| Message ID | 511D3103.2040005@siemens.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Feb 14, 2013 at 07:46:27PM +0100, Jan Kiszka wrote: > This avoids basing decisions on uninitialized variables, potentially > leaking kernel data to the L1 guest. > > Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Reviewed-by: Gleb Natapov <gleb@redhat.com> > --- > arch/x86/kvm/vmx.c | 3 ++- > 1 files changed, 2 insertions(+), 1 deletions(-) > > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index 2633199..81a25de 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -5991,7 +5991,8 @@ static bool nested_vmx_exit_handled_msr(struct kvm_vcpu *vcpu, > /* Then read the msr_index'th bit from this bitmap: */ > if (msr_index < 1024*8) { > unsigned char b; > - kvm_read_guest(vcpu->kvm, bitmap + msr_index/8, &b, 1); > + if (kvm_read_guest(vcpu->kvm, bitmap + msr_index/8, &b, 1)) > + return 1; > return 1 & (b >> (msr_index & 7)); > } else > return 1; /* let L1 handle the wrong parameter */ > -- > 1.7.3.4 -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sun, Feb 17, 2013 at 10:56:36AM +0200, Gleb Natapov wrote: > On Thu, Feb 14, 2013 at 07:46:27PM +0100, Jan Kiszka wrote: > > This avoids basing decisions on uninitialized variables, potentially > > leaking kernel data to the L1 guest. > > > > Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> > Reviewed-by: Gleb Natapov <gleb@redhat.com> Applied, thanks. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 2633199..81a25de 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -5991,7 +5991,8 @@ static bool nested_vmx_exit_handled_msr(struct kvm_vcpu *vcpu, /* Then read the msr_index'th bit from this bitmap: */ if (msr_index < 1024*8) { unsigned char b; - kvm_read_guest(vcpu->kvm, bitmap + msr_index/8, &b, 1); + if (kvm_read_guest(vcpu->kvm, bitmap + msr_index/8, &b, 1)) + return 1; return 1 & (b >> (msr_index & 7)); } else return 1; /* let L1 handle the wrong parameter */
This avoids basing decisions on uninitialized variables, potentially leaking kernel data to the L1 guest. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> --- arch/x86/kvm/vmx.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-)