vendor/unbound/1.6.4

1 files changed, 9 insertions, 3 deletions

diff --git a/util/data/msgencode.c b/util/data/msgencode.c
index 1f72a03b8c64..aab7f5dfecba 100644
--- a/util/data/msgencode.c
+++ b/util/data/msgencode.c
@@ -647,6 +647,8 @@ reply_info_encode(struct query_info* qinfo, struct reply_info* rep,
 	sldns_buffer_clear(buffer);
 	if(udpsize < sldns_buffer_limit(buffer))
 		sldns_buffer_set_limit(buffer, udpsize);
+	else if(sldns_buffer_limit(buffer) < udpsize)
+		udpsize = sldns_buffer_limit(buffer);
 	if(sldns_buffer_remaining(buffer) < LDNS_HEADER_SIZE)
 		return 0;
 
@@ -810,7 +812,7 @@ reply_info_answer_encode(struct query_info* qinf, struct reply_info* rep,
 	struct edns_data* edns, int dnssec, int secure)
 {
 	uint16_t flags;
-	int attach_edns = 1;
+	unsigned int attach_edns = 0;
 
 	if(!cached || rep->authoritative) {
 		/* original flags, copy RD and CD bits from query. */
@@ -833,12 +835,15 @@ reply_info_answer_encode(struct query_info* qinf, struct reply_info* rep,
 	log_assert(flags & BIT_QR); /* QR bit must be on in our replies */
 	if(udpsize < LDNS_HEADER_SIZE)
 		return 0;
+	if(sldns_buffer_capacity(pkt) < udpsize)
+		udpsize = sldns_buffer_capacity(pkt);
 	if(udpsize < LDNS_HEADER_SIZE + calc_edns_field_size(edns)) {
 		/* packet too small to contain edns, omit it. */
 		attach_edns = 0;
 	} else {
 		/* reserve space for edns record */
-		udpsize -= calc_edns_field_size(edns);
+		attach_edns = (unsigned int)calc_edns_field_size(edns);
+		udpsize -= attach_edns;
 	}
 
 	if(!reply_info_encode(qinf, rep, id, flags, pkt, timenow, region,
@@ -846,7 +851,8 @@ reply_info_answer_encode(struct query_info* qinf, struct reply_info* rep,
 		log_err("reply encode: out of memory");
 		return 0;
 	}
-	if(attach_edns)
+	if(attach_edns && sldns_buffer_capacity(pkt) >=
+		sldns_buffer_limit(pkt)+attach_edns)
 		attach_edns_record(pkt, edns);
 	return 1;
 }