- /* We found where to put this one. Check for overlap with
- * preceding fragment, and, if needed, align things so that
- * any overlaps are eliminated.
- */
- if (prev) {
- int i = (NFCT_FRAG6_CB(prev)->offset + prev->len) - offset;
-
- if (i > 0) {
- offset += i;
- if (end <= offset) {
- pr_debug("overlap\n");
- goto err;
- }
- if (!pskb_pull(skb, i)) {
- pr_debug("Can't pull\n");
- goto err;
- }
- if (skb->ip_summed != CHECKSUM_UNNECESSARY)
- skb->ip_summed = CHECKSUM_NONE;
- }
- }
-
- /* Look for overlap with succeeding segments.
- * If we can merge fragments, do it.
+ /* RFC5722, Section 4:
+ * When reassembling an IPv6 datagram, if
+ * one or more its constituent fragments is determined to be an
+ * overlapping fragment, the entire datagram (and any constituent
+ * fragments, including those not yet received) MUST be silently
+ * discarded.