svn commit: r348894 - stable/12/lib/libusb

[Hans Petter Selasky]

Author: hselasky
Date: Tue Jun 11 08:52:48 2019
New Revision: 348894
URL: https://svnweb.freebsd.org/changeset/base/348894

Log:
  MFC r348797:
  Fix for reading the configuration descriptor in libusb. Catch invalid
  configuration descriptor reads early on to avoid issues with devices
  that don't check for a valid USB configuration read request.
  
  Submitted by:	takahiro.kurosawa at gmail.com
  PR:		238412

Modified:
  stable/12/lib/libusb/libusb20.c
Directory Properties:
  stable/12/   (props changed)

Modified: stable/12/lib/libusb/libusb20.c
==============================================================================
--- stable/12/lib/libusb/libusb20.c	Tue Jun 11 08:50:26 2019	(r348893)
+++ stable/12/lib/libusb/libusb20.c	Tue Jun 11 08:52:48 2019	(r348894)
@@ -955,6 +955,14 @@ libusb20_dev_alloc_config(struct libusb20_device *pdev
 	uint8_t do_close;
 	int error;
 
+	/*
+	 * Catch invalid configuration descriptor reads early on to
+	 * avoid issues with devices that don't check for a valid USB
+	 * configuration read request.
+	 */
+	if (configIndex >= pdev->ddesc.bNumConfigurations)
+		return (NULL);
+
 	if (!pdev->is_opened) {
 		error = libusb20_dev_open(pdev, 0);
 		if (error) {