USB: don't read past config->interface[] if usb_control_msg() fails in usb_reset_conf...

commit e4a3d94658b5760fc947d7f7185c57db47ca362a upstream.

While looping over the interfaces, if usb_hcd_alloc_bandwidth() fails it calls
hcd->driver->reset_bandwidth(), so there was no need to reinstate the interface
again.

If no break occurred, the index equals config->desc.bNumInterfaces. A
subsequent usb_control_msg() failure resulted in a read from
config->interface[config->desc.bNumInterfaces] at label reset_old_alts.

In either case the last interface should be skipped.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index 9bc95fec793fa674727d19c53820853c128afabb..1a48aac6d3bf903730bdaa6bb4f75838afd08ab5 100644 (file)
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -1471,7 +1471,7 @@ int usb_reset_configuration(struct usb_device *dev)
        /* If not, reinstate the old alternate settings */
        if (retval < 0) {
 reset_old_alts:
-               for (; i >= 0; i--) {
+               for (i--; i >= 0; i--) {
                        struct usb_interface *intf = config->interface[i];
                        struct usb_host_interface *alt;