From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1423106AbcBZSzj (ORCPT ); Fri, 26 Feb 2016 13:55:39 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:50972 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754531AbcBZSzh (ORCPT ); Fri, 26 Feb 2016 13:55:37 -0500 From: Colin King To: Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" , x86@kernel.org, Dave Hansen , Borislav Petkov , "Kirill A . Shutemov" Cc: linux-kernel@vger.kernel.org Subject: [PATCH] x86/mpx: Fix off-by-one comparison with nr_registers Date: Fri, 26 Feb 2016 18:55:31 +0000 Message-Id: <1456512931-3388-1-git-send-email-colin.king@canonical.com> X-Mailer: git-send-email 2.7.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Colin Ian King 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. Signed-off-by: Colin Ian King --- 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 5584397..8047687 100644 --- a/arch/x86/mm/mpx.c +++ b/arch/x86/mm/mpx.c @@ -123,7 +123,7 @@ 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