* [PATCH] KVM: nVMX: Trap unconditionally if msr bitmap access fails
@ 2013-02-14 18:46 Jan Kiszka
2013-02-17 8:56 ` Gleb Natapov
0 siblings, 1 reply; 3+ messages in thread
From: Jan Kiszka @ 2013-02-14 18:46 UTC (permalink / raw)
To: Gleb Natapov, Marcelo Tosatti; +Cc: kvm, Nadav Har'El
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(-)
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
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] KVM: nVMX: Trap unconditionally if msr bitmap access fails
2013-02-14 18:46 [PATCH] KVM: nVMX: Trap unconditionally if msr bitmap access fails Jan Kiszka
@ 2013-02-17 8:56 ` Gleb Natapov
2013-02-19 2:20 ` Marcelo Tosatti
0 siblings, 1 reply; 3+ messages in thread
From: Gleb Natapov @ 2013-02-17 8:56 UTC (permalink / raw)
To: Jan Kiszka; +Cc: Marcelo Tosatti, kvm, Nadav Har'El
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.
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] KVM: nVMX: Trap unconditionally if msr bitmap access fails
2013-02-17 8:56 ` Gleb Natapov
@ 2013-02-19 2:20 ` Marcelo Tosatti
0 siblings, 0 replies; 3+ messages in thread
From: Marcelo Tosatti @ 2013-02-19 2:20 UTC (permalink / raw)
To: Gleb Natapov; +Cc: Jan Kiszka, kvm, Nadav Har'El
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.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2013-02-14 18:46 [PATCH] KVM: nVMX: Trap unconditionally if msr bitmap access fails Jan Kiszka
2013-02-17 8:56 ` Gleb Natapov
2013-02-19 2:20 ` Marcelo Tosatti
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