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

[Gao Xiang <hsiangkao@redhat.com>]

On Thu, Apr 01, 2021 at 10:29:15AM +0800, Gao Xiang wrote:
> 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?

Btw, according to the line number of your patch format, it seems
your patch was based on "v4.17.0". May I ask which version you
were testing? If so, that is an outdated version, it'd be better
to try with latest version first.

Thanks,
Gao Xiang

> 
> 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) {
> > -- 
> >