rndis_wlan: integer overflows in rndis_wlan_do_link_up_work()

If "offset" is negative then we can get past this check:
	if (offset > CONTROL_BUFFER_SIZE)
Or if we pick a very high "req_ie_len" then we can get around the check:
	if (offset + req_ie_len > CONTROL_BUFFER_SIZE)

I made "resp_ie_len" and "req_ie_len" unsigned.  I don't know if it was
intentional that they were signed in the original.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Dan Carpenter 2012-03-01 10:02:08 +03:00 committed by John W. Linville
parent 5533513784
commit 41eedf39df

View file

@ -2755,9 +2755,10 @@ static void rndis_wlan_do_link_up_work(struct usbnet *usbdev)
struct rndis_wlan_private *priv = get_rndis_wlan_priv(usbdev);
struct ndis_80211_assoc_info *info = NULL;
u8 bssid[ETH_ALEN];
int resp_ie_len, req_ie_len;
unsigned int resp_ie_len, req_ie_len;
unsigned int offset;
u8 *req_ie, *resp_ie;
int ret, offset;
int ret;
bool roamed = false;
bool match_bss;
@ -2785,7 +2786,9 @@ static void rndis_wlan_do_link_up_work(struct usbnet *usbdev)
ret = get_association_info(usbdev, info, CONTROL_BUFFER_SIZE);
if (!ret) {
req_ie_len = le32_to_cpu(info->req_ie_length);
if (req_ie_len > 0) {
if (req_ie_len > CONTROL_BUFFER_SIZE)
req_ie_len = CONTROL_BUFFER_SIZE;
if (req_ie_len != 0) {
offset = le32_to_cpu(info->offset_req_ies);
if (offset > CONTROL_BUFFER_SIZE)
@ -2799,7 +2802,9 @@ static void rndis_wlan_do_link_up_work(struct usbnet *usbdev)
}
resp_ie_len = le32_to_cpu(info->resp_ie_length);
if (resp_ie_len > 0) {
if (resp_ie_len > CONTROL_BUFFER_SIZE)
resp_ie_len = CONTROL_BUFFER_SIZE;
if (resp_ie_len != 0) {
offset = le32_to_cpu(info->offset_resp_ies);
if (offset > CONTROL_BUFFER_SIZE)