From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965227AbbA1EZd (ORCPT ); Tue, 27 Jan 2015 23:25:33 -0500 Received: from mail.kernel.org ([198.145.29.136]:41113 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934571AbbA1EZa (ORCPT ); Tue, 27 Jan 2015 23:25:30 -0500 From: lizf@kernel.org To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Nadav Amit , Paolo Bonzini , Zefan Li Subject: [PATCH 3.4 152/177] KVM: x86: Fix uninitialized op->type for some immediate values Date: Wed, 28 Jan 2015 12:10:10 +0800 Message-Id: <1422418236-12852-243-git-send-email-lizf@kernel.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1422418050-12581-1-git-send-email-lizf@kernel.org> References: <1422418050-12581-1-git-send-email-lizf@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Nadav Amit 3.4.106-rc1 review patch. If anyone has any objections, please let me know. ------------------ commit d29b9d7ed76c0b961603ca692b8a562556a20212 upstream. The emulator could reuse an op->type from a previous instruction for some immediate values. If it mistakenly considers the operands as memory operands, it will performs a memory read and overwrite op->val. Consider for instance the ROR instruction - src2 (the number of times) would be read from memory instead of being used as immediate. Mark every immediate operand as such to avoid this problem. Fixes: c44b4c6ab80eef3a9c52c7b3f0c632942e6489aa Signed-off-by: Nadav Amit Signed-off-by: Paolo Bonzini Signed-off-by: Zefan Li --- arch/x86/kvm/emulate.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index e125c3e..0a12507 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -3833,6 +3833,7 @@ static int decode_operand(struct x86_emulate_ctxt *ctxt, struct operand *op, fetch_register_operand(op); break; case OpCL: + op->type = OP_IMM; op->bytes = 1; op->val = ctxt->regs[VCPU_REGS_RCX] & 0xff; break; @@ -3840,6 +3841,7 @@ static int decode_operand(struct x86_emulate_ctxt *ctxt, struct operand *op, rc = decode_imm(ctxt, op, 1, true); break; case OpOne: + op->type = OP_IMM; op->bytes = 1; op->val = 1; break; @@ -3879,21 +3881,27 @@ static int decode_operand(struct x86_emulate_ctxt *ctxt, struct operand *op, ctxt->memop.bytes = ctxt->op_bytes + 2; goto mem_common; case OpES: + op->type = OP_IMM; op->val = VCPU_SREG_ES; break; case OpCS: + op->type = OP_IMM; op->val = VCPU_SREG_CS; break; case OpSS: + op->type = OP_IMM; op->val = VCPU_SREG_SS; break; case OpDS: + op->type = OP_IMM; op->val = VCPU_SREG_DS; break; case OpFS: + op->type = OP_IMM; op->val = VCPU_SREG_FS; break; case OpGS: + op->type = OP_IMM; op->val = VCPU_SREG_GS; break; case OpImplicit: -- 1.9.1