general protection fault in synic_get

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    a99163e9 Merge tag 'devicetree-for-5.12' of git://git.kern..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11564f12d00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=49116074dd53b631
dashboard link: https://syzkaller.appspot.com/bug?extid=0182764296ab74754c77
compiler:       Debian clang version 11.0.1-2

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0182764296ab74754c77@xxxxxxxxxxxxxxxxxxxxxxxxx

general protection fault, probably for non-canonical address 0xdffffc0000000028: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000140-0x0000000000000147]
CPU: 0 PID: 13202 Comm: syz-executor.2 Not tainted 5.11.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:synic_get+0x37f/0x450 arch/x86/kvm/hyperv.c:165
Code: 74 08 48 89 ef e8 e1 d7 a4 00 48 8b 6d 00 48 8d 5d 20 48 81 c5 40 01 00 00 48 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <8a> 04 08 84 c0 0f 85 8b 00 00 00 0f b6 6d 00 45 31 f6 31 ff 89 ee
RSP: 0018:ffffc90002937be0 EFLAGS: 00010206
RAX: 0000000000000028 RBX: 0000000000000020 RCX: dffffc0000000000
RDX: ffffc9000d3e8000 RSI: 000000000000122d RDI: 000000000000122e
RBP: 0000000000000140 R08: ffffffff81177c28 R09: fffff5200052133e
R10: fffff5200052133e R11: 0000000000000000 R12: ffff888013658028
R13: ffffc900029099e8 R14: 1ffff9200052133d R15: 0000000000000000
FS:  00007f9eefe5e700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000053e038 CR3: 0000000064691000 CR4: 00000000001526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 kvm_hv_synic_set_irq+0x31/0x300 arch/x86/kvm/hyperv.c:452
 kvm_set_irq+0x159/0x260 arch/x86/kvm/../../../virt/kvm/irqchip.c:89
 kvm_vm_ioctl_irq_line+0x8d/0x130 arch/x86/kvm/x86.c:5230
 kvm_vm_ioctl+0x729/0x2c40 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3918
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:739
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x465ef9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f9eefe5e188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000056c008 RCX: 0000000000465ef9
RDX: 0000000020000000 RSI: 00000000c008ae67 RDI: 0000000000000004
RBP: 00000000004bcd1c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c008
R13: 00007ffe57cd4f8f R14: 00007f9eefe5e300 R15: 0000000000022000
Modules linked in:
---[ end trace f15602d881a9aa88 ]---
RIP: 0010:synic_get+0x37f/0x450 arch/x86/kvm/hyperv.c:165
Code: 74 08 48 89 ef e8 e1 d7 a4 00 48 8b 6d 00 48 8d 5d 20 48 81 c5 40 01 00 00 48 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <8a> 04 08 84 c0 0f 85 8b 00 00 00 0f b6 6d 00 45 31 f6 31 ff 89 ee
RSP: 0018:ffffc90002937be0 EFLAGS: 00010206
RAX: 0000000000000028 RBX: 0000000000000020 RCX: dffffc0000000000
RDX: ffffc9000d3e8000 RSI: 000000000000122d RDI: 000000000000122e
RBP: 0000000000000140 R08: ffffffff81177c28 R09: fffff5200052133e
R10: fffff5200052133e R11: 0000000000000000 R12: ffff888013658028
R13: ffffc900029099e8 R14: 1ffff9200052133d R15: 0000000000000000
FS:  00007f9eefe5e700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a3cceb4a38 CR3: 0000000064691000 CR4: 00000000001526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.