From: "Michael S. Tsirkin" <mst@xxxxxxxxxx>
This patch has been added to the 3.18 stable tree. If you have any
objections, please let us know.
===============
[ Upstream commit 8160c4e455820d5008a1116d2dca35f0363bb062 ]
Calling return copy_to_user(...) in an ioctl will not
do the right thing if there's a pagefault:
copy_to_user returns the number of bytes not copied
in this case.
Fix up vfio to do
return copy_to_user(...)) ?
-EFAULT : 0;
everywhere.
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sasha.levin@xxxxxxxxxx>
---
drivers/vfio/pci/vfio_pci.c | 9 ++++++---
drivers/vfio/vfio_iommu_type1.c | 6 ++++--
2 files changed, 10 insertions(+), 5 deletions(-)
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index 2f8a055..bc7bc4e 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -375,7 +375,8 @@ static long vfio_pci_ioctl(void *device_data,
info.num_regions = VFIO_PCI_NUM_REGIONS;
info.num_irqs = VFIO_PCI_NUM_IRQS;
- return copy_to_user((void __user *)arg, &info, minsz);
+ return copy_to_user((void __user *)arg, &info, minsz) ?
+ -EFAULT : 0;
} else if (cmd == VFIO_DEVICE_GET_REGION_INFO) {
struct pci_dev *pdev = vdev->pdev;
@@ -448,7 +449,8 @@ static long vfio_pci_ioctl(void *device_data,
return -EINVAL;
}
- return copy_to_user((void __user *)arg, &info, minsz);
+ return copy_to_user((void __user *)arg, &info, minsz) ?
+ -EFAULT : 0;
} else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) {
struct vfio_irq_info info;
@@ -482,7 +484,8 @@ static long vfio_pci_ioctl(void *device_data,
else
info.flags |= VFIO_IRQ_INFO_NORESIZE;
- return copy_to_user((void __user *)arg, &info, minsz);
+ return copy_to_user((void __user *)arg, &info, minsz) ?
+ -EFAULT : 0;
} else if (cmd == VFIO_DEVICE_SET_IRQS) {
struct vfio_irq_set hdr;
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 4a9d666..3d1cbbd 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -928,7 +928,8 @@ static long vfio_iommu_type1_ioctl(void *iommu_data,
info.iova_pgsizes = vfio_pgsize_bitmap(iommu);
- return copy_to_user((void __user *)arg, &info, minsz);
+ return copy_to_user((void __user *)arg, &info, minsz) ?
+ -EFAULT : 0;
} else if (cmd == VFIO_IOMMU_MAP_DMA) {
struct vfio_iommu_type1_dma_map map;
@@ -961,7 +962,8 @@ static long vfio_iommu_type1_ioctl(void *iommu_data,
if (ret)
return ret;
- return copy_to_user((void __user *)arg, &unmap, minsz);
+ return copy_to_user((void __user *)arg, &unmap, minsz) ?
+ -EFAULT : 0;
}
return -ENOTTY;
--
2.5.0
--
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