From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:42798 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964929AbeCGTnX (ORCPT ); Wed, 7 Mar 2018 14:43:23 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dan Carpenter , Anna Karbownik , Mauro Carvalho Chehab , Tony Luck , jim.m.snow@intel.com, krzysztof.paliswiat@intel.com, lukasz.odzioba@intel.com, qiuxu.zhuo@intel.com, linux-edac , Borislav Petkov Subject: [PATCH 4.15 100/122] EDAC, sb_edac: Fix out of bound writes during DIMM configuration on KNL Date: Wed, 7 Mar 2018 11:38:32 -0800 Message-Id: <20180307191743.848319164@linuxfoundation.org> In-Reply-To: <20180307191729.190879024@linuxfoundation.org> References: <20180307191729.190879024@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Anna Karbownik commit bf8486709ac7fad99e4040dea73fe466c57a4ae1 upstream. Commit 3286d3eb906c ("EDAC, sb_edac: Drop NUM_CHANNELS from 8 back to 4") decreased NUM_CHANNELS from 8 to 4, but this is not enough for Knights Landing which supports up to 6 channels. This caused out-of-bounds writes to pvt->mirror_mode and pvt->tolm variables which don't pay critical role on KNL code path, so the memory corruption wasn't causing any visible driver failures. The easiest way of fixing it is to change NUM_CHANNELS to 6. Do that. An alternative solution would be to restructure the KNL part of the driver to 2MC/3channel representation. Reported-by: Dan Carpenter Signed-off-by: Anna Karbownik Cc: Mauro Carvalho Chehab Cc: Tony Luck Cc: jim.m.snow@intel.com Cc: krzysztof.paliswiat@intel.com Cc: lukasz.odzioba@intel.com Cc: qiuxu.zhuo@intel.com Cc: linux-edac Cc: Fixes: 3286d3eb906c ("EDAC, sb_edac: Drop NUM_CHANNELS from 8 back to 4") Link: http://lkml.kernel.org/r/1519312693-4789-1-git-send-email-anna.karbownik@intel.com [ Massage commit message. ] Signed-off-by: Borislav Petkov Signed-off-by: Greg Kroah-Hartman --- drivers/edac/sb_edac.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/edac/sb_edac.c +++ b/drivers/edac/sb_edac.c @@ -279,7 +279,7 @@ static const u32 correrrthrsld[] = { * sbridge structs */ -#define NUM_CHANNELS 4 /* Max channels per MC */ +#define NUM_CHANNELS 6 /* Max channels per MC */ #define MAX_DIMMS 3 /* Max DIMMS per channel */ #define KNL_MAX_CHAS 38 /* KNL max num. of Cache Home Agents */ #define KNL_MAX_CHANNELS 6 /* KNL max num. of PCI channels */