[PATCH 3.14 011/110] Staging: rtl8188eu: overflow in update_sta_support_rate()

Greg Kroah-Hartman
2014-06-28T18:56:48Z

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

commit 9dbd79aeb9842144d9a114a979a12c0949ee11eb upstream.

The ->SupportedRates[] array has NDIS_802_11_LENGTH_RATES_EX (16)
elements. Since "ie_len" comes from then network and can go up to 255
then it means we should add a range check to prevent memory corruption.

Fixes: d6846af679e0 ('staging: r8188eu: Add files for new driver - part 7')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/staging/rtl8188eu/core/rtw_wlan_util.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

--- a/drivers/staging/rtl8188eu/core/rtw_wlan_util.c
+++ b/drivers/staging/rtl8188eu/core/rtw_wlan_util.c
@@ -1601,13 +1601,18 @@ int update_sta_support_rate(struct adapt
pIE = (struct ndis_802_11_var_ie *)rtw_get_ie(pvar_ie, _SUPPORTEDRATES_IE_, &ie_len, var_ie_len);
if (pIE == NULL)
return _FAIL;
+ if (ie_len > NDIS_802_11_LENGTH_RATES_EX)
+ return _FAIL;

memcpy(pmlmeinfo->FW_sta_info[cam_idx].SupportedRates, pIE->data, ie_len);
supportRateNum = ie_len;

pIE = (struct ndis_802_11_var_ie *)rtw_get_ie(pvar_ie, _EXT_SUPPORTEDRATES_IE_, &ie_len, var_ie_len);
- if (pIE)
+ if (pIE) {
+ if (supportRateNum + ie_len > NDIS_802_11_LENGTH_RATES_EX)
+ return _FAIL;
memcpy((pmlmeinfo->FW_sta_info[cam_idx].SupportedRates + supportRateNum), pIE->data, ie_len);
+ }

return _SUCCESS;
}