[PATCH 4.14 82/95] rtlwifi: Fix potential overflow on P2P code

[Greg Kroah-Hartman]

From: Laura Abbott <labbott@xxxxxxxxxx>

commit 8c55dedb795be8ec0cf488f98c03a1c2176f7fb1 upstream.

Nicolas Waisman noticed that even though noa_len is checked for
a compatible length it's still possible to overrun the buffers
of p2pinfo since there's no check on the upper bound of noa_num.
Bound noa_num against P2P_MAX_NOA_NUM.

Reported-by: Nicolas Waisman <nico@xxxxxxxxxx>
Signed-off-by: Laura Abbott <labbott@xxxxxxxxxx>
Acked-by: Ping-Ke Shih <pkshih@xxxxxxxxxxx>
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/net/wireless/realtek/rtlwifi/ps.c |    6 ++++++
 1 file changed, 6 insertions(+)

--- a/drivers/net/wireless/realtek/rtlwifi/ps.c
+++ b/drivers/net/wireless/realtek/rtlwifi/ps.c
@@ -774,6 +774,9 @@ static void rtl_p2p_noa_ie(struct ieee80
 				return;
 			} else {
 				noa_num = (noa_len - 2) / 13;
+				if (noa_num > P2P_MAX_NOA_NUM)
+					noa_num = P2P_MAX_NOA_NUM;
+
 			}
 			noa_index = ie[3];
 			if (rtlpriv->psc.p2p_ps_info.p2p_ps_mode ==
@@ -868,6 +871,9 @@ static void rtl_p2p_action_ie(struct iee
 				return;
 			} else {
 				noa_num = (noa_len - 2) / 13;
+				if (noa_num > P2P_MAX_NOA_NUM)
+					noa_num = P2P_MAX_NOA_NUM;
+
 			}
 			noa_index = ie[3];
 			if (rtlpriv->psc.p2p_ps_info.p2p_ps_mode ==