Skip to contentSkip to conversation

Patch "vfio: fix ioctl error handling" has been added to the 4.4-stable tree

PATCH [email protected] 1 participant 1 message Mar 4, 2016

Subsystems (3)
lore
Share & tools
lore

[email protected]

author maintainer Applied
#0 lore raw

This is a note to let you know that I've just added the patch titled

vfio: fix ioctl error handling

to the 4.4-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:
vfio-fix-ioctl-error-handling.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From 8160c4e455820d5008a1116d2dca35f0363bb062 Mon Sep 17 00:00:00 2001

From: "Michael S. Tsirkin" <[email protected]>
Date: Sun, 28 Feb 2016 16:31:39 +0200
Subject: vfio: fix ioctl error handling

From: Michael S. Tsirkin <[email protected]>

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.

---
 drivers/vfio/pci/vfio_pci.c                  |    9 ++++++---
 drivers/vfio/platform/vfio_platform_common.c |    9 ++++++---
 drivers/vfio/vfio_iommu_type1.c              |    6 ++++--
 3 files changed, 16 insertions(+), 8 deletions(-)
drivers/vfio/pci/vfio_pci.c +6 -3
@@ -446,7 +446,8 @@ static long vfio_pci_ioctl(void *device_
 		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;
@@ -520,7 +521,8 @@ static long vfio_pci_ioctl(void *device_
 			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;
@@ -555,7 +557,8 @@ static long vfio_pci_ioctl(void *device_
 		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;
drivers/vfio/platform/vfio_platform_common.c +6 -3
@@ -219,7 +219,8 @@ static long vfio_platform_ioctl(void *de
 		info.num_regions = vdev->num_regions;
 		info.num_irqs = vdev->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 vfio_region_info info;
@@ -240,7 +241,8 @@ static long vfio_platform_ioctl(void *de
 		info.size = vdev->regions[info.index].size;
 		info.flags = vdev->regions[info.index].flags;
 
-		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;
@@ -259,7 +261,8 @@ static long vfio_platform_ioctl(void *de
 		info.flags = vdev->irqs[info.index].flags;
 		info.count = vdev->irqs[info.index].count;
 
-		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;
drivers/vfio/vfio_iommu_type1.c +4 -2
@@ -999,7 +999,8 @@ static long vfio_iommu_type1_ioctl(void
 
 		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;
@@ -1032,7 +1033,8 @@ static long vfio_iommu_type1_ioctl(void
 		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;

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/vfio-fix-ioctl-error-handling.patch queue-4.4/arm-arm64-kvm-fix-ioctl-error-handling.patch queue-4.4/mips-kvm-fix-ioctl-error-handling.patch