KVM: x86 emulator: fix memory access during x86 emulation
Currently when x86 emulator needs to access memory, page walk is done with
broadest permission possible, so if emulated instruction was executed
by userspace process it can still access kernel memory. Fix that by
providing correct memory access to page walker during emulation.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index e4e2df3..c44b460 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -616,7 +616,7 @@
if (linear < fc->start || linear >= fc->end) {
size = min(15UL, PAGE_SIZE - offset_in_page(linear));
- rc = ops->read_std(linear, fc->data, size, ctxt->vcpu);
+ rc = ops->fetch(linear, fc->data, size, ctxt->vcpu, NULL);
if (rc)
return rc;
fc->start = linear;
@@ -671,11 +671,11 @@
op_bytes = 3;
*address = 0;
rc = ops->read_std((unsigned long)ptr, (unsigned long *)size, 2,
- ctxt->vcpu);
+ ctxt->vcpu, NULL);
if (rc)
return rc;
rc = ops->read_std((unsigned long)ptr + 2, address, op_bytes,
- ctxt->vcpu);
+ ctxt->vcpu, NULL);
return rc;
}