[PATCH v2] mtd: diskonchip: Cast an operand to uint64_t to prevent potential uint32_t overflow in inftl_partscan()

[Gax-c]

From: Zichen Xie <zichenxie0106 at gmail.com>

This was found by a static analyzer.
There may be a potential integer overflow issue in
inftl_partscan(). parts[0].size is defined as "uint64_t"
while mtd->erasesize and ip->firstUnit are defined as 32-bit
unsigned integer. The result of the calculation will be limited
to 32 bits without correct casting.
So, we recommend adding an extra cast to prevent potential
integer overflow.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Zichen Xie <zichenxie0106 at gmail.com>
---
v2: correct "Fixes" tag.
---
 drivers/mtd/nand/raw/diskonchip.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mtd/nand/raw/diskonchip.c b/drivers/mtd/nand/raw/diskonchip.c
index 8db7fc424571..70d6c2250f32 100644
--- a/drivers/mtd/nand/raw/diskonchip.c
+++ b/drivers/mtd/nand/raw/diskonchip.c
@@ -1098,7 +1098,7 @@ static inline int __init inftl_partscan(struct mtd_info *mtd, struct mtd_partiti
 		    (i == 0) && (ip->firstUnit > 0)) {
 			parts[0].name = " DiskOnChip IPL / Media Header partition";
 			parts[0].offset = 0;
-			parts[0].size = mtd->erasesize * ip->firstUnit;
+			parts[0].size = (uint64_t)mtd->erasesize * ip->firstUnit;
 			numparts = 1;
 		}
 
-- 
2.34.1