2021-04-13 07:18:30

by Christian A. Ehrhardt

[permalink] [raw]

Subject: [PATCH] vfio/pci: Add missing range check in vfio_pci_mmap

---

When mmaping an extra device region verify that the region index
derived from the mmap offset is valid.

Fixes: a15b1883fee1 ("vfio_pci: Allow mapping extra regions")
Cc: [email protected]
Signed-off-by: Christian A. Ehrhardt <[email protected]>
---
drivers/vfio/pci/vfio_pci.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index 65e7e6b44578..5023e23db3bc 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -1656,6 +1656,8 @@ static int vfio_pci_mmap(void *device_data, struct vm_area_struct *vma)

index = vma->vm_pgoff >> (VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT);

+ if (index >= VFIO_PCI_NUM_REGIONS + vdev->num_regions)
+ return -EINVAL;
if (vma->vm_end < vma->vm_start)
return -EINVAL;
if ((vma->vm_flags & VM_SHARED) == 0)
@@ -1664,7 +1666,7 @@ static int vfio_pci_mmap(void *device_data, struct vm_area_struct *vma)
int regnum = index - VFIO_PCI_NUM_REGIONS;
struct vfio_pci_region *region = vdev->region + regnum;

- if (region && region->ops && region->ops->mmap &&
+ if (region->ops && region->ops->mmap &&
(region->flags & VFIO_REGION_INFO_FLAG_MMAP))
return region->ops->mmap(vdev, region, vma);
return -EINVAL;
--
2.25.1

2021-04-13 07:40:05

by David Gibson

[permalink] [raw]

Subject: Re: [PATCH] vfio/pci: Add missing range check in vfio_pci_mmap

---

On Mon, Apr 12, 2021 at 11:41:24PM +0200, Christian A. Ehrhardt wrote:
>
> When mmaping an extra device region verify that the region index
> derived from the mmap offset is valid.
>
> Fixes: a15b1883fee1 ("vfio_pci: Allow mapping extra regions")
> Cc: [email protected]
> Signed-off-by: Christian A. Ehrhardt <[email protected]>

Reviewed-by: David Gibson <[email protected]>

> ---
> drivers/vfio/pci/vfio_pci.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
> index 65e7e6b44578..5023e23db3bc 100644
> --- a/drivers/vfio/pci/vfio_pci.c
> +++ b/drivers/vfio/pci/vfio_pci.c
> @@ -1656,6 +1656,8 @@ static int vfio_pci_mmap(void *device_data, struct vm_area_struct *vma)
>
> index = vma->vm_pgoff >> (VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT);
>
> + if (index >= VFIO_PCI_NUM_REGIONS + vdev->num_regions)
> + return -EINVAL;
> if (vma->vm_end < vma->vm_start)
> return -EINVAL;
> if ((vma->vm_flags & VM_SHARED) == 0)
> @@ -1664,7 +1666,7 @@ static int vfio_pci_mmap(void *device_data, struct vm_area_struct *vma)
> int regnum = index - VFIO_PCI_NUM_REGIONS;
> struct vfio_pci_region *region = vdev->region + regnum;
>
> - if (region && region->ops && region->ops->mmap &&
> + if (region->ops && region->ops->mmap &&
> (region->flags & VFIO_REGION_INFO_FLAG_MMAP))
> return region->ops->mmap(vdev, region, vma);
> return -EINVAL;

--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson

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2021-04-13 12:45:33

by Cornelia Huck

[permalink] [raw]

Subject: Re: [PATCH] vfio/pci: Add missing range check in vfio_pci_mmap

---

On Mon, 12 Apr 2021 23:41:24 +0200
"Christian A. Ehrhardt" <[email protected]> wrote:

> When mmaping an extra device region verify that the region index
> derived from the mmap offset is valid.
>
> Fixes: a15b1883fee1 ("vfio_pci: Allow mapping extra regions")
> Cc: [email protected]
> Signed-off-by: Christian A. Ehrhardt <[email protected]>
> ---
> drivers/vfio/pci/vfio_pci.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)

Reviewed-by: Cornelia Huck <[email protected]>