[PATCH 3.12 101/181] Staging: rtl8188eu: overflow in update_sta_support_rate()

[Jiri Slaby]

From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

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

===============

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@xxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
 drivers/staging/rtl8188eu/core/rtw_wlan_util.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/rtl8188eu/core/rtw_wlan_util.c b/drivers/staging/rtl8188eu/core/rtw_wlan_util.c
index 8018edd3d42e..ce638d1723e3 100644
--- a/drivers/staging/rtl8188eu/core/rtw_wlan_util.c
+++ b/drivers/staging/rtl8188eu/core/rtw_wlan_util.c
@@ -1607,13 +1607,18 @@ int update_sta_support_rate(struct adapter *padapter, u8 *pvar_ie, uint var_ie_l
 	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;
 }
-- 
2.0.0

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