static int key_notify_sa_expire(struct xfrm_state *x, const struct km_event *c)
{
	struct sk_buff *out_skb;
	struct sadb_msg *out_hdr;
	int hard;
	int hsc;

	hard = c->data.hard;
	if (hard)
		hsc = 2;
	else
		hsc = 1;

	out_skb = pfkey_xfrm_state2msg_expire(x, hsc);
	if (IS_ERR(out_skb))
		return PTR_ERR(out_skb);

	out_hdr = (struct sadb_msg *) out_skb->data;
	out_hdr->sadb_msg_version = PF_KEY_V2;
	out_hdr->sadb_msg_type = SADB_EXPIRE;
	out_hdr->sadb_msg_satype = pfkey_proto2satype(x->id.proto);
	out_hdr->sadb_msg_errno = 0;
	out_hdr->sadb_msg_reserved = 0;
	out_hdr->sadb_msg_seq = 0;
	out_hdr->sadb_msg_pid = 0;

	pfkey_broadcast(out_skb, GFP_ATOMIC, BROADCAST_REGISTERED, NULL, xs_net(x));
	return 0;
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.