Re: [PATCH] xfs_spaceman: fix potential overflowing expression in trim_f()

["Darrick J. Wong" <darrick.wong@oracle.com>]

On Thu, Jun 29, 2017 at 12:10:05PM -0500, Bill O'Donnell wrote:
> Prevent the potential overflow in expression calculating offset
> in trim_f(() by casting the first variable to off64_t (64bit signed).
> 
> Detected by CoverityScan, CID#1413771 Integer handling issues (OVERFLOW_BEFORE_WIDEN)
> 
> Signed-off-by: Bill O'Donnell <billodo@redhat.com>

Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>

--D

> ---
>  spaceman/trim.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/spaceman/trim.c b/spaceman/trim.c
> index 872f68d3..6df9e6a9 100644
> --- a/spaceman/trim.c
> +++ b/spaceman/trim.c
> @@ -77,7 +77,7 @@ trim_f(
>  		length = cvtnum(file->geom.blocksize, file->geom.sectsize,
>  				argv[optind + 1]);
>  	} else if (agno) {
> -		offset = agno * file->geom.agblocks * file->geom.blocksize;
> +		offset = (off64_t)agno * file->geom.agblocks * file->geom.blocksize;
>  		length = file->geom.agblocks * file->geom.blocksize;
>  	} else {
>  		offset = 0;
> -- 
> 2.13.0
> 
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