@@ -346,7 +346,8 @@ 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;
@@ -419,7 +420,8 @@ 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;
@@ -453,7 +455,8 @@ 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;
@@ -908,7 +908,8 @@ 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;
@@ -941,7 +942,8 @@ 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;
This is a note to let you know that I have just added a patch titled vfio: fix ioctl error handling to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue This patch is scheduled to be released in version 3.16.7-ckt26. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.16.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ---8<------------------------------------------------------------ From ef90400029a857c6b45a6bbd9fd5e6f01bb4cfbb Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" <mst@redhat.com> Date: Sun, 28 Feb 2016 16:31:39 +0200 Subject: vfio: fix ioctl error handling commit 8160c4e455820d5008a1116d2dca35f0363bb062 upstream. 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. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> [ luis: backported to 3.16: - dropped changes to vfio_platform_common.c ] Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- drivers/vfio/pci/vfio_pci.c | 9 ++++++--- drivers/vfio/vfio_iommu_type1.c | 6 ++++-- 2 files changed, 10 insertions(+), 5 deletions(-)