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@xxxxxxxxxx>
Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
---
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
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