Re: KASAN: use-after-free Read in do_general_protection

[Paolo Bonzini]

On 26/05/2018 11:29, Dmitry Vyukov wrote:
> KASAN: stack-out-of-bounds Read in do_general_protection
> KASAN: slab-out-of-bounds Read in vmx_vcpu_run
> KASAN: use-after-scope Read in vmx_vcpu_run
> KASAN: stack-out-of-bounds Write in notify_die
> 
> See full info at:
> https://syzkaller.appspot.com/bug?extid=a1264132fc103340628f
> 
> 
> There seems to be 2 problems:
> 
> 1. msr_write_intercepted doing something notoriously bad.

The faulting line is

        msr_bitmap = to_vmx(vcpu)->loaded_vmcs->msr_bitmap;

so I suppose to_vmx(vcpu)->loaded_vmcs is bogus?  That seems like "just"
a corruption of the struct kvm_vcpu, because the loaded_vmcs field is
pointing elsewhere inside the same struct.

Paolo