diff mbox series

[v3] vduse: Fix off by one in vduse_dev_mmap()

Message ID 98298b2f-7288-4b0b-8974-3d5111b589cb@moroto.mountain
State New
Headers
Series [v3] vduse: Fix off by one in vduse_dev_mmap() |

Commit Message

Dan Carpenter Feb. 28, 2024, 6:24 p.m. UTC 
  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.

 drivers/vdpa/vdpa_user/vduse_dev.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Stefan Hajnoczi Feb. 28, 2024, 7:19 p.m. UTC | #1 
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.
>
>  drivers/vdpa/vdpa_user/vduse_dev.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

Reviewed-by: Stefan Hajnoczi <stefanha@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
>
>
Cindy Lu Feb. 29, 2024, 7:21 a.m. UTC | #2 
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
> >
> >
>
diff mbox series

Patch

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)