[PATCH v2 for-4.5] vfio: fix ioctl error handling
From: Michael S. Tsirkin
Date: Sun Feb 28 2016 - 08:52:08 EST
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
if (copy_to_user(...))
return -EFAULT;
return 0;
everywhere.
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
---
Changes from v1:
fix up good path logic to return 0.
Compiled only.
drivers/vfio/pci/vfio_pci.c | 12 +++++++++---
drivers/vfio/platform/vfio_platform_common.c | 12 +++++++++---
drivers/vfio/vfio_iommu_type1.c | 8 ++++++--
3 files changed, 24 insertions(+), 8 deletions(-)
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index 2760a7b..286b91f 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -446,7 +446,9 @@ 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);
+ if (copy_to_user((void __user *)arg, &info, minsz))
+ return -EFAULT;
+ return 0;
} else if (cmd == VFIO_DEVICE_GET_REGION_INFO) {
struct pci_dev *pdev = vdev->pdev;
@@ -520,7 +522,9 @@ static long vfio_pci_ioctl(void *device_data,
return -EINVAL;
}
- return copy_to_user((void __user *)arg, &info, minsz);
+ if (copy_to_user((void __user *)arg, &info, minsz))
+ return -EFAULT;
+ return 0;
} else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) {
struct vfio_irq_info info;
@@ -555,7 +559,9 @@ static long vfio_pci_ioctl(void *device_data,
else
info.flags |= VFIO_IRQ_INFO_NORESIZE;
- return copy_to_user((void __user *)arg, &info, minsz);
+ if (copy_to_user((void __user *)arg, &info, minsz))
+ return -EFAULT;
+ return 0;
} else if (cmd == VFIO_DEVICE_SET_IRQS) {
struct vfio_irq_set hdr;
diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
index 418cdd9..0fc6b75 100644
--- a/drivers/vfio/platform/vfio_platform_common.c
+++ b/drivers/vfio/platform/vfio_platform_common.c
@@ -219,7 +219,9 @@ static long vfio_platform_ioctl(void *device_data,
info.num_regions = vdev->num_regions;
info.num_irqs = vdev->num_irqs;
- return copy_to_user((void __user *)arg, &info, minsz);
+ if (copy_to_user((void __user *)arg, &info, minsz))
+ return -EFAULT;
+ return 0;
} else if (cmd == VFIO_DEVICE_GET_REGION_INFO) {
struct vfio_region_info info;
@@ -240,7 +242,9 @@ static long vfio_platform_ioctl(void *device_data,
info.size = vdev->regions[info.index].size;
info.flags = vdev->regions[info.index].flags;
- return copy_to_user((void __user *)arg, &info, minsz);
+ if (copy_to_user((void __user *)arg, &info, minsz))
+ return -EFAULT;
+ return 0;
} else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) {
struct vfio_irq_info info;
@@ -259,7 +263,9 @@ static long vfio_platform_ioctl(void *device_data,
info.flags = vdev->irqs[info.index].flags;
info.count = vdev->irqs[info.index].count;
- return copy_to_user((void __user *)arg, &info, minsz);
+ if (copy_to_user((void __user *)arg, &info, minsz))
+ return -EFAULT;
+ return 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 6f1ea3d..557dfc6 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -999,7 +999,9 @@ 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);
+ if (copy_to_user((void __user *)arg, &info, minsz))
+ return -EFAULT;
+ return 0;
} else if (cmd == VFIO_IOMMU_MAP_DMA) {
struct vfio_iommu_type1_dma_map map;
@@ -1032,7 +1034,9 @@ static long vfio_iommu_type1_ioctl(void *iommu_data,
if (ret)
return ret;
- return copy_to_user((void __user *)arg, &unmap, minsz);
+ if (copy_to_user((void __user *)arg, &unmap, minsz))
+ return -EFAULT;
+ return 0;
}
return -ENOTTY;
--
MST