From: Jiyoung Jeong <ji_0.jeong@samsung.com>
Date: Thu, 28 Feb 2019 01:06:44 +0000 (+0900)
Subject: [RAMEN9610-12695][COMMON][MODAP-20423] fix L2TP cfi_check_fail issue
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=687b613efd0b0bdcef64760ae5562e542a7f27c2;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git

[RAMEN9610-12695][COMMON][MODAP-20423] fix L2TP cfi_check_fail issue

Change-Id: I9b517321289235d60d44f6f814a7a6c96235836e
Signed-off-by: Jiyoung Jeong <ji_0.jeong@samsung.com>
---

diff --git a/drivers/net/ppp/pppolac.c b/drivers/net/ppp/pppolac.c
index 95cc6be54ad5..14cdf07294f4 100644
--- a/drivers/net/ppp/pppolac.c
+++ b/drivers/net/ppp/pppolac.c
@@ -47,6 +47,8 @@
 #define PPP_ADDR	0xFF
 #define PPP_CTRL	0x03
 
+#define NET_RX_L2TP_CONTROL_MSG	2
+
 union unaligned {
 	__u32 u32;
 } __attribute__((packed));
@@ -82,8 +84,12 @@ static int pppolac_recv_core(struct sock *sk_udp, struct sk_buff *skb)
 		goto drop;
 
 	/* Put it back if it is a control packet. */
-	if (skb->data[sizeof(struct udphdr)] & L2TP_CONTROL_BIT)
+	if (skb->data[sizeof(struct udphdr)] & L2TP_CONTROL_BIT) {
+		if (!opt->backlog_rcv)
+			return NET_RX_L2TP_CONTROL_MSG;
+
 		return opt->backlog_rcv(sk_udp, skb);
+	}
 
 	/* Skip UDP header. */
 	skb_pull(skb, sizeof(struct udphdr));
@@ -190,8 +196,13 @@ drop:
 
 static int pppolac_recv(struct sock *sk_udp, struct sk_buff *skb)
 {
+	int ret = 0;
+
 	sock_hold(sk_udp);
-	sk_receive_skb(sk_udp, skb, 0);
+	ret = sk_receive_skb(sk_udp, skb, 0);
+	if (ret == NET_RX_L2TP_CONTROL_MSG)
+		return 1;
+
 	return 0;
 }