4.15-stable review patch. If anyone has any objections, please let me know.
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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@int... [ 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 */