Commit 28962ec5 authored by Jason Wang's avatar Jason Wang Committed by Michael S. Tsirkin

virtio_console: validate max_nr_ports before trying to use it

We calculate nr_ports based on the max_nr_ports:

nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2;

If the device advertises a large max_nr_ports, we will end up with a
integer overflow. Fixing this by validating the max_nr_ports and fail
the probe for invalid max_nr_ports in this case.

Cc: Amit Shah <amit@kernel.org>
Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20211019070152.8236-3-jasowang@redhat.comSigned-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 63b4ffa4
......@@ -28,6 +28,7 @@
#include "../tty/hvc/hvc_console.h"
#define is_rproc_enabled IS_ENABLED(CONFIG_REMOTEPROC)
#define VIRTCONS_MAX_PORTS 0x8000
/*
* This is a global struct for storing common data for all the devices
......@@ -2036,6 +2037,14 @@ static int virtcons_probe(struct virtio_device *vdev)
virtio_cread_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT,
struct virtio_console_config, max_nr_ports,
&portdev->max_nr_ports) == 0) {
if (portdev->max_nr_ports == 0 ||
portdev->max_nr_ports > VIRTCONS_MAX_PORTS) {
dev_err(&vdev->dev,
"Invalidate max_nr_ports %d",
portdev->max_nr_ports);
err = -EINVAL;
goto free;
}
multiport = true;
}
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment