kobject: 'lo' (000000004db6931b): kobject_uevent_env kobject: 'lo' (000000004db6931b): kobject_uevent_env: uevent_suppress caused the event to drop! kobject: 'lo' (000000004db6931b): calling ktype release kobject: 'lo': free name INFO: task syz-executor.5:6676 blocked for more than 140 seconds. Not tainted 4.16.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D29288 6676 6636 0x00000004 Call Trace: context_switch kernel/sched/core.c:2857 [inline] __schedule+0x798/0x1f10 kernel/sched/core.c:3435 schedule+0x7f/0x1b0 kernel/sched/core.c:3494 schedule_timeout+0x6f0/0xe00 kernel/time/timer.c:1777 __down_common kernel/locking/semaphore.c:221 [inline] __down+0x180/0x2b0 kernel/locking/semaphore.c:238 down+0x5e/0x80 kernel/locking/semaphore.c:62 console_lock+0x23/0x70 kernel/printk/printk.c:2211 do_fb_ioctl+0x3fa/0x940 drivers/video/fbdev/core/fbmem.c:1114 fb_ioctl+0xcb/0x150 drivers/video/fbdev/core/fbmem.c:1235 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x196/0xff0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x74/0x80 fs/ioctl.c:692 do_syscall_64+0x1c9/0x6a0 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x26/0x9b RIP: 0033:0x45a919 RSP: 002b:00007f3e472fcc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a919 RDX: 0000000020000000 RSI: 0000000000004601 RDI: 0000000000000003 RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f3e472fd6d4 R13: 00000000004c310d R14: 00000000004d8498 R15: 00000000ffffffff Showing all locks held in the system: 2 locks held by khungtaskd/1040: #0: (rcu_read_lock){....}, at: [<000000001ae45ed5>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [<000000001ae45ed5>] watchdog+0xfc/0x8d0 kernel/hung_task.c:249 #1: (tasklist_lock){.+.+}, at: [<0000000056f59066>] debug_show_all_locks+0x79/0x222 kernel/locking/lockdep.c:4470 1 lock held by rsyslogd/6422: #0: (&f->f_pos_lock){+.+.}, at: [<0000000024160c64>] __fdget_pos+0x8e/0xc0 fs/file.c:765 2 locks held by getty/6512: #0: (&tty->ldisc_sem){++++}, at: [<00000000c1980b1e>] ldsem_down_read+0x2d/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000bfc71959>] n_tty_read+0x1ee/0x16c0 drivers/tty/n_tty.c:2131 2 locks held by getty/6513: #0: (&tty->ldisc_sem){++++}, at: [<00000000c1980b1e>] ldsem_down_read+0x2d/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000bfc71959>] n_tty_read+0x1ee/0x16c0 drivers/tty/n_tty.c:2131 2 locks held by getty/6514: #0: (&tty->ldisc_sem){++++}, at: [<00000000c1980b1e>] ldsem_down_read+0x2d/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000bfc71959>] n_tty_read+0x1ee/0x16c0 drivers/tty/n_tty.c:2131 2 locks held by getty/6515: #0: (&tty->ldisc_sem){++++}, at: [<00000000c1980b1e>] ldsem_down_read+0x2d/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000bfc71959>] n_tty_read+0x1ee/0x16c0 drivers/tty/n_tty.c:2131 2 locks held by getty/6516: #0: (&tty->ldisc_sem){++++}, at: [<00000000c1980b1e>] ldsem_down_read+0x2d/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000bfc71959>] n_tty_read+0x1ee/0x16c0 drivers/tty/n_tty.c:2131 2 locks held by getty/6517: #0: (&tty->ldisc_sem){++++}, at: [<00000000c1980b1e>] ldsem_down_read+0x2d/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000bfc71959>] n_tty_read+0x1ee/0x16c0 drivers/tty/n_tty.c:2131 2 locks held by getty/6518: #0: (&tty->ldisc_sem){++++}, at: [<00000000c1980b1e>] ldsem_down_read+0x2d/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000bfc71959>] n_tty_read+0x1ee/0x16c0 drivers/tty/n_tty.c:2131 1 lock held by syz-executor.4/6677: #0: (&fb_info->lock){+.+.}, at: [<00000000fd961c7a>] fb_release+0x4d/0x140 drivers/video/fbdev/core/fbmem.c:1490 1 lock held by syz-executor.1/6682: #0: (&fb_info->lock){+.+.