usb: usb_get_configuration() obeys authorization

If called and the device is not authorized to be used, then we don't
allow reading the configurations.

Signed-off-by: Inaky Perez-Gonzalez <inaky@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 19 insertions, 5 deletions

diff --git a/drivers/usb/core/config.c b/drivers/usb/core/config.c
index cb69aa1e02e8..1a8edcee7f30 100644
--- a/drivers/usb/core/config.c
+++ b/drivers/usb/core/config.c
@@ -507,18 +507,30 @@ void usb_destroy_configuration(struct usb_device *dev)
 }
 
 
-// hub-only!! ... and only in reset path, or usb_new_device()
-// (used by real hubs and virtual root hubs)
+/*
+ * Get the USB config descriptors, cache and parse'em
+ *
+ * hub-only!! ... and only in reset path, or usb_new_device()
+ * (used by real hubs and virtual root hubs)
+ *
+ * NOTE: if this is a WUSB device and is not authorized, we skip the
+ *       whole thing. A non-authorized USB device has no
+ *       configurations.
+ */
 int usb_get_configuration(struct usb_device *dev)
 {
         struct device *ddev = &dev->dev;
         int ncfg = dev->descriptor.bNumConfigurations;
-        int result = -ENOMEM;
+        int result = 0;
         unsigned int cfgno, length;
         unsigned char *buffer;
         unsigned char *bigbuffer;
         struct usb_config_descriptor *desc;
 
+        cfgno = 0;
+        if (dev->authorized == 0)       /* Not really an error */
+                goto out_not_authorized;
+        result = -ENOMEM;
         if (ncfg > USB_MAXCONFIG) {
                 dev_warn(ddev, "too many configurations: %d, "
                     "using maximum allowed: %d\n", ncfg, USB_MAXCONFIG);
@@ -545,14 +557,15 @@ int usb_get_configuration(struct usb_device *dev)
                 goto err2;
         desc = (struct usb_config_descriptor *)buffer;
 
-        for (cfgno = 0; cfgno < ncfg; cfgno++) {
+        result = 0;
+        for (; cfgno < ncfg; cfgno++) {
                 /* We grab just the first descriptor so we know how long
                  * the whole configuration is */
                 result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno,
                     buffer, USB_DT_CONFIG_SIZE);
                 if (result < 0) {
                         dev_err(ddev, "unable to read config index %d "
-                            "descriptor/%s\n", cfgno, "start");
+                            "descriptor/%s: %d\n", cfgno, "start", result);
                         dev_err(ddev, "chopping to %d config(s)\n", cfgno);
                         dev->descriptor.bNumConfigurations = cfgno;
                         break;
@@ -599,6 +612,7 @@ int usb_get_configuration(struct usb_device *dev)
 
 err:
         kfree(buffer);
+out_not_authorized:
         dev->descriptor.bNumConfigurations = cfgno;
 err2:
         if (result == -ENOMEM)