diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c
index b0d3bc49c685..57c68efa5ff8 100644
--- a/drivers/net/ppp/ppp_generic.c
+++ b/drivers/net/ppp/ppp_generic.c
@@ -2245,7 +2245,7 @@ ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
  */
 static void __ppp_decompress_proto(struct sk_buff *skb)
 {
-	if (skb->data[0] & 0x01)
+	if (ppp_skb_is_compressed_proto(skb))
 		*(u8 *)skb_push(skb, 1) = 0x00;
 }
 
diff --git a/drivers/net/ppp/pppoe.c b/drivers/net/ppp/pppoe.c
index d546a7af0d54..bdd61c504a1c 100644
--- a/drivers/net/ppp/pppoe.c
+++ b/drivers/net/ppp/pppoe.c
@@ -393,7 +393,7 @@ static int pppoe_rcv(struct sk_buff *skb, struct net_device *dev,
 	if (skb_mac_header_len(skb) < ETH_HLEN)
 		goto drop;
 
-	if (!pskb_may_pull(skb, sizeof(struct pppoe_hdr)))
+	if (!pskb_may_pull(skb, PPPOE_SES_HLEN))
 		goto drop;
 
 	ph = pppoe_hdr(skb);
@@ -403,6 +403,12 @@ static int pppoe_rcv(struct sk_buff *skb, struct net_device *dev,
 	if (skb->len < len)
 		goto drop;
 
+	/* skb->data points to the PPP protocol header after skb_pull_rcsum.
+	 * Drop PFC frames.
+	 */
+	if (ppp_skb_is_compressed_proto(skb))
+		goto drop;
+
 	if (pskb_trim_rcsum(skb, len))
 		goto drop;
 
diff --git a/include/linux/ppp_defs.h b/include/linux/ppp_defs.h
index b7e57fdbd413..b1d1f46d7d3b 100644
--- a/include/linux/ppp_defs.h
+++ b/include/linux/ppp_defs.h
@@ -8,6 +8,7 @@
 #define _PPP_DEFS_H_
 
 #include <linux/crc-ccitt.h>
+#include <linux/skbuff.h>
 #include <uapi/linux/ppp_defs.h>
 
 #define PPP_FCS(fcs, c) crc_ccitt_byte(fcs, c)
@@ -25,4 +26,19 @@ static inline bool ppp_proto_is_valid(u16 proto)
 	return !!((proto & 0x0101) == 0x0001);
 }
 
+/**
+ * ppp_skb_is_compressed_proto - checks if PPP protocol in a skb is compressed
+ * @skb: skb to check
+ *
+ * Check if the PPP protocol field is compressed (the least significant
+ * bit of the most significant octet is 1). skb->data must point to the PPP
+ * protocol header.
+ *
+ * Return: Whether the PPP protocol field is compressed.
+ */
+static inline bool ppp_skb_is_compressed_proto(const struct sk_buff *skb)
+{
+	return unlikely(skb->data[0] & 0x01);
+}
+
 #endif /* _PPP_DEFS_H_ */