INFO: trying to register non-static key.
the code is fine but needs lockdep annotation.
turning off the locking correctness validator.
CPU: 0 PID: 10489 Comm: syz-executor.2 Not tainted 4.14.172-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x13e/0x194 lib/dump_stack.c:58
 register_lock_class+0x2fe/0x1600 kernel/locking/lockdep.c:768
 __lock_acquire+0x147/0x4620 kernel/locking/lockdep.c:3374
 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3994
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x8c/0xbf kernel/locking/spinlock.c:160
 try_to_wake_up+0x6a/0xef0 kernel/sched/core.c:1997
 wake_up_worker kernel/workqueue.c:840 [inline]
 insert_work+0x238/0x2f0 kernel/workqueue.c:1313
 __queue_work+0x408/0xf10 kernel/workqueue.c:1463
 call_timer_fn+0x14a/0x650 kernel/time/timer.c:1279
 expire_timers kernel/time/timer.c:1314 [inline]
 __run_timers kernel/time/timer.c:1636 [inline]
 __run_timers kernel/time/timer.c:1604 [inline]
 run_timer_softirq+0x369/0x1390 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+0x141/0x5e0 arch/x86/kernel/apic/apic.c:1102
 apic_timer_interrupt+0x8f/0xa0 arch/x86/entry/entry_64.S:792
 </IRQ>
RIP: 0010:fast_imageblit drivers/video/fbdev/core/cfbimgblt.c:258 [inline]
RIP: 0010:cfb_imageblit+0x564/0xea0 drivers/video/fbdev/core/cfbimgblt.c:300
RSP: 0018:ffff88820bf4f2c0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff10
RAX: 0000000000000000 RBX: ffff88821922d4e1 RCX: 0000000000000000
RDX: 000000000003843f RSI: 0000000000000000 RDI: ffffffff86e86120
RBP: ffff888000179fc8 R08: ffff88821922d4ef R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
R13: ffff888000179fc8 R14: 0000000000000000 R15: ffff888000179fc4
 vga_imageblit_expand drivers/video/fbdev/vga16fb.c:1208 [inline]
 vga16fb_imageblit+0x61f/0x2160 drivers/video/fbdev/vga16fb.c:1261
 soft_cursor+0x50d/0xa40 drivers/video/fbdev/core/softcursor.c:74
 bit_cursor+0x10d9/0x1700 drivers/video/fbdev/core/bitblit.c:386
 fbcon_cursor+0x4be/0x690 drivers/video/fbdev/core/fbcon.c:1347
 set_cursor drivers/tty/vt/vt.c:602 [inline]
 set_cursor+0x1aa/0x220 drivers/tty/vt/vt.c:593
 con_flush_chars drivers/tty/vt/vt.c:2867 [inline]
 con_flush_chars drivers/tty/vt/vt.c:2856 [inline]
 con_write+0x97/0xc0 drivers/tty/vt/vt.c:2788
 process_output_block drivers/tty/n_tty.c:595 [inline]
 n_tty_write+0x375/0xe30 drivers/tty/n_tty.c:2333
 do_tty_write drivers/tty/tty_io.c:959 [inline]
 tty_write+0x3f0/0x700 drivers/tty/tty_io.c:1043
 __vfs_write+0xe4/0x630 fs/read_write.c:480
 __kernel_write+0xf5/0x330 fs/read_write.c:501
 write_pipe_buf+0x143/0x1b0 fs/splice.c:797
 splice_from_pipe_feed fs/splice.c:502 [inline]
 __splice_from_pipe+0x332/0x740 fs/splice.c:626
 splice_from_pipe+0xc6/0x120 fs/splice.c:661
 default_file_splice_write+0x37/0x80 fs/splice.c:809
 do_splice_from fs/splice.c:851 [inline]
 direct_splice_actor+0x115/0x160 fs/splice.c:1018
 splice_direct_to_actor+0x27e/0x730 fs/splice.c:973
 do_splice_direct+0x164/0x210 fs/splice.c:1061
 do_sendfile+0x469/0xaf0 fs/read_write.c:1441
 SYSC_sendfile64 fs/read_write.c:1502 [inline]
 SyS_sendfile64+0xff/0x110 fs/read_write.c:1488
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45c479
RSP: 002b:00007f55dfcdec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f55dfcdf6d4 RCX: 000000000045c479
RDX: 0000000000000000 RSI: 000000000000000a RDI: 000000000000000b
RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000081 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000008d1 R14: 00000000004cb364 R15: 000000000076bf2c
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 1 PID: 10466 Comm: syz-executor.5 Not tainted 4.14.172-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff88803694a140 task.stack: ffff88820bea0000
RIP: 0010:__read_once_size include/linux/compiler.h:183 [inline]
RIP: 0010:mm_update_next_owner+0x367/0x5b0 kernel/exit.c:451
RSP: 0018:ffff88820bea7aa0 EFLAGS: 00010202
RAX: 0000000000000002 RBX: dffffc0000000000 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000100 RDI: ffff8880001789c0
RBP: 0000000000000000 R08: ffff8880a7d5e630 R09: 0000000000000000
R10: ffff88820bea7ac8 R11: ffff88803694a140 R12: ffff8880a04d2d00
R13: 0000000000000010 R14: ffff88803694a140 R15: ffff888052f7c040
FS:  0000000000000000(0000) GS:ffff8880aeb00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32124000 CR3: 000000004cc2f000 CR4: 00000000001426e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 exit_mm kernel/exit.c:544 [inline]
 do_exit+0x92b/0x2b00 kernel/exit.c:845
 do_group_exit+0x100/0x310 kernel/exit.c:955
 get_signal+0x385/0x1ca0 kernel/signal.c:2418
 do_signal+0x7c/0x1690 arch/x86/kernel/signal.c:814
 exit_to_usermode_loop+0x159/0x220 arch/x86/entry/common.c:160
 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:270 [inline]
 do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45c479
RSP: 002b:00007ffd2de69a38 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffdfc RBX: 00000000000003e8 RCX: 000000000045c479
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000076bfcc
RBP: 000000000000002d R08: 01ffffffffffffff R09: 01ffffffffffffff
R10: 00007ffd2de69b10 R11: 0000000000000246 R12: 000000000076bfc0
R13: 00000000000fbeaf R14: 00000000000fbedc R15: 000000000076bfcc
Code: 00 48 8d bd 20 03 00 00 48 89 f8 48 c1 e8 03 80 3c 18 00 0f 85 fb 01 00 00 48 8b ad 20 03 00 00 4c 8d 6d 10 4c 89 e8 48 c1 e8 03 <80> 3c 18 00 0f 85 d2 01 00 00 48 8b 45 10 48 8d a8 68 fa ff ff 
RIP: __read_once_size include/linux/compiler.h:183 [inline] RSP: ffff88820bea7aa0
RIP: mm_update_next_owner+0x367/0x5b0 kernel/exit.c:451 RSP: ffff88820bea7aa0
---[ end trace 5088ec8b26f0602b ]---