 74 22 e8 aa 7a ed fd 45 88 34 24 83 c5 01 89 df 49 83 c4 01 89 ee e8 86 7b ed fd <39> eb 75 e3 4c 03 6c 24 08 e8 88 7a ed fd 44 89 fe 31 ff 4c 03 2c RSP: 0018:ffff88820c8bf2c8 EFLAGS: 00000297 RAX: 0000000000000002 RBX: 0000000000000050 RCX: ffffffff837a2f0a RDX: 000000000000001d RSI: 0000000000000050 RDI: 0000000000000004 RBP: 000000000000001d R08: ffff88808d2f0300 R09: ffffed10432d1444 R10: ffffed10432d1443 R11: ffff88821968a21f R12: ffff8880000a001d R13: ffff8880000a0000 R14: 0000000000000000 R15: 00000000f013c8b1 FS: 00007f262ef57700(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005599f2824920 CR3: 000000006aaab000 CR4: 00000000001426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: bit_clear_margins+0x2d5/0x4a0 drivers/video/fbdev/core/bitblit.c:232 fbcon_clear_margins+0x2d8/0x370 drivers/video/fbdev/core/fbcon.c:1342 fbcon_switch+0xe0f/0x1970 drivers/video/fbdev/core/fbcon.c:2324 redraw_screen+0x37d/0x870 drivers/tty/vt/vt.c:1009 fbcon_modechanged+0x5eb/0x8f0 drivers/video/fbdev/core/fbcon.c:2972 fbcon_event_notify+0x1b2/0x1d54 drivers/video/fbdev/core/fbcon.c:3347 notifier_call_chain+0xc0/0x230 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+0x85/0xa0 kernel/notifier.c:325 fb_set_var+0xc39/0xe00 drivers/video/fbdev/core/fbmem.c:1042 do_fb_ioctl+0x450/0x9c0 drivers/video/fbdev/core/fbmem.c:1115 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1230 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xcda/0x12e0 fs/ioctl.c:688 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c829 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:00007f262ef56c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004e46c0 RCX: 000000000045c829 RDX: 0000000020000000 RSI: 0000000000004601 RDI: 0000000000000004 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000002f0 R14: 00000000004c5497 R15: 00007f262ef576d4