Re: WARNING in x86_emulate_insn

[Wanpeng Li]

2017-12-08 11:22 GMT+08:00 syzbot
<bot+75375385991b4f8c599704a10849863c586ea284@xxxxxxxxxxxxxxxxxxxxxxxxx>:
> syzkaller has found reproducer for the following crash on
> 968edbd93c0cbb40ab48aca972392d377713a0c3
> git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/master
> compiler: gcc (GCC) 7.1.1 20170620
> .config is attached
> Raw console output is attached.
> C reproducer is attached
> syzkaller reproducer is attached. See https://goo.gl/kgGztJ
> for information about syzkaller reproducers
>

I will have a look.

Regards,
Wanpeng Li

>
> kvm: KVM_SET_TSS_ADDR need to be called before entering vcpu
> WARNING: CPU: 0 PID: 3153 at arch/x86/kvm/emulate.c:5654
> x86_emulate_insn+0xd01/0x3cf0 arch/x86/kvm/emulate.c:5654
> Kernel panic - not syncing: panic_on_warn set ...
>
> CPU: 0 PID: 3153 Comm: syzkaller990902 Not tainted 4.15.0-rc2+ #212
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> Google 01/01/2011
> Call Trace:
>  __dump_stack lib/dump_stack.c:17 [inline]
>  dump_stack+0x194/0x257 lib/dump_stack.c:53
>  panic+0x1e4/0x41c kernel/panic.c:183
>  __warn+0x1dc/0x200 kernel/panic.c:547
>  report_bug+0x211/0x2d0 lib/bug.c:184
>  fixup_bug.part.11+0x37/0x80 arch/x86/kernel/traps.c:177
>  fixup_bug arch/x86/kernel/traps.c:246 [inline]
>  do_error_trap+0x2d7/0x3e0 arch/x86/kernel/traps.c:295
>  do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:314
>  invalid_op+0x18/0x20 arch/x86/entry/entry_64.S:930
> RIP: 0010:x86_emulate_insn+0xd01/0x3cf0 arch/x86/kvm/emulate.c:5654
> RSP: 0018:ffff8801c56f7300 EFLAGS: 00010293
> RAX: ffff8801c62d2080 RBX: 1ffff10038adee69 RCX: ffffffff81154231
> RDX: 0000000000000000 RSI: ffffffffffffffff RDI: ffff8801c55da888
> RBP: ffff8801c56f7410 R08: ffff8801c55d8040 R09: ffffffff85224dc0
> R10: 0000000000000002 R11: ffffed0038abb551 R12: 00000000000000ff
> R13: ffff8801c55da860 R14: 0000000000000002 R15: ffff8801c55da983
>  x86_emulate_instruction+0x411/0x1ad0 arch/x86/kvm/x86.c:5769
>  emulate_instruction arch/x86/include/asm/kvm_host.h:1164 [inline]
>  handle_invalid_guest_state arch/x86/kvm/vmx.c:6606 [inline]
>  vmx_handle_exit+0x6e3/0x1ce0 arch/x86/kvm/vmx.c:8826
>  vcpu_enter_guest arch/x86/kvm/x86.c:7082 [inline]
>  vcpu_run arch/x86/kvm/x86.c:7144 [inline]
>  kvm_arch_vcpu_ioctl_run+0x1cb4/0x5c60 arch/x86/kvm/x86.c:7312
>  kvm_vcpu_ioctl+0x64c/0x1010 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2574
>  vfs_ioctl fs/ioctl.c:46 [inline]
>  do_vfs_ioctl+0x1b1/0x1530 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: 0033:0x4402e9
> RSP: 002b:00007ffde2bdf2c8 EFLAGS: 00000217 ORIG_RAX: 0000000000000010
> RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 00000000004402e9
> RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005
> RBP: 00000000006ca018 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000217 R12: 0000000000401c50
> R13: 0000000000401ce0 R14: 0000000000000000 R15: 0000000000000000
>
> Dumping ftrace buffer:
>    (ftrace buffer empty)
> Kernel Offset: disabled
> Rebooting in 86400 seconds..
>