Patch "EDAC, sb_edac: Fix out of bound writes during DIMM configuration on KNL" has been added to the 4.14-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    EDAC, sb_edac: Fix out of bound writes during DIMM configuration on KNL

to the 4.14-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     edac-sb_edac-fix-out-of-bound-writes-during-dimm-configuration-on-knl.patch
and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From bf8486709ac7fad99e4040dea73fe466c57a4ae1 Mon Sep 17 00:00:00 2001
From: Anna Karbownik <anna.karbownik@intel.com>
Date: Thu, 22 Feb 2018 16:18:13 +0100
Subject: EDAC, sb_edac: Fix out of bound writes during DIMM configuration on KNL

From: Anna Karbownik <anna.karbownik@intel.com>

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 <dan.carpenter@oracle.com>
Signed-off-by: Anna Karbownik <anna.karbownik@intel.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: jim.m.snow@intel.com
Cc: krzysztof.paliswiat@intel.com
Cc: lukasz.odzioba@intel.com
Cc: qiuxu.zhuo@intel.com
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: <stable@vger.kernel.org>
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 <bp@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 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 */


Patches currently in stable-queue which might be from anna.karbownik@intel.com are

queue-4.14/edac-sb_edac-fix-out-of-bound-writes-during-dimm-configuration-on-knl.patch