From 2eedcac8a97cef43c9c5236398fc8c9d0fd9cc0c Mon Sep 17 00:00:00 2001 From: Nadav Amit Date: Mon, 2 Jun 2014 18:34:05 +0300 Subject: [PATCH] KVM: x86: Loading segments on 64-bit mode may be wrong The current emulator implementation ignores the high 32 bits of the base in long-mode. During segment load from the LDT, the base of the LDT is calculated incorrectly and may cause the wrong segment to be loaded. Signed-off-by: Nadav Amit Signed-off-by: Paolo Bonzini --- arch/x86/kvm/emulate.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 136088fb038b..7e4a45cab400 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -1358,17 +1358,19 @@ static void get_descriptor_table_ptr(struct x86_emulate_ctxt *ctxt, u16 selector, struct desc_ptr *dt) { const struct x86_emulate_ops *ops = ctxt->ops; + u32 base3 = 0; if (selector & 1 << 2) { struct desc_struct desc; u16 sel; memset (dt, 0, sizeof *dt); - if (!ops->get_segment(ctxt, &sel, &desc, NULL, VCPU_SREG_LDTR)) + if (!ops->get_segment(ctxt, &sel, &desc, &base3, + VCPU_SREG_LDTR)) return; dt->size = desc_limit_scaled(&desc); /* what if limit > 65535? */ - dt->address = get_desc_base(&desc); + dt->address = get_desc_base(&desc) | ((u64)base3 << 32); } else ops->get_gdt(ctxt, dt); } -- 2.20.1