diff --git a/net/netfilter/nf_conntrack_proto_sctp.c b/net/netfilter/nf_conntrack_proto_sctp.c
index 945dd40e7077..011d414038ea 100644
--- a/net/netfilter/nf_conntrack_proto_sctp.c
+++ b/net/netfilter/nf_conntrack_proto_sctp.c
@@ -142,10 +142,11 @@ static void sctp_print_conntrack(struct seq_file *s, struct nf_conn *ct)
 }
 #endif
 
+/* do_basic_checks ensures sch->length > 0, do not use before */
 #define for_each_sctp_chunk(skb, sch, _sch, offset, dataoff, count)	\
 for ((offset) = (dataoff) + sizeof(struct sctphdr), (count) = 0;	\
-	((sch) = skb_header_pointer((skb), (offset), sizeof(_sch), &(_sch))) &&	\
-	(sch)->length;	\
+	(offset) < (skb)->len &&					\
+	((sch) = skb_header_pointer((skb), (offset), sizeof(_sch), &(_sch)));	\
 	(offset) += (ntohs((sch)->length) + 3) & ~3, (count)++)
 
 /* Some validity checks to make sure the chunks are fine */