[PATCH mtd-utils] misc-utils: flash_erase: FIX integer overflow in flash_erase.c

[Zhihao Cheng]

在 2024/12/11 22:04, Anton Moryakov 写道:
> Report of the static analyzer:
> The value of an arithmetic expression 'eb_cnt * mtd.eb_size' is a subject to overflow because its operands are not cast to a larger data type before performing arithmetic
> 
> Corrections explained:
> Added explicit casting of eb_cnt to long long in the condition
> if (eb_start == 0 && mtd.size == eb_cnt * mtd.eb_size)
> to ensure the multiplication is performed in a 64-bit context,
> preventing potential overflow for large values of eb_cnt and mtd.eb_size.
> This ensures correct handling of devices with large block counts or block sizes.
> 
> Triggers found by static analyzer Svace.
> 
> Signed-off-by: Anton Moryakov <ant.v.moryakov at gmail.com>
> 
> ---
>   misc-utils/flash_erase.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)

Reviewed-by: Zhihao Cheng <chengzhihao1 at huawei.com>
> 
> diff --git a/misc-utils/flash_erase.c b/misc-utils/flash_erase.c
> index c6f6f66..78a3bd1 100644
> --- a/misc-utils/flash_erase.c
> +++ b/misc-utils/flash_erase.c
> @@ -239,7 +239,7 @@ int main(int argc, char *argv[])
>   	if (eb_cnt == 0)
>   		eb_cnt = (mtd.size / mtd.eb_size) - eb_start;
>   
> -	if (eb_start == 0 && mtd.size == eb_cnt * mtd.eb_size)
> +	if (eb_start == 0 && mtd.size == (long long)eb_cnt * mtd.eb_size)
>   		erase_chip = true;
>   
>   	/* If MTD device may have bad eraseblocks,
>