1 files changed, 10 insertions, 18 deletions

diff --git a/net/ipv4/netfilter/arpt_mangle.c b/net/ipv4/netfilter/arpt_mangle.c
index c4bdab47597..45fa4e20094 100644
--- a/net/ipv4/netfilter/arpt_mangle.c
+++ b/net/ipv4/netfilter/arpt_mangle.c
@@ -1,5 +1,6 @@
 /* module that allows mangling of the arp payload */
 #include <linux/module.h>
+#include <linux/netfilter.h>
 #include <linux/netfilter_arp/arpt_mangle.h>
 #include <net/sock.h>
 
@@ -8,7 +9,7 @@ MODULE_AUTHOR("Bart De Schuymer <bdschuym@pandora.be>");
 MODULE_DESCRIPTION("arptables arp payload mangle target");
 
 static unsigned int
-target(struct sk_buff **pskb,
+target(struct sk_buff *skb,
        const struct net_device *in, const struct net_device *out,
        unsigned int hooknum, const struct xt_target *target,
        const void *targinfo)
@@ -18,47 +19,38 @@ target(struct sk_buff **pskb,
 	unsigned char *arpptr;
 	int pln, hln;
 
-	if (skb_shared(*pskb) || skb_cloned(*pskb)) {
-		struct sk_buff *nskb;
+	if (skb_make_writable(skb, skb->len))
+		return NF_DROP;
 
-		nskb = skb_copy(*pskb, GFP_ATOMIC);
-		if (!nskb)
-			return NF_DROP;
-		if ((*pskb)->sk)
-			skb_set_owner_w(nskb, (*pskb)->sk);
-		kfree_skb(*pskb);
-		*pskb = nskb;
-	}
-
-	arp = arp_hdr(*pskb);
-	arpptr = skb_network_header(*pskb) + sizeof(*arp);
+	arp = arp_hdr(skb);
+	arpptr = skb_network_header(skb) + sizeof(*arp);
 	pln = arp->ar_pln;
 	hln = arp->ar_hln;
 	/* We assume that pln and hln were checked in the match */
 	if (mangle->flags & ARPT_MANGLE_SDEV) {
 		if (ARPT_DEV_ADDR_LEN_MAX < hln ||
-		   (arpptr + hln > skb_tail_pointer(*pskb)))
+		   (arpptr + hln > skb_tail_pointer(skb)))
 			return NF_DROP;
 		memcpy(arpptr, mangle->src_devaddr, hln);
 	}
 	arpptr += hln;
 	if (mangle->flags & ARPT_MANGLE_SIP) {
 		if (ARPT_MANGLE_ADDR_LEN_MAX < pln ||
-		   (arpptr + pln > skb_tail_pointer(*pskb)))
+		   (arpptr + pln > skb_tail_pointer(skb)))
 			return NF_DROP;
 		memcpy(arpptr, &mangle->u_s.src_ip, pln);
 	}
 	arpptr += pln;
 	if (mangle->flags & ARPT_MANGLE_TDEV) {
 		if (ARPT_DEV_ADDR_LEN_MAX < hln ||
-		   (arpptr + hln > skb_tail_pointer(*pskb)))
+		   (arpptr + hln > skb_tail_pointer(skb)))
 			return NF_DROP;
 		memcpy(arpptr, mangle->tgt_devaddr, hln);
 	}
 	arpptr += hln;
 	if (mangle->flags & ARPT_MANGLE_TIP) {
 		if (ARPT_MANGLE_ADDR_LEN_MAX < pln ||
-		   (arpptr + pln > skb_tail_pointer(*pskb)))
+		   (arpptr + pln > skb_tail_pointer(skb)))
 			return NF_DROP;
 		memcpy(arpptr, &mangle->u_t.tgt_ip, pln);
 	}