[PATCH] mtd: nand: atmel: fix buffer overflow in atmel_pmecc_user

From: Richard Genoud
Date: Wed Sep 27 2017 - 08:49:28 EST


When calculating the size needed by struct atmel_pmecc_user *user,
the dmu and delta buffer sizes were forgotten.
This lead to a memory corruption (especially with a large ecc_strength).

Link: http://lkml.kernel.org/r/1506503157.3016.5.camel@xxxxxxxxx
Fixes: f88fc122cc34 ("mtd: nand: Cleanup/rework the atmel_nand driver")
Cc: Nicolas Ferre <nicolas.ferre@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Reported-by: Richard Genoud <richard.genoud@xxxxxxxxx>
Pointed-at-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Richard Genoud <richard.genoud@xxxxxxxxx>
---
drivers/mtd/nand/atmel/pmecc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mtd/nand/atmel/pmecc.c b/drivers/mtd/nand/atmel/pmecc.c
index 146af8218314..8268636675ef 100644
--- a/drivers/mtd/nand/atmel/pmecc.c
+++ b/drivers/mtd/nand/atmel/pmecc.c
@@ -363,7 +363,7 @@ atmel_pmecc_create_user(struct atmel_pmecc *pmecc,
size += (req->ecc.strength + 1) * sizeof(u16);
/* Reserve space for mu, dmu and delta. */
size = ALIGN(size, sizeof(s32));
- size += (req->ecc.strength + 1) * sizeof(s32);
+ size += (req->ecc.strength + 1) * sizeof(s32) * 3;

user = kzalloc(size, GFP_KERNEL);
if (!user)