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SubjectRe: [PATCH v3] vduse: Fix off by one in vduse_dev_mmap()
On Thu, Feb 29, 2024 at 3:19 AM Stefan Hajnoczi <stefanha@gmail.com> wrote:
>
> On Wed, 28 Feb 2024 at 13:24, Dan Carpenter <dan.carpenter@linaro.org> wrote:
> >
> > The dev->vqs[] array has "dev->vq_num" elements. It's allocated in
> > vduse_dev_init_vqs(). Thus, this > comparison needs to be >= to avoid
> > reading one element beyond the end of the array.
> >
> > Add an array_index_nospec() as well to prevent speculation issues.
> >
> > Fixes: 316ecd1346b0 ("vduse: Add file operation for mmap")
> > Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
> > ---
> > v2: add array_index_nospec()
> > v3: I accidentally corrupted v2. Try again.
> >
Thanks for fix this
> > drivers/vdpa/vdpa_user/vduse_dev.c | 3 ++-
> > 1 file changed, 2 insertions(+), 1 deletion(-)
>
> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Cindy Lu <lulu@redhat.com>
> > diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
> > index b7a1fb88c506..eb914084c650 100644
> > --- a/drivers/vdpa/vdpa_user/vduse_dev.c
> > +++ b/drivers/vdpa/vdpa_user/vduse_dev.c
> > @@ -1532,9 +1532,10 @@ static int vduse_dev_mmap(struct file *file, struct vm_area_struct *vma)
> > if ((vma->vm_flags & VM_SHARED) == 0)
> > return -EINVAL;
> >
> > - if (index > dev->vq_num)
> > + if (index >= dev->vq_num)
> > return -EINVAL;
> >
> > + index = array_index_nospec(index, dev->vq_num);
> > vq = dev->vqs[index];
> > vaddr = vq->vdpa_reconnect_vaddr;
> > if (vaddr == 0)
> > --
> > 2.43.0
> >
> >
>


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