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* [PATCH] vfio, iommu: Fixed interaction of VFIO_IOMMU_MAP_DMA with IOMMU address limits
@ 2013-08-27  9:57 Julian Stecklina
  2013-08-28 15:44   ` Alex Williamson
  0 siblings, 1 reply; 7+ messages in thread
From: Julian Stecklina @ 2013-08-27  9:57 UTC (permalink / raw)
  To: David.Woodhouse, alex.williamson; +Cc: Julian Stecklina, linux-kernel, iommu

The BUG_ON in drivers/iommu/intel-iommu.c:785 can be triggered from userspace via
VFIO by calling the VFIO_IOMMU_MAP_DMA ioctl on a vfio device with any address
beyond the addressing capabilities of the IOMMU. The problem is that the ioctl code
calls iommu_iova_to_phys before it calls iommu_map. iommu_map handles the case that
it gets addresses beyond the addressing capabilities of its IOMMU.
intel_iommu_iova_to_phys does not.

This patch fixes iommu_iova_to_phys to return NULL for addresses beyond what the
IOMMU can handle. This in turn causes the ioctl call to fail in iommu_map and
(correctly) return EFAULT to the user with a helpful warning message in the kernel
log.

Signed-off-by: Julian Stecklina <jsteckli@os.inf.tu-dresden.de>
---
 drivers/iommu/intel-iommu.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index eec0d3e..61303db 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -782,7 +782,11 @@ static struct dma_pte *pfn_to_dma_pte(struct dmar_domain *domain,
 	int offset;
 
 	BUG_ON(!domain->pgd);
-	BUG_ON(addr_width < BITS_PER_LONG && pfn >> addr_width);
+
+	if (addr_width < BITS_PER_LONG && pfn >> addr_width)
+		/* Address beyond IOMMU's addressing capabilities. */
+		return NULL;
+
 	parent = domain->pgd;
 
 	while (level > 0) {
-- 
1.8.3.1


^ permalink raw reply related	[flat|nested] 7+ messages in thread

* Re: [PATCH] vfio, iommu: Fixed interaction of VFIO_IOMMU_MAP_DMA with IOMMU address limits
@ 2013-08-28 15:44   ` Alex Williamson
  0 siblings, 0 replies; 7+ messages in thread
From: Alex Williamson @ 2013-08-28 15:44 UTC (permalink / raw)
  To: Julian Stecklina; +Cc: David.Woodhouse, linux-kernel, iommu

On Tue, 2013-08-27 at 11:57 +0200, Julian Stecklina wrote:
> The BUG_ON in drivers/iommu/intel-iommu.c:785 can be triggered from userspace via
> VFIO by calling the VFIO_IOMMU_MAP_DMA ioctl on a vfio device with any address
> beyond the addressing capabilities of the IOMMU. The problem is that the ioctl code
> calls iommu_iova_to_phys before it calls iommu_map. iommu_map handles the case that
> it gets addresses beyond the addressing capabilities of its IOMMU.
> intel_iommu_iova_to_phys does not.
> 
> This patch fixes iommu_iova_to_phys to return NULL for addresses beyond what the
> IOMMU can handle. This in turn causes the ioctl call to fail in iommu_map and
> (correctly) return EFAULT to the user with a helpful warning message in the kernel
> log.
> 
> Signed-off-by: Julian Stecklina <jsteckli@os.inf.tu-dresden.de>

Acked-by: Alex Williamson <alex.williamson@redhat.com>

> ---
>  drivers/iommu/intel-iommu.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
> index eec0d3e..61303db 100644
> --- a/drivers/iommu/intel-iommu.c
> +++ b/drivers/iommu/intel-iommu.c
> @@ -782,7 +782,11 @@ static struct dma_pte *pfn_to_dma_pte(struct dmar_domain *domain,
>  	int offset;
>  
>  	BUG_ON(!domain->pgd);
> -	BUG_ON(addr_width < BITS_PER_LONG && pfn >> addr_width);
> +
> +	if (addr_width < BITS_PER_LONG && pfn >> addr_width)
> +		/* Address beyond IOMMU's addressing capabilities. */
> +		return NULL;
> +
>  	parent = domain->pgd;
>  
>  	while (level > 0) {




^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH] vfio, iommu: Fixed interaction of VFIO_IOMMU_MAP_DMA with IOMMU address limits
@ 2013-08-28 15:44   ` Alex Williamson
  0 siblings, 0 replies; 7+ messages in thread
From: Alex Williamson @ 2013-08-28 15:44 UTC (permalink / raw)
  To: Julian Stecklina
  Cc: iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA,
	David.Woodhouse-ral2JQCrhuEAvxtiuMwx3w,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA

