diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2018-07-17 12:39:00 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-07-25 11:25:08 +0200 |
| commit | a5b8eae536723d3377d21fe60cb2f294332bb322 (patch) | |
| tree | e34bed142e1176041f49ae7af016b0818e728518 /drivers/vfio | |
| parent | dfc328156ddea2385394240c373a49bb42320b4c (diff) | |
| download | linux-stable-a5b8eae536723d3377d21fe60cb2f294332bb322.tar.gz linux-stable-a5b8eae536723d3377d21fe60cb2f294332bb322.tar.bz2 linux-stable-a5b8eae536723d3377d21fe60cb2f294332bb322.zip | |
vfio/pci: Fix potential Spectre v1
commit 0e714d27786ce1fb3efa9aac58abc096e68b1c2a upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/vfio')
| -rw-r--r-- | drivers/vfio/pci/vfio_pci.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index f041b1a6cf66..695b9d1a1aae 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" @@ -746,6 +747,9 @@ 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; |