[Ocfs2-tools-devel] [PATCH] tunefs.ocfs2: fix a potential overflowing problem in check_new_size

[Joseph Qi]

Hi Jun，
IMO，in this case, it will 100% overflow, not potential, am I right?

Thanks,
Joseph

On 2016/5/24 22:24, piaojun wrote:
> Potentially overflowing expression "0xffffffffU << b_to_c_bits" with
> type "unsigned int" (32 bits, unsigned) is evaluated using 32-bit
> arithmetic before being used in a context which expects an expression
> of type "uint64_t" (64 bits, unsigned). To avoid overflow, cast the left
> operand to "uint64_t" before performing the left shift.
> 
> Fixes: 15f01d8d8c1c ("tunefs.ocfs2: Warn if not using complete device")
> 
> Signed-off-by: Jun Piao <piaojun at huawei.com>
> ---
>  tunefs.ocfs2/op_resize_volume.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tunefs.ocfs2/op_resize_volume.c b/tunefs.ocfs2/op_resize_volume.c
> index 076bda0..84d8628 100644
> --- a/tunefs.ocfs2/op_resize_volume.c
> +++ b/tunefs.ocfs2/op_resize_volume.c
> @@ -543,7 +543,7 @@ static errcode_t check_new_size(ocfs2_filesys *fs, uint64_t new_size,
>  				 "Clusters (%"PRIu64" is greater than "
>  				 "maximum possible clusters %"PRIu32"\n",
>  				 device_clusters, UINT32_MAX);
> -			try_blocks = UINT32_MAX << b_to_c_bits;
> +			try_blocks = (uint64_t)UINT32_MAX << b_to_c_bits;
>  			errorf("Clusters %"PRIu64" is greater than max allowed"
>  			       " %"PRIu32".\nIf you want to resize to %"PRIu64
>  			       " blocks please specify %"PRIu64" as "
>