Re: WARNING in kvm_arch_vcpu_ioctl_run (2)

[Dmitry Vyukov]

On Mon, Nov 20, 2017 at 10:19 AM, Wanpeng Li <kernellwp@xxxxxxxxx> wrote:
> Hi Dmitry,
> 2017-11-20 12:09 GMT+08:00 Wanpeng Li <kernellwp@xxxxxxxxx>:
>> 2017-11-18 4:22 GMT+08:00 syzbot
>> <bot+d9fbc5c299aa8a95ac07572b4f6e191c0f4efff6@xxxxxxxxxxxxxxxxxxxxxxxxx>:
>>> Hello,
>>>
>>> syzbot has tested the proposed patch but the reproducer still triggered
>>> crash:
>>> WARNING in kvm_arch_vcpu_ioctl_run
>>>
>>> VMExit: intr_info=00000000 errcode=00000000 ilen=00000000
>>>         reason=80000021 qualification=0000000000000000
>>> IDTVectoring: info=00000000 errcode=00000000
>>> TSC Offset = 0xffffffeeb46bc6ac
>>> EPT pointer = 0x00000001ce37601e
>>> WARNING: CPU: 0 PID: 3023 at arch/x86/kvm/x86.c:7293
>>> kvm_arch_vcpu_ioctl_run+0x213/0x5d20
>>> Kernel panic - not syncing: panic_on_warn set ...
>>>
>>> CPU: 0 PID: 3023 Comm: syz-executor4 Not tainted 4.14.0-next-20171117+ #9
>>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
>>> Google 01/01/2011
>>> Call Trace:
>>>  dump_stack+0x173/0x237
>>>  panic+0x1e4/0x41c
>>>  __warn+0x1d9/0x1f0
>>>  report_bug+0x20a/0x2d0
>>>  fixup_bug.part.10+0x32/0x80
>>>  do_error_trap+0x29c/0x370
>>>  invalid_op+0x18/0x20
>>> RIP: 0010:kvm_arch_vcpu_ioctl_run+0x213/0x5d20
>>> RSP: 0018:ffff8801ce197680 EFLAGS: 00010293
>>> RAX: ffff8801ce588440 RBX: ffff8801d5b8f000 RCX: ffffffff810d4003
>>> RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8801ce0e02b8
>>> RBP: ffff8801ce197a50 R08: 0000000000000001 R09: 0000000000000001
>>> R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
>>> R13: ffff8801ce0e0168 R14: ffff8801cec10980 R15: ffff8801ce0e0080
>>>  kvm_vcpu_ioctl+0x619/0xf80
>>>  do_vfs_ioctl+0x18b/0x13e0
>>>  SyS_ioctl+0x7e/0xb0
>>>  entry_SYSCALL_64_fastpath+0x1f/0x96
>>> RIP: 0033:0x452879
>>> RSP: 002b:00007f4bc97fdbe8 EFLAGS: 00000212 ORIG_RAX: 0000000000000010
>>> RAX: ffffffffffffffda RBX: 0000000000000082 RCX: 0000000000452879
>>> RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000004
>>> RBP: 00007ffce1993510 R08: 0000000000000000 R09: 0000000000000000
>>> R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000000
>>> R13: 00007ffce199348f R14: 00007f4bc97fe9c0 R15: 0000000000000006
>>> Dumping ftrace buffer:
>>>    (ftrace buffer empty)
>>> Kernel Offset: disabled
>>> Rebooting in 86400 seconds..
>>
>> I will have a look.
>
> Please have a try. https://lkml.org/lkml/2017/11/20/118

Hi Wanpeng,

There is shiny new feature being rolled for syzbot, see "#syz test" here:

https://github.com/google/syzkaller/blob/master/docs/syzbot.md#communication-with-syzbot

Please have a try ;)