[dm-devel] [PATCH 07/15] libmultipath: fix sgio_get_vpd looping

[Benjamin Marzinski]

On Fri, Jan 17, 2020 at 05:27:00PM +0100, Martin Wilck wrote:
> On Thu, 2020-01-16 at 20:18 -0600, Benjamin Marzinski wrote:
> 
> > diff --git a/tests/vpd.c b/tests/vpd.c
> > index d9f80eaa..4dbce010 100644
> > --- a/tests/vpd.c
> > +++ b/tests/vpd.c
> > @@ -306,7 +306,7 @@ static int create_vpd83(unsigned char *buf,
> > size_t bufsiz, const char *id,
> >  	default:
> >  		break;
> >  	}
> > -	put_unaligned_be16(n, buf + 2);
> > +	put_unaligned_be16(bufsiz, buf + 2);
> >  	return n + 4;
> >  }
> 
> I can see that you are trying to create a VPD with a certain given
> length. But this way you intentionally create a VPD that doesn't
> conform to the spec (offset 2 should contain the real length of the
> designator list, not some arbitrary value). This is dangerous, in the
> future someone may copy this code thinking that it creates a valid
> VPD. At least you should add a big fat comment. Better even, you
> should leave out this hunk and override the length value in the
> actual test (make_test_vpd_eui) if (sml == 1) (and also add a comment).

Sure.

-Ben

> 
> Regards
> Martin
>