mtd: nand: atmel: fix buffer overflow in atmel_pmecc_user

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Gitweb:     http://git.infradead.org/?p=mtd-2.6.git;a=commit;h=36de80740008e6a4a55115b4a92e2059e47c1cba
Commit:     36de80740008e6a4a55115b4a92e2059e47c1cba
Parent:     7e439681af82984045efc215437ebb2ca8d33a4c
Author:     Richard Genoud <richard.genoud at gmail.com>
AuthorDate: Wed Sep 27 14:49:17 2017 +0200
Committer:  Boris Brezillon <boris.brezillon at free-electrons.com>
CommitDate: Wed Sep 27 17:33:28 2017 +0200

    mtd: nand: atmel: fix buffer overflow in atmel_pmecc_user
    
    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@gmail.com
    Fixes: f88fc122cc34 ("mtd: nand: Cleanup/rework the atmel_nand driver")
    Cc: stable at vger.kernel.org
    Reported-by: Richard Genoud <richard.genoud at gmail.com>
    Pointed-at-by: Boris Brezillon <boris.brezillon at free-electrons.com>
    Signed-off-by: Richard Genoud <richard.genoud at gmail.com>
    Reviewed-by: Nicolas Ferre <nicolas.ferre at microchip.com>
    Signed-off-by: Boris Brezillon <boris.brezillon at free-electrons.com>
---
 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 146af821..8268636 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)