Re: [PATCH] vhost: vringh: Modify the return value check

["Michael S. Tsirkin" <mst@redhat.com>]

On Sun, Sep 21, 2025 at 04:59:36PM -0400, Michael S. Tsirkin wrote:
> On Wed, Sep 10, 2025 at 05:17:38PM +0800, zhangjiao2 wrote:
> > From: zhang jiao <zhangjiao2@cmss.chinamobile.com>
> > 
> > The return value of copy_from_iter and copy_to_iter can't be negative,
> > check whether the copied lengths are equal.
> > 
> > Signed-off-by: zhang jiao <zhangjiao2@cmss.chinamobile.com>
> 
> Well I don't see a fix for copy_to_iter here.
> 
> 
>                 ret = copy_to_iter(src, translated, &iter);
>                 if (ret < 0)
>                         return ret;
> 

to clarify, pls send an additional patch to copy that one.

> 
> 
> 
> > ---
> >  drivers/vhost/vringh.c | 7 ++++---
> >  1 file changed, 4 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c
> > index 9f27c3f6091b..0c8a17cbb22e 100644
> > --- a/drivers/vhost/vringh.c
> > +++ b/drivers/vhost/vringh.c
> > @@ -1115,6 +1115,7 @@ static inline int copy_from_iotlb(const struct vringh *vrh, void *dst,
> >  		struct iov_iter iter;
> >  		u64 translated;
> >  		int ret;
> > +		size_t size;
> >  
> >  		ret = iotlb_translate(vrh, (u64)(uintptr_t)src,
> >  				      len - total_translated, &translated,
> > @@ -1132,9 +1133,9 @@ static inline int copy_from_iotlb(const struct vringh *vrh, void *dst,
> >  				      translated);
> >  		}
> >  
> > -		ret = copy_from_iter(dst, translated, &iter);
> > -		if (ret < 0)
> > -			return ret;
> > +		size = copy_from_iter(dst, translated, &iter);
> > +		if (size != translated)
> > +			return -EFAULT;
> >  
> >  		src += translated;
> >  		dst += translated;
> > -- 
> > 2.33.0
> > 
> >