[PATCH mtd-utils] nand-utils: Fix integer overflow in nandflipbits.c

[Zhihao Cheng]

在 2024/12/13 21:19, Anton Moryakov 写道:
> Report of the static analyzer:
> The value of an arithmetic expression 'bit_to_flip->block * mtd.eb_size + blkoffs' is a subject to overflow because its operands are not cast to a larger data type before performing arith$
> 
> Corrections explained:
> Prevent arithmetic overflow in OOB read operation
> Resolved an issue where the calculation of the offset in the OOB read operation could overflow due to operands not being cast to a larger data type. Specifically, the multiplication of bi$
> 
> Triggers found by static analyzer Svace.
> 
> Signed-off-by: Anton Moryakov <ant.v.moryakov at gmail.com>
> 
> ---
>   nand-utils/nandflipbits.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/nand-utils/nandflipbits.c b/nand-utils/nandflipbits.c
> index 7066408..ef663c6 100644
> --- a/nand-utils/nandflipbits.c
> +++ b/nand-utils/nandflipbits.c
> @@ -251,7 +251,7 @@ int main(int argc, char **argv)
>   			bufoffs += mtd.min_io_size;
>   
>   			ret = mtd_read_oob(mtd_desc, &mtd, fd,
> -					   bit_to_flip->block * mtd.eb_size +
> +					   (unsigned long long)bit_to_flip->block * (long long)mtd.eb_size +

Hi, Anton. Change it like:
(unsigned long long)bit_to_flip->block * mtd.eb_size + blkoffs
>   					   blkoffs,
>   					   mtd.oob_size, buffer + bufoffs);
>   			if (ret) {
>