From: Jan Kiszka <jan.kis...@siemens.com> 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 <jan.kis...@siemens.com> --- Changes in v2: - fixed off-by-one in 16-bit limit arch/x86/kvm/emulate.c | 6 +++++- 1 files changed, 5 insertions(+), 1 deletions(-) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 266576c..ab3fff5 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -2355,6 +2355,7 @@ static int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt, u16 old_tss_sel = ops->get_segment_selector(VCPU_SREG_TR, ctxt->vcpu); ulong old_tss_base = get_cached_descriptor_base(ctxt, ops, VCPU_SREG_TR); + u32 desc_limit; /* FIXME: old_tss_base == ~0 ? */ @@ -2375,7 +2376,10 @@ static int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt, } } - if (!next_tss_desc.p || desc_limit_scaled(&next_tss_desc) < 0x67) { + desc_limit = desc_limit_scaled(&next_tss_desc); + if (!next_tss_desc.p || + ((desc_limit < 0x67 && (next_tss_desc.type & 8)) || + desc_limit < 0x2b)) { kvm_queue_exception_e(ctxt->vcpu, TS_VECTOR, tss_selector & 0xfffc); return X86EMUL_PROPAGATE_FAULT; -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html