From 5c677869e0abbffbade2cfd82d46d0eebe823f34 Mon Sep 17 00:00:00 2001
From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Sat, 7 Jan 2017 09:28:40 +0300
Subject: [PATCH] vfio-mdev: buffer overflow in ioctl()
This is a sample driver for documentation so the impact is probably
pretty low. But we should check that bar_index is valid so we
don't write beyond the end of the mdev_state->region_info[] array.
Fixes: 9d1a546c53b4 ("docs: Sample driver to demonstrate how to use Mediated device framework.")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
---
samples/vfio-mdev/mtty.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/samples/vfio-mdev/mtty.c b/samples/vfio-mdev/mtty.c
index 975af5bbf28d3..382f4797428f5 100644
--- a/samples/vfio-mdev/mtty.c
+++ b/samples/vfio-mdev/mtty.c
@@ -1073,7 +1073,7 @@ int mtty_get_region_info(struct mdev_device *mdev,
{
unsigned int size = 0;
struct mdev_state *mdev_state;
- int bar_index;
+ u32 bar_index;
if (!mdev)
return -EINVAL;
@@ -1082,8 +1082,11 @@ int mtty_get_region_info(struct mdev_device *mdev,
if (!mdev_state)
return -EINVAL;
- mutex_lock(&mdev_state->ops_lock);
bar_index = region_info->index;
+ if (bar_index >= VFIO_PCI_NUM_REGIONS)
+ return -EINVAL;
+
+ mutex_lock(&mdev_state->ops_lock);
switch (bar_index) {
case VFIO_PCI_CONFIG_REGION_INDEX:
--
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