usb: core: Fix potential memory leak adding dyn USBdevice IDs

Fix a memory leak in the usb_store_new_id() error paths. When bailing out
due to sanity checks, the function left the already allocated usb_dynid
struct in place. This regression was introduced by the following commits:

c63fe8f6 (usb: core: add sanity checks when using bInterfaceClass with new_id)
1b9fb31f (usb: core: check for valid id_table when using the RefId feature)
52a6966c (usb: core: bail out if user gives an unknown RefId when using new_id)

Detected by Coverity: CID 1162604.

Signed-off-by: Christian Engelmayer <cengelma@gmx.at>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 17 insertions, 7 deletions

diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c
index 5d01558cef66..ab90a0156828 100644
--- a/drivers/usb/core/driver.c
+++ b/drivers/usb/core/driver.c
@@ -63,8 +63,10 @@ ssize_t usb_store_new_id(struct usb_dynids *dynids,
         dynid->id.idProduct = idProduct;
         dynid->id.match_flags = USB_DEVICE_ID_MATCH_DEVICE;
         if (fields > 2 && bInterfaceClass) {
-                if (bInterfaceClass > 255)
-                        return -EINVAL;
+                if (bInterfaceClass > 255) {
+                        retval = -EINVAL;
+                        goto fail;
+                }
 
                 dynid->id.bInterfaceClass = (u8)bInterfaceClass;
                 dynid->id.match_flags |= USB_DEVICE_ID_MATCH_INT_CLASS;
@@ -73,17 +75,21 @@ ssize_t usb_store_new_id(struct usb_dynids *dynids,
         if (fields > 4) {
                 const struct usb_device_id *id = id_table;
 
-                if (!id)
-                        return -ENODEV;
+                if (!id) {
+                        retval = -ENODEV;
+                        goto fail;
+                }
 
                 for (; id->match_flags; id++)
                         if (id->idVendor == refVendor && id->idProduct == refProduct)
                                 break;
 
-                if (id->match_flags)
+                if (id->match_flags) {
                         dynid->id.driver_info = id->driver_info;
-                else
-                        return -ENODEV;
+                } else {
+                        retval = -ENODEV;
+                        goto fail;
+                }
         }
 
         spin_lock(&dynids->lock);
@@ -95,6 +101,10 @@ ssize_t usb_store_new_id(struct usb_dynids *dynids,
         if (retval)
                 return retval;
         return count;
+
+fail:
+        kfree(dynid);
+        return retval;
 }
 EXPORT_SYMBOL_GPL(usb_store_new_id);