EDAC, sb_edac: Fix out of bound writes during DIMM configuration on KNL
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 <[email protected]>
Signed-off-by: Anna Karbownik <[email protected]>
Cc: Mauro Carvalho Chehab <[email protected]>
Cc: Tony Luck <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: linux-edac <[email protected]>
Cc: <[email protected]>
Fixes: 3286d3eb906c ("EDAC, sb_edac: Drop NUM_CHANNELS from 8 back to 4")
Link: http://lkml.kernel.org/r/[email protected]
[ Massage commit message. ]
Signed-off-by: Borislav Petkov <[email protected]>
diff --git a/drivers/edac/sb_edac.c b/drivers/edac/sb_edac.c
index f34430f..8721002 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 */
