diff --git a/CHANGES b/CHANGES index 9b52c5a5b9..5d302245a3 100644 --- a/CHANGES +++ b/CHANGES @@ -1,3 +1,8 @@ +4260. [security] Insufficient testing when parsing a message allowed + records with an incorrect class to be be accepted, + triggering a REQUIRE failure when those records + were subsequently cached. (CVE-2015-8000) [RT #4098] + 4258. [bug] Limit rndc query message sizes to 32 KiB. This should not break any legitimate rndc commands, but will prevent a rogue rndc query from allocating too diff --git a/bin/tests/system/start.pl b/bin/tests/system/start.pl index 272f5396f0..4d1816fa93 100644 --- a/bin/tests/system/start.pl +++ b/bin/tests/system/start.pl @@ -68,6 +68,7 @@ my $NAMED = $ENV{'NAMED'}; my $LWRESD = $ENV{'LWRESD'}; my $DIG = $ENV{'DIG'}; my $PERL = $ENV{'PERL'}; +my $PYTHON = $ENV{'PYTHON'}; # Start the server(s) @@ -226,7 +227,9 @@ sub start_server { $pid_file = "lwresd.pid"; } elsif ($server =~ /^ans/) { $cleanup_files = "{ans.run}"; - if (-e "$testdir/$server/ans.pl") { + if (-e "$testdir/$server/ans.py") { + $command = "$PYTHON ans.py 10.53.0.$' 5300"; + } elsif (-e "$testdir/$server/ans.pl") { $command = "$PERL ans.pl"; } else { $command = "$PERL $topdir/ans.pl 10.53.0.$'"; diff --git a/doc/arm/notes.xml b/doc/arm/notes.xml index 355a39a906..ea2ecb0068 100644 --- a/doc/arm/notes.xml +++ b/doc/arm/notes.xml @@ -40,6 +40,15 @@
Security Fixes + + + Insufficient testing when parsing a message allowed + records with an incorrect class to be be accepted, + triggering a REQUIRE failure when those records + were subsequently cached. This flaw is disclosed + in CVE-2015-8000. [RT #4098] + + An incorrect boundary check in the OPENPGPKEY rdatatype diff --git a/lib/dns/include/dns/message.h b/lib/dns/include/dns/message.h index 76f78bfdfb..395d066a48 100644 --- a/lib/dns/include/dns/message.h +++ b/lib/dns/include/dns/message.h @@ -15,8 +15,6 @@ * PERFORMANCE OF THIS SOFTWARE. */ -/* $Id$ */ - #ifndef DNS_MESSAGE_H #define DNS_MESSAGE_H 1 @@ -216,6 +214,8 @@ struct dns_message { unsigned int verify_attempted : 1; unsigned int free_query : 1; unsigned int free_saved : 1; + unsigned int tkey : 1; + unsigned int rdclass_set : 1; unsigned int opt_reserved; unsigned int sig_reserved; @@ -1380,6 +1380,15 @@ dns_message_buildopt(dns_message_t *msg, dns_rdataset_t **opt, * \li other. */ +void +dns_message_setclass(dns_message_t *msg, dns_rdataclass_t rdclass); +/*%< + * Set the expected class of records in the response. + * + * Requires: + * \li msg be a valid message with parsing intent. + */ + ISC_LANG_ENDDECLS #endif /* DNS_MESSAGE_H */ diff --git a/lib/dns/message.c b/lib/dns/message.c index a3e1230af5..d4def431a1 100644 --- a/lib/dns/message.c +++ b/lib/dns/message.c @@ -438,6 +438,8 @@ msginit(dns_message_t *m) { m->saved.base = NULL; m->saved.length = 0; m->free_saved = 0; + m->tkey = 0; + m->rdclass_set = 0; m->querytsig = NULL; } @@ -1088,12 +1090,18 @@ getquestions(isc_buffer_t *source, dns_message_t *msg, dns_decompress_t *dctx, * If this class is different than the one we already read, * this is an error. */ - if (msg->state == DNS_SECTION_ANY) { - msg->state = DNS_SECTION_QUESTION; + if (msg->rdclass_set == 0) { msg->rdclass = rdclass; + msg->rdclass_set = 1; } else if (msg->rdclass != rdclass) DO_FORMERR; + /* + * Is this a TKEY query? + */ + if (rdtype == dns_rdatatype_tkey) + msg->tkey = 1; + /* * Can't ask the same question twice. */ @@ -1238,12 +1246,12 @@ getsection(isc_buffer_t *source, dns_message_t *msg, dns_decompress_t *dctx, * If there was no question section, we may not yet have * established a class. Do so now. */ - if (msg->state == DNS_SECTION_ANY && + if (msg->rdclass_set == 0 && rdtype != dns_rdatatype_opt && /* class is UDP SIZE */ rdtype != dns_rdatatype_tsig && /* class is ANY */ rdtype != dns_rdatatype_tkey) { /* class is undefined */ msg->rdclass = rdclass; - msg->state = DNS_SECTION_QUESTION; + msg->rdclass_set = 1; } /* @@ -1253,13 +1261,23 @@ getsection(isc_buffer_t *source, dns_message_t *msg, dns_decompress_t *dctx, if (msg->opcode != dns_opcode_update && rdtype != dns_rdatatype_tsig && rdtype != dns_rdatatype_opt - && rdtype != dns_rdatatype_dnskey /* in a TKEY query */ + && rdtype != dns_rdatatype_key /* in a TKEY query */ && rdtype != dns_rdatatype_sig /* SIG(0) */ && rdtype != dns_rdatatype_tkey /* Win2000 TKEY */ && msg->rdclass != dns_rdataclass_any && msg->rdclass != rdclass) DO_FORMERR; + /* + * If this is not a TKEY query/response then the KEY + * record's class needs to match. + */ + if (msg->opcode != dns_opcode_update && !msg->tkey && + rdtype == dns_rdatatype_key && + msg->rdclass != dns_rdataclass_any && + msg->rdclass != rdclass) + DO_FORMERR; + /* * Special type handling for TSIG, OPT, and TKEY. */ @@ -1375,6 +1393,10 @@ getsection(isc_buffer_t *source, dns_message_t *msg, dns_decompress_t *dctx, skip_name_search = ISC_TRUE; skip_type_search = ISC_TRUE; issigzero = ISC_TRUE; + } else { + if (msg->rdclass != dns_rdataclass_any && + msg->rdclass != rdclass) + DO_FORMERR; } } else covers = 0; @@ -1619,6 +1641,7 @@ dns_message_parse(dns_message_t *msg, isc_buffer_t *source, msg->counts[DNS_SECTION_ADDITIONAL] = isc_buffer_getuint16(source); msg->header_ok = 1; + msg->state = DNS_SECTION_QUESTION; /* * -1 means no EDNS. @@ -3608,3 +3631,15 @@ dns_message_buildopt(dns_message_t *message, dns_rdataset_t **rdatasetp, dns_message_puttemprdatalist(message, &rdatalist); return (result); } + +void +dns_message_setclass(dns_message_t *msg, dns_rdataclass_t rdclass) { + + REQUIRE(DNS_MESSAGE_VALID(msg)); + REQUIRE(msg->from_to_wire == DNS_MESSAGE_INTENTPARSE); + REQUIRE(msg->state == DNS_SECTION_ANY); + REQUIRE(msg->rdclass_set == 0); + + msg->rdclass = rdclass; + msg->rdclass_set = 1; +} diff --git a/lib/dns/resolver.c b/lib/dns/resolver.c index 749264bc75..f93b92c0cc 100644 --- a/lib/dns/resolver.c +++ b/lib/dns/resolver.c @@ -7403,8 +7403,11 @@ resquery_response(isc_task_t *task, isc_event_t *event) { } } + dns_message_setclass(message, res->rdclass); + if ((options & DNS_FETCHOPT_TCP) == 0) dns_adb_plainresponse(fctx->adb, query->addrinfo); + result = dns_message_parse(message, &devent->buffer, 0); if (result != ISC_R_SUCCESS) { FCTXTRACE3("message failed to parse", result); @@ -7477,6 +7480,12 @@ resquery_response(isc_task_t *task, isc_event_t *event) { */ log_packet(message, ISC_LOG_DEBUG(10), res->mctx); + if (message->rdclass != res->rdclass) { + resend = ISC_TRUE; + FCTXTRACE("bad class"); + goto done; + } + /* * Process receive opt record. */ diff --git a/lib/dns/xfrin.c b/lib/dns/xfrin.c index c841d8909e..aec238d3fc 100644 --- a/lib/dns/xfrin.c +++ b/lib/dns/xfrin.c @@ -1221,6 +1221,8 @@ xfrin_recv_done(isc_task_t *task, isc_event_t *ev) { msg->tsigctx = xfr->tsigctx; xfr->tsigctx = NULL; + dns_message_setclass(msg, xfr->rdclass); + if (xfr->nmsg > 0) msg->tcp_continuation = 1;