From 11b662c0c328e2f9d6d20e44036d7cd07adb22f8 Mon Sep 17 00:00:00 2001 From: Anna Karbownik Date: Thu, 22 Feb 2018 16:18:13 +0100 Subject: [PATCH] EDAC, sb_edac: Fix out of bound writes during DIMM configuration on KNL Commit 29def948abe6 ("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: 29def948abe6 ("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 --- drivers/edac/sb_edac.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/edac/sb_edac.c b/drivers/edac/sb_edac.c index f34430f99fd80..872100215ca00 100644 --- 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 */ -- 2.39.5