[PATCH 33/75] USB: cxacru: potential underflow in cxacru_cm_get_array()

[Kamal Mostafa]

3.8.13.2 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dan Carpenter <dan.carpenter at oracle.com>

commit 2a0ebf80aa95cc758d4725f74a7016e992606a39 upstream.

The value of "offd" comes off the instance->rcv_buf[] and we used it as
the offset into an array.  The problem is that we check the upper bound
but not for negative values.

Signed-off-by: Dan Carpenter <dan.carpenter at oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/usb/atm/cxacru.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/atm/cxacru.c b/drivers/usb/atm/cxacru.c
index b7eb86a..8a7eb77 100644
--- a/drivers/usb/atm/cxacru.c
+++ b/drivers/usb/atm/cxacru.c
@@ -686,7 +686,8 @@ static int cxacru_cm_get_array(struct cxacru_data *instance, enum cxacru_cm_requ
 {
 	int ret, len;
 	__le32 *buf;
-	int offb, offd;
+	int offb;
+	unsigned int offd;
 	const int stride = CMD_PACKET_SIZE / (4 * 2) - 1;
 	int buflen =  ((size - 1) / stride + 1 + size * 2) * 4;
 
-- 
1.8.1.2