From e8861cfe2c75bdce36655b64d7ce02c2b31b604d Mon Sep 17 00:00:00 2001 From: Jan Kiszka Date: Wed, 14 Apr 2010 16:57:11 +0200 Subject: [PATCH] KVM: x86: Fix TSS size check for 16-bit tasks A 16-bit TSS is only 44 bytes long. So make sure to test for the correct size on task switch. Signed-off-by: Jan Kiszka Signed-off-by: Avi Kivity --- arch/x86/kvm/x86.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 45aa90f8cc57..3c4ca98ad27f 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5126,6 +5126,7 @@ int kvm_task_switch(struct kvm_vcpu *vcpu, u16 tss_selector, int reason) int ret = 0; u32 old_tss_base = get_segment_base(vcpu, VCPU_SREG_TR); u16 old_tss_sel = get_segment_selector(vcpu, VCPU_SREG_TR); + u32 desc_limit; old_tss_base = kvm_mmu_gva_to_gpa_write(vcpu, old_tss_base, NULL); @@ -5148,7 +5149,10 @@ int kvm_task_switch(struct kvm_vcpu *vcpu, u16 tss_selector, int reason) } } - if (!nseg_desc.p || get_desc_limit(&nseg_desc) < 0x67) { + desc_limit = get_desc_limit(&nseg_desc); + if (!nseg_desc.p || + ((desc_limit < 0x67 && (nseg_desc.type & 8)) || + desc_limit < 0x2b)) { kvm_queue_exception_e(vcpu, TS_VECTOR, tss_selector & 0xfffc); return 1; } -- 2.20.1