vfio-pci: Fix possible integer overflow

BugLink: http://bugs.launchpad.net/bugs/1168506

commit 904c680c7b upstream.

The VFIO_DEVICE_SET_IRQS ioctl takes a start and count parameter, both
of which are unsigned.  We attempt to bounds check these, but fail to
account for the case where start is a very large number, allowing
start + count to wrap back into the valid range.  Bounds check both
start and start + count.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
This commit is contained in:
Alex Williamson
2013-03-26 11:33:16 -06:00
committed by Tim Gardner
parent 1ee5641212
commit 1d3555bcaf

View File

@@ -331,6 +331,7 @@ static long vfio_pci_ioctl(void *device_data,
if (!(hdr.flags & VFIO_IRQ_SET_DATA_NONE)) {
size_t size;
int max = vfio_pci_get_irq_count(vdev, hdr.index);
if (hdr.flags & VFIO_IRQ_SET_DATA_BOOL)
size = sizeof(uint8_t);
@@ -340,7 +341,7 @@ static long vfio_pci_ioctl(void *device_data,
return -EINVAL;
if (hdr.argsz - minsz < hdr.count * size ||
hdr.count > vfio_pci_get_irq_count(vdev, hdr.index))
hdr.start >= max || hdr.start + hdr.count > max)
return -EINVAL;
data = memdup_user((void __user *)(arg + minsz),