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>
diff --git a/drivers/net/wireless/rndis_wlan.c b/drivers/net/wireless/rndis_wlan.c
index a330c69..dde45ef 100644
--- a/drivers/net/wireless/rndis_wlan.c
+++ b/drivers/net/wireless/rndis_wlan.c
@@ -2755,9 +2755,10 @@
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 @@
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 @@
}
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)