[PATCH 3.8.y] vfio-pci: Fix possible integer overflow

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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@xxxxxxxxxx>
Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
(cherry picked from commit 904c680c7bf016a8619a045850937427f8d7368c)
---

Applies correctly with fuzz back through 3.6.y.

 drivers/vfio/pci/vfio_pci.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index b28e66c..4a62e12 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -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),

--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]