BUG: kernel NULL pointer dereference, address: 0000000000000007
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 962e2067 P4D 962e2067 PUD 962e3067 PMD 0 
Oops: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 27302 Comm: syz-executor.0 Not tainted 5.9.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:update_pvclock_gtod arch/x86/kvm/x86.c:1749 [inline]
RIP: 0010:pvclock_gtod_notify+0x193/0x570 arch/x86/kvm/x86.c:7452
Code: 43 18 48 8d 7b 1c 48 89 fa 48 c1 ea 03 89 05 6c ea de 0a 48 b8 00 00 00 00 00 fc ff df 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 <38> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
RSP: 0018:ffffc90000da8be8 EFLAGS: 00010002
RAX: 0000000000000007 RBX: ffffffff8c970980 RCX: ffffffff815a14fb
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffff8c97099c
RBP: ffffffff89b35260 R08: 0000000000000000 R09: ffffffff8c5f0a1f
R10: fffffbfff18be143 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: ffffffff89ae9320
FS:  00007ffbee95a700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000007 CR3: 0000000036f66000 CR4: 00000000001526e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 notifier_call_chain+0xb5/0x200 kernel/notifier.c:83
 update_pvclock_gtod kernel/time/timekeeping.c:581 [inline]
 timekeeping_update+0x28a/0x4a0 kernel/time/timekeeping.c:675
 timekeeping_advance+0x6ad/0xa40 kernel/time/timekeeping.c:2122
 tick_do_update_jiffies64.part.0+0x1ec/0x330 kernel/time/tick-sched.c:101
 tick_do_update_jiffies64 kernel/time/tick-sched.c:64 [inline]
 tick_sched_do_timer kernel/time/tick-sched.c:147 [inline]
 tick_sched_timer+0x236/0x2a0 kernel/time/tick-sched.c:1321
 __run_hrtimer kernel/time/hrtimer.c:1524 [inline]
 __hrtimer_run_queues+0x1d5/0xfc0 kernel/time/hrtimer.c:1588
 hrtimer_interrupt+0x32a/0x930 kernel/time/hrtimer.c:1650
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1080 [inline]
 __sysvec_apic_timer_interrupt+0x142/0x5e0 arch/x86/kernel/apic/apic.c:1097
 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:706
 </IRQ>
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline]
 sysvec_apic_timer_interrupt+0xb2/0xf0 arch/x86/kernel/apic/apic.c:1091
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581
RIP: 0010:write_comp_data+0x78/0x80 kernel/kcov.c:242
Code: 00 00 4e 8d 0c dd 28 00 00 00 4c 39 ce 72 1b 49 83 c0 01 4a 89 7c 08 e0 4e 89 54 08 e8 4a 89 54 08 f0 4a 89 4c d8 20 4c 89 00 <c3> 0f 1f 80 00 00 00 00 48 8b 0c 24 40 0f b6 d6 40 0f b6 f7 31 ff
RSP: 0018:ffffc90015967730 EFLAGS: 00000297
RAX: 0000000000000002 RBX: 0000000000000000 RCX: ffffffff83c66546
RDX: 0000000000000000 RSI: ffff888093a70440 RDI: 0000000000000005
RBP: 000000000000000b R08: 000000000000043c R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000010
R13: 0000000000000003 R14: ffff888218bc47f6 R15: 000000000000001c
 slow_imageblit drivers/video/fbdev/core/cfbimgblt.c:173 [inline]
 cfb_imageblit+0x836/0x1010 drivers/video/fbdev/core/cfbimgblt.c:302
 vga_imageblit_expand drivers/video/fbdev/vga16fb.c:1207 [inline]
 vga16fb_imageblit+0x693/0x2210 drivers/video/fbdev/vga16fb.c:1260
 bit_putcs_unaligned drivers/video/fbdev/core/bitblit.c:139 [inline]
 bit_putcs+0x6e1/0xd20 drivers/video/fbdev/core/bitblit.c:188
 fbcon_putcs+0x33c/0x3f0 drivers/video/fbdev/core/fbcon.c:1362
 con_flush drivers/tty/vt/vt.c:2574 [inline]
 vc_con_write_normal drivers/tty/vt/vt.c:2802 [inline]
 do_con_write+0xf8a/0x1d70 drivers/tty/vt/vt.c:2909
 con_write+0x22/0xb0 drivers/tty/vt/vt.c:3249
 process_output_block drivers/tty/n_tty.c:595 [inline]
 n_tty_write+0x3ce/0xf80 drivers/tty/n_tty.c:2333
 do_tty_write drivers/tty/tty_io.c:962 [inline]
 tty_write+0x4d9/0x870 drivers/tty/tty_io.c:1046
 vfs_write+0x2b0/0x730 fs/read_write.c:576
 ksys_write+0x12d/0x250 fs/read_write.c:631
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45d4d9
Code: 5d b4 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 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffbee959c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000038800 RCX: 000000000045d4d9
RDX: 0000000000001006 RSI: 0000000020000080 RDI: 0000000000000004
RBP: 000000000118cf80 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c
R13: 00007ffc0035a85f R14: 00007ffbee95a9c0 R15: 000000000118cf4c
Modules linked in:
CR2: 0000000000000007
---[ end trace 4468ff56263a1f55 ]---
RIP: 0010:update_pvclock_gtod arch/x86/kvm/x86.c:1749 [inline]
RIP: 0010:pvclock_gtod_notify+0x193/0x570 arch/x86/kvm/x86.c:7452
Code: 43 18 48 8d 7b 1c 48 89 fa 48 c1 ea 03 89 05 6c ea de 0a 48 b8 00 00 00 00 00 fc ff df 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 <38> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
RSP: 0018:ffffc90000da8be8 EFLAGS: 00010002
RAX: 0000000000000007 RBX: ffffffff8c970980 RCX: ffffffff815a14fb
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffff8c97099c
RBP: ffffffff89b35260 R08: 0000000000000000 R09: ffffffff8c5f0a1f
R10: fffffbfff18be143 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: ffffffff89ae9320
FS:  00007ffbee95a700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000007 CR3: 0000000036f66000 CR4: 00000000001526e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400