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authorGustavo A. R. Silva <gustavo@embeddedor.com>2018-07-17 12:39:00 -0500
committerAlex Williamson <alex.williamson@redhat.com>2018-07-18 12:57:25 -0600
commit0e714d27786ce1fb3efa9aac58abc096e68b1c2a (patch)
tree0d46cee8004e651a4cab9262d43373f630c23026 /drivers/vfio
parent9d3cce1e8b8561fed5f383d22a4d6949db4eadbe (diff)
downloadlinux-0e714d27786ce1fb3efa9aac58abc096e68b1c2a.tar.bz2
vfio/pci: Fix potential Spectre v1
info.index can be indirectly controlled by user-space, hence leading to a potential exploitation of the Spectre variant 1 vulnerability. This issue was detected with the help of Smatch: drivers/vfio/pci/vfio_pci.c:734 vfio_pci_ioctl() warn: potential spectre issue 'vdev->region' Fix this by sanitizing info.index before indirectly using it to index vdev->region Notice that given that speculation windows are large, the policy is to kill the speculation on the first load and not worry if it can be completed with a dependent load/store [1]. [1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2 Cc: stable@vger.kernel.org Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Diffstat (limited to 'drivers/vfio')
-rw-r--r--drivers/vfio/pci/vfio_pci.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index b423a309a6e0..125b58eff936 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -28,6 +28,7 @@
#include <linux/uaccess.h>
#include <linux/vfio.h>
#include <linux/vgaarb.h>
+#include <linux/nospec.h>
#include "vfio_pci_private.h"
@@ -727,6 +728,9 @@ static long vfio_pci_ioctl(void *device_data,
if (info.index >=
VFIO_PCI_NUM_REGIONS + vdev->num_regions)
return -EINVAL;
+ info.index = array_index_nospec(info.index,
+ VFIO_PCI_NUM_REGIONS +
+ vdev->num_regions);
i = info.index - VFIO_PCI_NUM_REGIONS;