1 files changed, 3 insertions, 4 deletions

diff --git a/sys/kern/uipc_sockbuf.c b/sys/kern/uipc_sockbuf.c
index c1072b7eeaa1..93d1fdacec5a 100644
--- a/sys/kern/uipc_sockbuf.c
+++ b/sys/kern/uipc_sockbuf.c
@@ -839,16 +839,15 @@ sbcreatecontrol(p, size, type, level)
 	register struct cmsghdr *cp;
 	struct mbuf *m;
 
-	if ((u_int)size > MLEN)
+	if (CMSG_SPACE((u_int)size) > MLEN)
 		return ((struct mbuf *) NULL);
 	if ((m = m_get(M_DONTWAIT, MT_CONTROL)) == NULL)
 		return ((struct mbuf *) NULL);
 	cp = mtod(m, struct cmsghdr *);
 	/* XXX check size? */
 	(void)memcpy(CMSG_DATA(cp), p, size);
-	size += sizeof(*cp);
-	m->m_len = size;
-	cp->cmsg_len = size;
+	m->m_len = CMSG_SPACE(size);
+	cp->cmsg_len = CMSG_LEN(size);
 	cp->cmsg_level = level;
 	cp->cmsg_type = type;
 	return (m);