Re: [PATCH] USB: don't read past config->interface[] if usb_control_msg() fails in usb_reset_configuration()

[Roel Kluin <roel.kluin@gmail.com>]

After the loop `for (i = 0; i < config->desc.bNumInterfaces; i++)' if no
break occurred, i equals config->desc.bNumInterfaces. so if
usb_control_msg() failed then after goto reset_old_alts we read from
config->interface[config->desc.bNumInterfaces].
We can safely decrement i as well if the break occurred.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
---

> You correctly identified a problem, but your fix is wrong -- or at 
> least, it is much too complicated.

Ok,

 drivers/usb/core/message.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index 9bc95fe..1a48aac 100644
--- 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;