From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933172AbcCGXXF (ORCPT ); Mon, 7 Mar 2016 18:23:05 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:39592 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754068AbcCGWzU (ORCPT ); Mon, 7 Mar 2016 17:55:20 -0500 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Colin Ian King , Borislav Petkov , "Kirill A . Shutemov" , Thomas Gleixner , Kamal Mostafa Subject: [PATCH 4.2.y-ckt 211/273] x86/mpx: Fix off-by-one comparison with nr_registers Date: Mon, 7 Mar 2016 14:50:02 -0800 Message-Id: <1457391064-6660-212-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1457391064-6660-1-git-send-email-kamal@canonical.com> References: <1457391064-6660-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 4.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.2.8-ckt5 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Colin Ian King commit 9bf148cb0812595bfdf5100bd2c07e9bec9c6ef5 upstream. In the unlikely event that regno == nr_registers then we get an array overrun on regoff because the invalid register check is currently off-by-one. Fix this with a check that regno is >= nr_registers instead. Detected with static analysis using CoverityScan. Fixes: fcc7ffd67991 "x86, mpx: Decode MPX instruction to get bound violation information" Signed-off-by: Colin Ian King Acked-by: Dave Hansen Cc: Borislav Petkov Cc: "Kirill A . Shutemov" Link: http://lkml.kernel.org/r/1456512931-3388-1-git-send-email-colin.king@canonical.com Signed-off-by: Thomas Gleixner Signed-off-by: Kamal Mostafa --- arch/x86/mm/mpx.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/mm/mpx.c b/arch/x86/mm/mpx.c index 27f8393..b77009c 100644 --- a/arch/x86/mm/mpx.c +++ b/arch/x86/mm/mpx.c @@ -160,7 +160,7 @@ static int get_reg_offset(struct insn *insn, struct pt_regs *regs, break; } - if (regno > nr_registers) { + if (regno >= nr_registers) { WARN_ONCE(1, "decoded an instruction with an invalid register"); return -EINVAL; } -- 2.7.0