On Tue, 2013-08-27 at 11:57 +0200, Julian Stecklina wrote:
> The BUG_ON in drivers/iommu/intel-iommu.c:785 can be triggered from userspace via
> VFIO by calling the VFIO_IOMMU_MAP_DMA ioctl on a vfio device with any address
> beyond the addressing capabilities of the IOMMU. The problem is that the ioctl code
> calls iommu_iova_to_phys before it calls iommu_map. iommu_map handles the case that
> it gets addresses beyond the addressing capabilities of its IOMMU.
> intel_iommu_iova_to_phys does not.
> 
> This patch fixes iommu_iova_to_phys to return NULL for addresses beyond what the
> IOMMU can handle. This in turn causes the ioctl call to fail in iommu_map and
> (correctly) return EFAULT to the user with a helpful warning message in the kernel
> log.
> 
> Signed-off-by: Julian Stecklina <jsteckli-IG//nw+yl+iQIjdd1DhZXWfrygkm6VTR@public.gmane.org>

Acked-by: Alex Williamson <alex.williamson-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>

> ---
>  drivers/iommu/intel-iommu.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
> index eec0d3e..61303db 100644
> --- a/drivers/iommu/intel-iommu.c
> +++ b/drivers/iommu/intel-iommu.c
> @@ -782,7 +782,11 @@ static struct dma_pte *pfn_to_dma_pte(struct dmar_domain *domain,
>  	int offset;
>  
>  	BUG_ON(!domain->pgd);
> -	BUG_ON(addr_width < BITS_PER_LONG && pfn >> addr_width);
> +
> +	if (addr_width < BITS_PER_LONG && pfn >> addr_width)
> +		/* Address beyond IOMMU's addressing capabilities. */
> +		return NULL;
> +
>  	parent = domain->pgd;
>  
>  	while (level > 0) {

^ permalink raw reply	[flat|nested] 7+ messages in thread

* [PATCH] vfio, iommu: Fixed interaction of VFIO_IOMMU_MAP_DMA with IOMMU address limits
@ 2013-10-09  8:03     ` Julian Stecklina
  0 siblings, 0 replies; 7+ messages in thread
From: Julian Stecklina @ 2013-10-09  8:03 UTC (permalink / raw)
  To: Joerg Roedel, David Woodhouse
  Cc: Julian Stecklina, Alex Williamson, linux-kernel, iommu

The BUG_ON in drivers/iommu/intel-iommu.c:785 can be triggered from userspace via
VFIO by calling the VFIO_IOMMU_MAP_DMA ioctl on a vfio device with any address
beyond the addressing capabilities of the IOMMU. The problem is that the ioctl code
calls iommu_iova_to_phys before it calls iommu_map. iommu_map handles the case that
it gets addresses beyond the addressing capabilities of its IOMMU.
intel_iommu_iova_to_phys does not.

This patch fixes iommu_iova_to_phys to return NULL for addresses beyond what the
IOMMU can handle. This in turn causes the ioctl call to fail in iommu_map and
(correctly) return EFAULT to the user with a helpful warning message in the kernel
log.

Signed-off-by: Julian Stecklina <jsteckli@os.inf.tu-dresden.de>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
---
 drivers/iommu/intel-iommu.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 15e9b57..40203ad 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -782,7 +782,11 @@ static struct dma_pte *pfn_to_dma_pte(struct dmar_domain *domain,
 	int offset;
 
 	BUG_ON(!domain->pgd);
-	BUG_ON(addr_width < BITS_PER_LONG && pfn >> addr_width);
+
+	if (addr_width < BITS_PER_LONG && pfn >> addr_width)
+		/* Address beyond IOMMU's addressing capabilities. */
+		return NULL;
+
 	parent = domain->pgd;
 
 	while (level > 0) {
-- 
1.8.3.1


^ permalink raw reply related	[flat|nested] 7+ messages in thread

* [PATCH] vfio, iommu: Fixed interaction of VFIO_IOMMU_MAP_DMA with IOMMU address limits
@ 2013-10-09  8:03     ` Julian Stecklina
  0 siblings, 0 replies; 7+ messages in thread
From: Julian Stecklina @ 2013-10-09  8:03 UTC (permalink / raw)
  To: Joerg Roedel, David Woodhouse
  Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA,
	iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA,
	Julian Stecklina

The BUG_ON in drivers/iommu/intel-iommu.c:785 can be triggered from userspace via
VFIO by calling the VFIO_IOMMU_MAP_DMA ioctl on a vfio device with any address
beyond the addressing capabilities of the IOMMU. The problem is that the ioctl code
calls iommu_iova_to_phys before it calls iommu_map. iommu_map handles the case that
it gets addresses beyond the addressing capabilities of its IOMMU.
intel_iommu_iova_to_phys does not.

