Re: [PATCH] xfs: fix SIGFPE bug in align_ag_geometry

[Gao Xiang <hsiangkao@redhat.com>]

On Thu, Apr 01, 2021 at 09:58:53AM +0800, lixiaokeng wrote:
> In some case, the cfg->dsunit is 32, the cfg->dswidth is zero
> and cfg->agsize is 6400 in align_ag_geometry. So, the
> (cfg->agsize % cfg->dswidth) will lead to coredump.
> 
> Here add check cfg->dswidth. If it is zero, goto validate.
> 

May I ask what's the command line? and is it reproducable on
the latest upstream version?

Thanks,
Gao Xiang

> Signed-off-by: Lixiaokeng <lixiaokeng@huawei.com>
> ---
>  mkfs/xfs_mkfs.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/mkfs/xfs_mkfs.c b/mkfs/xfs_mkfs.c
> index a135e06..71d3f74 100644
> --- a/mkfs/xfs_mkfs.c
> +++ b/mkfs/xfs_mkfs.c
> @@ -2725,6 +2725,9 @@ _("agsize rounded to %lld, sunit = %d\n"),
>  				(long long)cfg->agsize, dsunit);
>  	}
> 
> +	if (!cfg->dswidth)
> +		goto validate;
> +
>  	if ((cfg->agsize % cfg->dswidth) == 0 &&
>  	    cfg->dswidth != cfg->dsunit &&
>  	    cfg->agcount > 1) {
> -- 
>