- xfr-tsig, test buffer size.

diff --git a/util/tsig.c b/util/tsig.c
index 7a82848d372bc9824d2a777ded004ae45e75ba28..18c04a3b4b68d8d46e2606858b04b101e00a983c 100644 (file)
--- a/util/tsig.c
+++ b/util/tsig.c
@@ -771,6 +771,13 @@ tsig_sign_query(struct tsig_data* tsig, struct sldns_buffer* pkt,
         * u16 fudge, u16 error, u16 other_len, <data> other_data. */
        /* That fits in the current buffer, since the reserved space for
         * the TSIG record is larger. */
+       if(!sldns_buffer_available(pkt, tsig->key_name_len + 2 + 4
+               + key->algo->wireformat_name_len + 6 + 2 + 2
+               + 2 + tsig->other_len)) {
+               /* Buffer is too small */
+               lock_rw_unlock(&key_table->lock);
+               return 0;
+       }
 
        /* Write uncompressed TSIG owner, it is the key name. */
        sldns_buffer_write(pkt, tsig->key_name, tsig->key_name_len);