From 5c677869e0abbffbade2cfd82d46d0eebe823f34 Mon Sep 17 00:00:00 2001 From: Dan Carpenter 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 Reviewed-by: Kirti Wankhede Signed-off-by: Alex Williamson --- 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 975af5bbf28d..382f4797428f 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: -- 2.20.1