This patch fixes iommu_iova_to_phys to return NULL for addresses beyond what the
IOMMU can handle. This in turn causes the ioctl call to fail in iommu_map and
(correctly) return EFAULT to the user with a helpful warning message in the kernel
log.

Signed-off-by: Julian Stecklina <jsteckli-IG//nw+yl+iQIjdd1DhZXWfrygkm6VTR@public.gmane.org>
Acked-by: Alex Williamson <alex.williamson-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
---
 drivers/iommu/intel-iommu.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 15e9b57..40203ad 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -782,7 +782,11 @@ static struct dma_pte *pfn_to_dma_pte(struct dmar_domain *domain,
 	int offset;
 
 	BUG_ON(!domain->pgd);
-	BUG_ON(addr_width < BITS_PER_LONG && pfn >> addr_width);
+
+	if (addr_width < BITS_PER_LONG && pfn >> addr_width)
+		/* Address beyond IOMMU's addressing capabilities. */
+		return NULL;
+
 	parent = domain->pgd;
 
 	while (level > 0) {
-- 
1.8.3.1

^ permalink raw reply related	[flat|nested] 7+ messages in thread

* Re: [PATCH] vfio, iommu: Fixed interaction of VFIO_IOMMU_MAP_DMA with IOMMU address limits
@ 2013-11-01 11:53       ` Joerg Roedel
  0 siblings, 0 replies; 7+ messages in thread
From: Joerg Roedel @ 2013-11-01 11:53 UTC (permalink / raw)
  To: Julian Stecklina; +Cc: David Woodhouse, Alex Williamson, linux-kernel, iommu

On Wed, Oct 09, 2013 at 10:03:52AM +0200, Julian Stecklina wrote:
> The BUG_ON in drivers/iommu/intel-iommu.c:785 can be triggered from userspace via
> VFIO by calling the VFIO_IOMMU_MAP_DMA ioctl on a vfio device with any address
> beyond the addressing capabilities of the IOMMU. The problem is that the ioctl code
> calls iommu_iova_to_phys before it calls iommu_map. iommu_map handles the case that
> it gets addresses beyond the addressing capabilities of its IOMMU.
> intel_iommu_iova_to_phys does not.
> 
> This patch fixes iommu_iova_to_phys to return NULL for addresses beyond what the
> IOMMU can handle. This in turn causes the ioctl call to fail in iommu_map and
> (correctly) return EFAULT to the user with a helpful warning message in the kernel
> log.
> 
> Signed-off-by: Julian Stecklina <jsteckli@os.inf.tu-dresden.de>
> Acked-by: Alex Williamson <alex.williamson@redhat.com>

Applied, thanks.


^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH] vfio, iommu: Fixed interaction of VFIO_IOMMU_MAP_DMA with IOMMU address limits
@ 2013-11-01 11:53       ` Joerg Roedel
  0 siblings, 0 replies; 7+ messages in thread
From: Joerg Roedel @ 2013-11-01 11:53 UTC (permalink / raw)
  To: Julian Stecklina
  Cc: David Woodhouse,
	iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA

On Wed, Oct 09, 2013 at 10:03:52AM +0200, Julian Stecklina wrote:
> The BUG_ON in drivers/iommu/intel-iommu.c:785 can be triggered from userspace via
> VFIO by calling the VFIO_IOMMU_MAP_DMA ioctl on a vfio device with any address
> beyond the addressing capabilities of the IOMMU. The problem is that the ioctl code
> calls iommu_iova_to_phys before it calls iommu_map. iommu_map handles the case that
> it gets addresses beyond the addressing capabilities of its IOMMU.
> intel_iommu_iova_to_phys does not.
> 
> This patch fixes iommu_iova_to_phys to return NULL for addresses beyond what the
> IOMMU can handle. This in turn causes the ioctl call to fail in iommu_map and
> (correctly) return EFAULT to the user with a helpful warning message in the kernel
> log.
> 
> Signed-off-by: Julian Stecklina <jsteckli-IG//nw+yl+iQIjdd1DhZXWfrygkm6VTR@public.gmane.org>
> Acked-by: Alex Williamson <alex.williamson-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>

Applied, thanks.

^ permalink raw reply	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2013-11-01 11:53 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2013-08-27  9:57 [PATCH] vfio, iommu: Fixed interaction of VFIO_IOMMU_MAP_DMA with IOMMU address limits Julian Stecklina
2013-08-28 15:44 ` Alex Williamson
2013-08-28 15:44   ` Alex Williamson
2013-10-09  8:03   ` Julian Stecklina
2013-10-09  8:03     ` Julian Stecklina
2013-11-01 11:53     ` Joerg Roedel
2013-11-01 11:53       ` Joerg Roedel

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