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.5:9051 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.5 D26720 9051 6351 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_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893 fb_open+0xb7/0x400 drivers/video/fbdev/core/fbmem.c:1468 chrdev_open+0x1fc/0x540 fs/char_dev.c:423 do_dentry_open+0x44b/0xec0 fs/open.c:777 vfs_open+0x105/0x220 fs/open.c:888 do_last fs/namei.c:3428 [inline] path_openat+0xb68/0x2aa0 fs/namei.c:3569 do_filp_open+0x18e/0x250 fs/namei.c:3603 do_sys_open+0x292/0x3e0 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x45cba9 RSP: 002b:00007f305e81bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00000000004f9ea0 RCX: 000000000045cba9 RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000007f6 R14: 00000000004cad3c R15: 00007f305e81c6d4 INFO: task syz-executor.3:9073 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.3 D28208 9073 6348 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 vcs_open+0x3d/0x80 drivers/tty/vt/vc_screen.c:599 chrdev_open+0x1fc/0x540 fs/char_dev.c:423 do_dentry_open+0x44b/0xec0 fs/open.c:777 vfs_open+0x105/0x220 fs/open.c:888 do_last fs/namei.c:3428 [inline] path_openat+0xb68/0x2aa0 fs/namei.c:3569 do_filp_open+0x18e/0x250 fs/namei.c:3603 do_sys_open+0x292/0x3e0 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x416921 RSP: 002b:00007fa3f51af7a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 6666666666666667 RCX: 0000000000416921 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007fa3f51af850 RBP: 000000000078bfa0 R08: 000000000000000f R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 00000000ffffffff R13: 0000000000000cad R14: 00000000004cef62 R15: 00007fa3f51b06d4 Showing all locks held in the system: 1 lock held by khungtaskd/1054: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 1 lock held by in:imklog/5987: #0: (&f->f_pos_lock){+.+.}, at: [] __fdget_pos+0xa6/0xc0 fs/file.c:769 1 lock held by syz-executor.5/9051: #0: (&fb_info->lock){+.+.}, at: [] fb_open+0xb7/0x400 drivers/video/fbdev/core/fbmem.c:1468 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1054 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 9053 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: ffff8880a5b060c0 task.stack: ffff888056250000 RIP: 0010:deref_stack_reg+0x17/0xc0 arch/x86/kernel/unwind_orc.c:292 RSP: 0018:ffff8880aec077e8 EFLAGS: 00000282 RAX: 0000000000000000 RBX: 1ffff11015d80f08 RCX: ffffffff8930294e RDX: 0000000000000008 RSI: ffff8880aec07ff8 RDI: ffff8880aec078b8 RBP: 0000000000000002 R08: ffffffff89302952 R09: 0000000000000001 R10: 000000000011d2cc R11: 0000000000056071 R12: ffff8880aec07860 R13: dffffc0000000000 R14: ffff8880aec07908 R15: ffff8880aec078b8 FS: 00007f305e7fb700(0000) GS:ffff8880aec00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4bc1608d84 CR3: 0000000092168000 CR4: 00000000001426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: unwind_next_frame+0x6e4/0x1700 arch/x86/kernel/unwind_orc.c:420 __save_stack_trace+0x6b/0xd0 arch/x86/kernel/stacktrace.c:44 save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc.part.0+0x4f/0xd0 mm/kasan/kasan.c:551 kmem_cache_alloc_node+0x146/0x400 mm/slab.c:3642 __alloc_skb+0x9a/0x4c0 net/core/skbuff.c:193 alloc_skb include/linux/skbuff.h:980 [inline] ndisc_alloc_skb+0x134/0x310 net/ipv6/ndisc.c:402 ndisc_send_rs+0x2ec/0x630 net/ipv6/ndisc.c:661 addrconf_rs_timer+0x280/0x5a0 net/ipv6/addrconf.c:3765 call_timer_fn+0x14a/0x650 kernel/time/timer.c:1279 expire_timers+0x233/0x4d0 kernel/time/timer.c:1318 __run_timers kernel/time/timer.c:1636 [inline] run_timer_softirq+0x1d8/0x5b0 kernel/time/timer.c:1649 __do_softirq+0x254/0x9bf kernel/softirq.c:288 invoke_softirq kernel/softirq.c:368 [inline] irq_exit+0x15b/0x1a0 kernel/softirq.c:409 exiting_irq arch/x86/include/asm/apic.h:648 [inline] smp_apic_timer_interrupt+0x141/0x5f0 arch/x86/kernel/apic/apic.c:1102 apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:793 RIP: 0010:__sanitizer_cov_trace_pc+0x3d/0x50 kernel/kcov.c:87 RSP: 0018:ffff8880562573d8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff10 RAX: 0000000000040000 RBX: ffff8880000a0050 RCX: ffffc9000d491000 RDX: 000000000003ffff RSI: ffffffff831f9ef3 RDI: ffff888056257490 RBP: 0000000000000050 R08: 000000000000ffff R09: ffffed1014bc51d4 R10: ffffed1014bc51d3 R11: ffff8880a5e28e9f R12: ffff8880000a0024 R13: 0000000000000000 R14: 00000000d50a9390 R15: 000000000000004f 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+0x274/0x300 drivers/video/fbdev/core/fbcon.c:1320 fbcon_switch+0xc4e/0x1700 drivers/video/fbdev/core/fbcon.c:2302 redraw_screen+0x332/0x760 drivers/tty/vt/vt.c:689 fbcon_modechanged+0x552/0x800 drivers/video/fbdev/core/fbcon.c:2949 fbcon_event_notify+0x11a/0x1750 drivers/video/fbdev/core/fbcon.c:3302 notifier_call_chain+0x107/0x1a0 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+0x79/0x90 kernel/notifier.c:325 fb_set_var+0xaad/0xc70 drivers/video/fbdev/core/fbmem.c:1054 do_fb_ioctl+0x3cc/0x840 drivers/video/fbdev/core/fbmem.c:1127 fb_ioctl+0xda/0x120 drivers/video/fbdev/core/fbmem.c:1242 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: 0033:0x45cba9 RSP: 002b:00007f305e7fac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004e6560 RCX: 000000000045cba9 RDX: 0000000020000000 RSI: 0000000000004601 RDI: 0000000000000008 RBP: 000000000078c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000311 R14: 00000000004c59ee R15: 00007f305e7fb6d4 Code: eb de 66 90 48 8b 07 48 89 06 c3 66 0f 1f 84 00 00 00 00 00 41 55 49 bd 00 00 00 00 00 fc ff df 41 54 49 89 d4 ba 08 00 00 00 55 <48> 89 f5 53 48 83 ec 40 48 89 e3 48 c7 04 24 b3 8a b5 41 48 c7