This is a note to let you know that I've just added the patch titled
iommu/vt-d: Fixed interaction of VFIO_IOMMU_MAP_DMA with IOMMU address limits
to the 3.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
iommu-vt-d-fixed-interaction-of-vfio_iommu_map_dma-with-iommu-address-limits.patch
and it can be found in the queue-3.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From f9423606ade08653dd8a43334f0a7fb45504c5cc Mon Sep 17 00:00:00 2001
From: Julian Stecklina <jsteckli@xxxxxxxxxxxxxxxxxxxx>
Date: Wed, 9 Oct 2013 10:03:52 +0200
Subject: iommu/vt-d: Fixed interaction of VFIO_IOMMU_MAP_DMA with IOMMU address limits
From: Julian Stecklina <jsteckli@xxxxxxxxxxxxxxxxxxxx>
commit f9423606ade08653dd8a43334f0a7fb45504c5cc upstream.
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@xxxxxxxxxxxxxxxxxxxx>
Acked-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
Signed-off-by: Joerg Roedel <joro@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/iommu/intel-iommu.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -782,7 +782,11 @@ static struct dma_pte *pfn_to_dma_pte(st
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) {
Patches currently in stable-queue which might be from jsteckli@xxxxxxxxxxxxxxxxxxxx are
queue-3.10/iommu-vt-d-fixed-interaction-of-vfio_iommu_map_dma-with-iommu-address-limits.patch
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