}, at: [<00000000fd961c7a>] fb_release+0x4d/0x140 drivers/video/fbdev/core/fbmem.c:1490 1 lock held by syz-executor.0/6714: #0: (&fb_info->lock){+.+.}, at: [<0000000055e728ee>] fb_open+0x9f/0x390 drivers/video/fbdev/core/fbmem.c:1461 1 lock held by syz-executor.0/6718: #0: (&fb_info->lock){+.+.}, at: [<0000000055e728ee>] fb_open+0x9f/0x390 drivers/video/fbdev/core/fbmem.c:1461 1 lock held by syz-executor.3/6717: #0: (&fb_info->lock){+.+.}, at: [<0000000055e728ee>] fb_open+0x9f/0x390 drivers/video/fbdev/core/fbmem.c:1461 1 lock held by syz-executor.3/6719: #0: (&fb_info->lock){+.+.}, at: [<0000000055e728ee>] fb_open+0x9f/0x390 drivers/video/fbdev/core/fbmem.c:1461 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1040 Comm: khungtaskd Not tainted 4.16.0-rc1-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+0xed/0x131 lib/dump_stack.c:53 nmi_cpu_backtrace.cold.5+0x13/0xb2 lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0xf4/0x118 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:138 [inline] check_hung_task kernel/hung_task.c:132 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:190 [inline] watchdog+0x5a8/0x8d0 kernel/hung_task.c:249 kthread+0x316/0x3d0 kernel/kthread.c:238 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:429 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 6652 Comm: syz-executor.2 Not tainted 4.16.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:bitfill_aligned+0x30/0x120 drivers/video/fbdev/core/cfbfillrect.c:44 RSP: 0018:ffff880088387140 EFLAGS: 00000246 RAX: 0000000000000028 RBX: 0000000000000a00 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff8800000a0000 RDI: 0000000000000000 RBP: ffff880088387150 R08: 0000000000000a00 R09: 0000000000000040 R10: ffffffffffffffff R11: 0000000000000000 R12: ffffffffffffffff R13: ffff8800a5e22c40 R14: 00000000698037fc R15: ffffed0014bc45c4 FS: 00007f0a9bf79700(0000) GS:ffff8800aed00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000a78030 CR3: 000000009797a000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: cfb_fillrect+0x3e8/0x750 drivers/video/fbdev/core/cfbfillrect.c:327 vga16fb_fillrect+0x5ac/0x19b0 drivers/video/fbdev/vga16fb.c:951 bit_clear_margins+0x392/0x610 drivers/video/fbdev/core/bitblit.c:232 fbcon_clear_margins+0x1b1/0x330 drivers/video/fbdev/core/fbcon.c:1324 fbcon_switch+0xbe9/0x1982 drivers/video/fbdev/core/fbcon.c:2306 redraw_screen+0x313/0x810 drivers/tty/vt/vt.c:690 fbcon_modechanged+0x56f/0x890 drivers/video/fbdev/core/fbcon.c:2953 fbcon_event_notify+0xcc/0x1980 drivers/video/fbdev/core/fbcon.c:3306 notifier_call_chain+0x8a/0x160 kernel/notifier.c:93 __blocking_notifier_call_chain kernel/notifier.c:317 [inline] blocking_notifier_call_chain+0x6b/0xa0 kernel/notifier.c:328 fb_notifier_call_chain+0x16/0x20 drivers/video/fbdev/core/fb_notify.c:45 fb_set_var+0xadd/0xf60 drivers/video/fbdev/core/fbmem.c:1047 do_fb_ioctl+0x44c/0x940 drivers/video/fbdev/core/fbmem.c:1120 fb_ioctl+0xcb/0x150 drivers/video/fbdev/core/fbmem.c:1235 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x196/0xff0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x74/0x80 fs/ioctl.c:692 do_syscall_64+0x1c9/0x6a0 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x26/0x9b RIP: 0033:0x45a919 RSP: 002b:00007f0a9bf78c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a919 RDX: 0000000020000000 RSI: 0000000000004601 RDI: 0000000000000003 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f0a9bf796d4 R13: 00000000004c310d R14: 00000000004d8498 R15: 00000000ffffffff Code: e2 00 00 00 55 41 89 d3 48 89 cf 89 d1 48 89 e5 41 54 49 c7 c2 ff ff ff ff 53 42 8d 1c 02 31 d2 4d 89 d4 89 d8 49 d3 e4 41 f7 f1 <89> d1 49 d3 e2 44 39 cb 49 f7 d2 77 21 4c 89 e0 4c 21 d0 4d 85