From: Simon Arlott <simon@fire.lp0.eu>
Date: Sat, 21 Nov 2009 15:07:14 +0000 (+0000)
Subject: USB: cxacru: check data length is not negative
X-Git-Tag: v2.6.34-rc1~215^2~215
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=5d0a9c7932c45435de72b5a5b2825c7eb34186a4;p=profile%2Fivi%2Fkernel-x86-ivi.git

USB: cxacru: check data length is not negative

When attempting to read data that is not actually
an array of values, the length may be negative
which causes an Oops due to a likely access off
the end of the data array.

This bug should not occur under normal use unless
the device returns an invalid response.

Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/drivers/usb/atm/cxacru.c b/drivers/usb/atm/cxacru.c
index 4a26a6c..8da4a06 100644
--- a/drivers/usb/atm/cxacru.c
+++ b/drivers/usb/atm/cxacru.c
@@ -596,7 +596,7 @@ static int cxacru_cm_get_array(struct cxacru_data *instance, enum cxacru_cm_requ
 	len = ret / 4;
 	for (offb = 0; offb < len; ) {
 		int l = le32_to_cpu(buf[offb++]);
-		if (l > stride || l > (len - offb) / 2) {
+		if (l < 0 || l > stride || l > (len - offb) / 2) {
 			if (printk_ratelimit())
 				usb_err(instance->usbatm, "invalid data length from cm %#x: %d\n",
 					cm, l);