1 files changed, 15 insertions, 10 deletions

diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index e5b6d0ddcb58..cc1da6d9cb35 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -372,7 +372,7 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
 		goto err;
 
 	err = -ENOMEM;
-	if (pskb_pull(skb, ihl) == NULL)
+	if (!pskb_pull(skb, ihl))
 		goto err;
 
 	err = pskb_trim_rcsum(skb, end - offset);
@@ -537,7 +537,7 @@ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
 		qp->q.fragments = head;
 	}
 
-	WARN_ON(head == NULL);
+	WARN_ON(!head);
 	WARN_ON(FRAG_CB(head)->offset != 0);
 
 	/* Allocate a new buffer for the datagram. */
@@ -559,7 +559,8 @@ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
 		struct sk_buff *clone;
 		int i, plen = 0;
 
-		if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL)
+		clone = alloc_skb(0, GFP_ATOMIC);
+		if (!clone)
 			goto out_nomem;
 		clone->next = head->next;
 		head->next = clone;
@@ -638,7 +639,8 @@ int ip_defrag(struct sk_buff *skb, u32 user)
 	IP_INC_STATS_BH(net, IPSTATS_MIB_REASMREQDS);
 
 	/* Lookup (or create) queue header */
-	if ((qp = ip_find(net, ip_hdr(skb), user)) != NULL) {
+	qp = ip_find(net, ip_hdr(skb), user);
+	if (qp) {
 		int ret;
 
 		spin_lock(&qp->q.lock);
@@ -659,27 +661,30 @@ EXPORT_SYMBOL(ip_defrag);
 struct sk_buff *ip_check_defrag(struct sk_buff *skb, u32 user)
 {
 	struct iphdr iph;
+	int netoff;
 	u32 len;
 
 	if (skb->protocol != htons(ETH_P_IP))
 		return skb;
 
-	if (!skb_copy_bits(skb, 0, &iph, sizeof(iph)))
+	netoff = skb_network_offset(skb);
+
+	if (skb_copy_bits(skb, netoff, &iph, sizeof(iph)) < 0)
 		return skb;
 
 	if (iph.ihl < 5 || iph.version != 4)
 		return skb;
 
 	len = ntohs(iph.tot_len);
-	if (skb->len < len || len < (iph.ihl * 4))
+	if (skb->len < netoff + len || len < (iph.ihl * 4))
 		return skb;
 
 	if (ip_is_fragment(&iph)) {
 		skb = skb_share_check(skb, GFP_ATOMIC);
 		if (skb) {
-			if (!pskb_may_pull(skb, iph.ihl*4))
+			if (!pskb_may_pull(skb, netoff + iph.ihl * 4))
 				return skb;
-			if (pskb_trim_rcsum(skb, len))
+			if (pskb_trim_rcsum(skb, netoff + len))
 				return skb;
 			memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
 			if (ip_defrag(skb, user))
@@ -751,7 +756,7 @@ static int __net_init ip4_frags_ns_ctl_register(struct net *net)
 	table = ip4_frags_ns_ctl_table;
 	if (!net_eq(net, &init_net)) {
 		table = kmemdup(table, sizeof(ip4_frags_ns_ctl_table), GFP_KERNEL);
-		if (table == NULL)
+		if (!table)
 			goto err_alloc;
 
 		table[0].data = &net->ipv4.frags.high_thresh;
@@ -767,7 +772,7 @@ static int __net_init ip4_frags_ns_ctl_register(struct net *net)
 	}
 
 	hdr = register_net_sysctl(net, "net/ipv4", table);
-	if (hdr == NULL)
+	if (!hdr)
 		goto err_reg;
 
 	net->ipv4.frags_hdr = hdr;