BUG: unable to handle kernel NULL pointer dereference at 000000000000000f
IP: irq_bypass_register_consumer+0xbe/0x200 virt/lib/irqbypass.c:198
PGD 1fb557067 P4D 1fb557067 PUD 1fb5c6067 PMD 0 
Oops: 0000 [#1] SMP
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 23566 Comm: syz-executor3 Not tainted 4.15.0-rc3-next-20171214+ #67
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:irq_bypass_register_consumer+0xbe/0x200 virt/lib/irqbypass.c:198
RSP: 0018:ffffc9000115fd50 EFLAGS: 00010212
RAX: 0000000000010000 RBX: ffffffffffffffff RCX: ffffffff825a9b5e
RDX: 000000000000008d RSI: ffffc90000fb9000 RDI: 0000000000000000
RBP: ffffc9000115fd70 R08: ffffffff825a9b20 R09: 0000000000000004
R10: ffffc9000115fd40 R11: 0000000000000004 R12: ffff8801fd0a7368
R13: ffff880214133900 R14: ffff8801ff5cd968 R15: ffff88020f5c0000
FS:  00007f6cc346e700(0000) GS:ffff88021fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000000000f CR3: 00000001fc62a004 CR4: 00000000001626f0
DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 kvm_irqfd_assign arch/x86/kvm/../../../virt/kvm/eventfd.c:417 [inline]
 kvm_irqfd+0x6d4/0x860 arch/x86/kvm/../../../virt/kvm/eventfd.c:572
 kvm_vm_ioctl+0x3e2/0x9f0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3000
 vfs_ioctl fs/ioctl.c:46 [inline]
 do_vfs_ioctl+0xaf/0x840 fs/ioctl.c:686
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692
 entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x452a09
RSP: 002b:00007f6cc346dc58 EFLAGS: 00000212 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000071bea0 RCX: 0000000000452a09
RDX: 0000000020c33fe0 RSI: 000000004020ae76 RDI: 0000000000000014
RBP: 0000000000000048 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006ed760
R13: 00000000ffffffff R14: 00007f6cc346e6d4 R15: 0000000000000000
Code: d1 fe 4d 8b 6c 24 10 4d 39 6e 10 74 2f 4d 39 f4 74 2a 4c 89 f3 e8 f3 07 d1 fe 48 8b 1b 48 81 fb 60 e1 19 83 74 43 e8 e2 07 d1 fe <4c> 39 6b 10 0f 94 c2 49 39 dc 0f 94 c0 08 c2 74 d9 e8 cc 07 d1 
RIP: irq_bypass_register_consumer+0xbe/0x200 virt/lib/irqbypass.c:198 RSP: ffffc9000115fd50
CR2: 000000000000000f
---[ end trace 0df3ea3c395b4b15 ]---
Kernel panic - not syncing: Fatal exception
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..