Re: general protection fault in kvm_lapic_hv_timer_in_use

[syzbot]

syzbot has found a reproducer for the following crash on:

HEAD commit:    234b69e3e089 ocfs2: fix ocfs2 read block panic
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=151d6511400000
kernel config:  https://syzkaller.appspot.com/x/.config?x=5fa12be50bca08d8
dashboard link: https://syzkaller.appspot.com/bug?extid=1c69d94fe42901b029c1
compiler:       gcc (GCC) 8.0.1 20180413 (experimental)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=10e14956400000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+1c69d94fe42901b029c1@xxxxxxxxxxxxxxxxxxxxxxxxx

RBP: 000000000072c040 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000072c04c
R13: 00007ffc0845277f R14: 00007f1c1a1f89c0 R15: 0000000000000002
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
CPU: 1 PID: 5601 Comm: syz-executor0 Not tainted 4.19.0-rc4+ #248
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
RIP: 0010:kvm_lapic_hv_timer_in_use+0x56/0xd0 arch/x86/kvm/lapic.c:1622
Code: c1 ea 03 80 3c 02 00 75 7a 48 8b 9b e0 03 00 00 e8 cf 7a 66 00 48 8d  
7b 7c 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 48  
89 fa 83 e2 07 38 d0 7f 04 84 c0 75 51 0f b6 5b 7c
RSP: 0018:ffff8801b8d0f098 EFLAGS: 00010207
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff810f00fe
RDX: 000000000000000f RSI: ffffffff811859b1 RDI: 000000000000007c
RBP: ffff8801b8d0f0a0 R08: ffff8801d1ea60c0 R09: ffffed00371cfb6c
R10: ffffed00371cfb6c R11: ffff8801b8e7db67 R12: 0000000000000001
R13: 1ffff100371a1e1a R14: 0000000000000000 R15: ffff8801b8e78060
FS:  00007f1c1a1f8700(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f63d064f000 CR3: 00000001c23f2000 CR4: 00000000001426e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 kvm_arch_vcpu_load+0x516/0x970 arch/x86/kvm/x86.c:3128
 kvm_sched_in+0x82/0xa0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3975
 __fire_sched_in_preempt_notifiers kernel/sched/core.c:2481 [inline]
 fire_sched_in_preempt_notifiers kernel/sched/core.c:2487 [inline]
 finish_task_switch+0x56e/0x900 kernel/sched/core.c:2679
 context_switch kernel/sched/core.c:2828 [inline]
 __schedule+0x874/0x1ed0 kernel/sched/core.c:3473
 preempt_schedule_common+0x1f/0xd0 kernel/sched/core.c:3597
 preempt_schedule+0x4d/0x60 kernel/sched/core.c:3623
 ___preempt_schedule+0x16/0x18
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
 _raw_spin_unlock_irqrestore+0xbb/0xd0 kernel/locking/spinlock.c:184
 try_to_wake_up+0x10a/0x12f0 kernel/sched/core.c:2055
 wake_up_process kernel/sched/core.c:2123 [inline]
 wake_up_q+0xa4/0x100 kernel/sched/core.c:441
 futex_wake+0x61f/0x760 kernel/futex.c:1556
 do_futex+0x2e4/0x26d0 kernel/futex.c:3533
 __do_sys_futex kernel/futex.c:3589 [inline]
 __se_sys_futex kernel/futex.c:3557 [inline]
 __x64_sys_futex+0x472/0x6a0 kernel/futex.c:3557
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457679
Code: 1d 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 eb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f1c1a1f7cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 000000000072c048 RCX: 0000000000457679
RDX: 0000000000000016 RSI: 0000000000000081 RDI: 000000000072c04c
RBP: 000000000072c040 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000072c04c
R13: 00007ffc0845277f R14: 00007f1c1a1f89c0 R15: 0000000000000002
Modules linked in:
---[ end trace 107e9054540c67ea ]---
RIP: 0010:kvm_lapic_hv_timer_in_use+0x56/0xd0 arch/x86/kvm/lapic.c:1622
Code: c1 ea 03 80 3c 02 00 75 7a 48 8b 9b e0 03 00 00 e8 cf 7a 66 00 48 8d  
7b 7c 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 48  
89 fa 83 e2 07 38 d0 7f 04 84 c0 75 51 0f b6 5b 7c
RSP: 0018:ffff8801b8d0f098 EFLAGS: 00010207
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff810f00fe
RDX: 000000000000000f RSI: ffffffff811859b1 RDI: 000000000000007c
RBP: ffff8801b8d0f0a0 R08: ffff8801d1ea60c0 R09: ffffed00371cfb6c
R10: ffffed00371cfb6c R11: ffff8801b8e7db67 R12: 0000000000000001
R13: 1ffff100371a1e1a R14: 0000000000000000 R15: ffff8801b8e78060
FS:  00007f1c1a1f8700(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f63d064f000 CR3: 00000001c23f2000 CR4: 00000000001426e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400