From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754651AbaIHRs2 (ORCPT ); Mon, 8 Sep 2014 13:48:28 -0400 Received: from out4-smtp.messagingengine.com ([66.111.4.28]:40047 "EHLO out4-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753781AbaIHRr4 (ORCPT ); Mon, 8 Sep 2014 13:47:56 -0400 X-Sasl-enc: EZYxsx7MYWkx6wI+ODtLJPELBROarOk9Hyh/hjY1arAS 1410197886 From: Henrique de Moraes Holschuh To: linux-kernel@vger.kernel.org Cc: Borislav Petkov , H Peter Anvin Subject: [PATCH 8/8] x86, microcode, intel: defend apply_microcode_intel with BUG_ON Date: Mon, 8 Sep 2014 14:37:54 -0300 Message-Id: <1410197875-19252-9-git-send-email-hmh@hmh.eng.br> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1410197875-19252-1-git-send-email-hmh@hmh.eng.br> References: <1410197875-19252-1-git-send-email-hmh@hmh.eng.br> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Microcode updates that requires an unknown loader should never reach the apply_* functions (the code should have rejected it earlier). Likewise for an unknown microcode header layout. Signed-off-by: Henrique de Moraes Holschuh --- arch/x86/kernel/cpu/microcode/intel.c | 2 ++ arch/x86/kernel/cpu/microcode/intel_early.c | 2 ++ 2 files changed, 4 insertions(+) diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c index 40caef1..439681f 100644 --- a/arch/x86/kernel/cpu/microcode/intel.c +++ b/arch/x86/kernel/cpu/microcode/intel.c @@ -157,6 +157,8 @@ static int apply_microcode_intel(int cpu) if (mc_intel == NULL) return 0; + BUG_ON(mc_intel->hdr.hdrver != 1 || mc_intel->hdr.ldrver != 1); + /* Intel SDM vol 3A section 9.11.6, page 9-34 */ if (WARN_ONCE((unsigned long)(mc_intel->bits) % 16, "microcode data incorrectly aligned")) diff --git a/arch/x86/kernel/cpu/microcode/intel_early.c b/arch/x86/kernel/cpu/microcode/intel_early.c index 994c59b..095db11 100644 --- a/arch/x86/kernel/cpu/microcode/intel_early.c +++ b/arch/x86/kernel/cpu/microcode/intel_early.c @@ -671,6 +671,8 @@ static int apply_microcode_early(struct mc_saved_data *mc_saved_data, if (mc_intel == NULL) return 0; + BUG_ON(mc_intel->hdr.hdrver != 1 || mc_intel->hdr.ldrver != 1); + mcu_data = mc_intel->bits; aligned_mcu_data = mc_intel->bits; -- 1.7.10.4