[IPV4]: Do pskb_may_pull in arp_rcv() not arp_process().

net/ipv4/arp.c

@@ -630,12 +630,6 @@ int arp_process(struct sk_buff *skb)
 	if (in_dev == NULL)
 		goto out;
 
-	/* ARP header, plus 2 device addresses, plus 2 IP addresses.  */
-	if (!pskb_may_pull(skb, (sizeof(struct arphdr) +
-				 (2 * dev->addr_len) +
-				 (2 * sizeof(u32)))))
-		goto out;
-
 	arp = skb->nh.arph;
 
 	switch (dev_type) {
@@ -837,6 +831,12 @@ int arp_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt)
 {
 	struct arphdr *arp = skb->nh.arph;
 
+	/* ARP header, plus 2 device addresses, plus 2 IP addresses.  */
+	if (!pskb_may_pull(skb, (sizeof(struct arphdr) +
+				 (2 * dev->addr_len) +
+				 (2 * sizeof(u32)))))
+		goto freeskb;
+
 	if (arp->ar_hln != dev->addr_len ||
 	    dev->flags & IFF_NOARP ||
 	    skb->pkt_type == PACKET_OTHERHOST ||