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 <[email protected]> Signed-off-by: Jason Wang <[email protected]> --- drivers/char/virtio_console.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index 7eaf303a7a86..660c5c388c29 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -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; } -- 2.25.1 _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
