staging: most: usb: check number of reported endpoints

This patch checks the number of endpoints reported by the USB
interface descriptor and throws an error if the number exceeds
MAX_NUM_ENDPOINTS.

Signed-off-by: Christian Gromm <christian.gromm@microchip.com>
Reported-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/1589534465-7423-4-git-send-email-christian.gromm@microchip.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/most/usb/usb.c b/drivers/staging/most/usb/usb.c
index dbb6003..36c277f 100644 (file)
--- a/drivers/staging/most/usb/usb.c
+++ b/drivers/staging/most/usb/usb.c
@@ -950,13 +950,17 @@ hdm_probe(struct usb_interface *interface, const struct usb_device_id *id)
        unsigned int num_endpoints;
        struct most_channel_capability *tmp_cap;
        struct usb_endpoint_descriptor *ep_desc;
-       int ret = 0;
+       int ret = -ENOMEM;
 
        if (!mdev)
-               goto err_out_of_memory;
+               return -ENOMEM;
 
        usb_set_intfdata(interface, mdev);
        num_endpoints = usb_iface_desc->desc.bNumEndpoints;
+       if (num_endpoints > MAX_NUM_ENDPOINTS) {
+               kfree(mdev);
+               return -EINVAL;
+       }
        mutex_init(&mdev->io_mutex);
        INIT_WORK(&mdev->poll_work_obj, wq_netinfo);
        timer_setup(&mdev->link_stat_timer, link_stat_timer_handler, 0);
@@ -1085,11 +1089,6 @@ err_free_conf:
        kfree(mdev->conf);
 err_free_mdev:
        put_device(&mdev->dev);
-err_out_of_memory:
-       if (ret == 0 || ret == -ENOMEM) {
-               ret = -ENOMEM;
-               dev_err(dev, "out of memory\n");
-       }
        return ret;
 }