From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934285AbcIPLYZ (ORCPT ); Fri, 16 Sep 2016 07:24:25 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:58122 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934367AbcIPLYF (ORCPT ); Fri, 16 Sep 2016 07:24:05 -0400 From: Colin King To: Borislav Petkov , Aravind Gopalakrishnan , Yazen Ghannam , Peter Zijlstra Cc: linux-kernel@vger.kernel.org Subject: [PATCH][V2][Fix commit message] x86/RAS/mce_amd_inj: fix signed wrap around when decrementing index i Date: Fri, 16 Sep 2016 12:22:23 +0100 Message-Id: <20160916112223.32398-1-colin.king@canonical.com> X-Mailer: git-send-email 2.9.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Colin Ian King Integer index i needs to be a signed int rather than unsigned to avoid a wrap-around when decrementing in the while loop. For example, if the debugfs_create_file fails when i is zero, the current situation will predecrement i in the while loop, wrapping i to the maximum signed integer and cause multiple out of bounds reads on dfs_fls[i].d as the loop interates to zero. Also add (int) cast to fix warning that the original fix attempted to fix. Fixes: 7cc4ef8ed132 ("x86/RAS/mce_amd_inj: Fix some W= warnings") Signed-off-by: Colin Ian King --- arch/x86/ras/mce_amd_inj.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/ras/mce_amd_inj.c b/arch/x86/ras/mce_amd_inj.c index cd318d9..cb9779a 100644 --- a/arch/x86/ras/mce_amd_inj.c +++ b/arch/x86/ras/mce_amd_inj.c @@ -440,7 +440,7 @@ static struct dfs_node { static int __init init_mce_inject(void) { - unsigned int i; + int i; u64 cap; rdmsrl(MSR_IA32_MCG_CAP, cap); @@ -450,7 +450,7 @@ static int __init init_mce_inject(void) if (!dfs_inj) return -EINVAL; - for (i = 0; i < ARRAY_SIZE(dfs_fls); i++) { + for (i = 0; i < (int)ARRAY_SIZE(dfs_fls); i++) { dfs_fls[i].d = debugfs_create_file(dfs_fls[i].name, dfs_fls[i].perm, dfs_inj, -- 2.9.3