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From:   Huijin Park <huijin.park@samsung.com>
To:     Boris Brezillon <boris.brezillon@bootlin.com>
Cc:     Marek Vasut <marek.vasut@gmail.com>, linux-mtd@lists.infradead.org,
        linux-kernel@vger.kernel.org,
        Huijin Park <huijin.park@samsung.com>, bbanghj.park@gmail.com,
        Geert Uytterhoeven <geert@linux-m68k.org>
Subject: [PATCH v3] mtd: spi-nor: cast to u64 to avoid uint overflows
Date:   Wed, 28 Nov 2018 03:02:14 -0500
Message-id: <1543392134-1443-1-git-send-email-huijin.park@samsung.com>
CMS-TYPE: 201P
References: <CGME20181128080244eucas1p15d9478c4fdbb0609005a12d24703d6d8@eucas1p1.samsung.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

From: "huijin.park" <huijin.park@samsung.com>

The "params->size" is defined as "u64".
And "info->sector_size" and "info->n_sectors" are defined as
unsigned int and u16.
Thus, u64 data might have strange data(loss data) if the result
overflows an unsigned int.
This patch casts "info->sector_size" to an u64.

Signed-off-by: huijin.park <huijin.park@samsung.com>
---

Changes since v1:
 * Made commit subject and message more clear.
Changes since v2:
 * Adding the cast to only the first operand.
---
 drivers/mtd/spi-nor/spi-nor.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index d9c368c..59a1075 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -2459,7 +2459,7 @@ static int spi_nor_init_params(struct spi_nor *nor,
 	memset(params, 0, sizeof(*params));
 
 	/* Set SPI NOR sizes. */
-	params->size = info->sector_size * info->n_sectors;
+	params->size = (u64)info->sector_size * info->n_sectors;
 	params->page_size = info->page_size;
 
 	/* (Fast) Read settings. */
-- 
1.7.9.5