[PATCH v3] mtd: spi-nor: cast to u64 to avoid uint overflows

[Huijin Park]

From: "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 <***@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. */

[Geert Uytterhoeven]

Post by Huijin Park
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.

Reviewed-by: Geert Uytterhoeven <geert+***@glider.be>

Gr{oetje,eeting}s,

Geert

[Boris Brezillon]

Post by Huijin Park
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.

Applied to http://git.infradead.org/linux-mtd.git mtd/next, thanks.

Boris

[Boris Brezillon]

On Mon, 3 Dec 2018 08:51:54 +0100

Post by Boris Brezillon

Post by Huijin Park
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.

Applied to http://git.infradead.org/linux-mtd.git mtd/next, thanks.

Oops, should I been queued to spi-nor/next. I dropped the patch and
will soon push it to spi-nor/next.

[Rafał Miłecki]

Post by Huijin Park
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.

You may want to adjust your git's "user.name" config to avoid
"malforming" your name (From and Signed-off-by) in the further
contributions :)

Something like
git config --global user.name "John Foo"