From c987bcb87aef1d85ededa7bc763ad895dcc57e70 Mon Sep 17 00:00:00 2001 From: delphij Date: Wed, 16 Dec 2015 06:21:26 +0000 Subject: [PATCH] Fix BIND remote denial of service vulnerability. [SA-15:27] Security: FreeBSD-SA-15:27.bind Security: CVE-2015-8000 Approved by: so git-svn-id: svn://svn.freebsd.org/base/releng/9.3@292321 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f --- UPDATING | 3 ++ contrib/bind9/lib/dns/include/dns/message.h | 13 +++++- contrib/bind9/lib/dns/message.c | 45 ++++++++++++++++++--- contrib/bind9/lib/dns/resolver.c | 8 ++++ contrib/bind9/lib/dns/xfrin.c | 2 + sys/conf/newvers.sh | 2 +- 6 files changed, 65 insertions(+), 8 deletions(-) diff --git a/UPDATING b/UPDATING index 2d16a49dc..0242cb81f 100644 --- a/UPDATING +++ b/UPDATING @@ -11,6 +11,9 @@ handbook: Items affecting the ports and packages system can be found in /usr/ports/UPDATING. Please read that file before running portupgrade. +20151216 p32 FreeBSD-SA-15:27.bind + Fix BIND remote denial of service vulnerability. [SA-15:27] + 20151205 p31 FreeBSD-SA-15:26.openssl Fix OpenSSL X509_ATTRIBUTE memory leak. [SA-15:26] diff --git a/contrib/bind9/lib/dns/include/dns/message.h b/contrib/bind9/lib/dns/include/dns/message.h index 6b2f39fc9..a4ef9689b 100644 --- a/contrib/bind9/lib/dns/include/dns/message.h +++ b/contrib/bind9/lib/dns/include/dns/message.h @@ -15,8 +15,6 @@ * PERFORMANCE OF THIS SOFTWARE. */ -/* $Id$ */ - #ifndef DNS_MESSAGE_H #define DNS_MESSAGE_H 1 @@ -211,6 +209,8 @@ 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; @@ -1375,6 +1375,15 @@ 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/contrib/bind9/lib/dns/message.c b/contrib/bind9/lib/dns/message.c index 901c6b6d9..de1967b2a 100644 --- a/contrib/bind9/lib/dns/message.c +++ b/contrib/bind9/lib/dns/message.c @@ -436,6 +436,8 @@ 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; } @@ -1086,12 +1088,18 @@ 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. */ @@ -1236,12 +1244,12 @@ 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; } /* @@ -1251,13 +1259,23 @@ 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. */ @@ -1372,6 +1390,10 @@ 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; @@ -1610,6 +1632,7 @@ 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. @@ -3550,3 +3573,15 @@ 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/contrib/bind9/lib/dns/resolver.c b/contrib/bind9/lib/dns/resolver.c index 85d3cb941..1723d49da 100644 --- a/contrib/bind9/lib/dns/resolver.c +++ b/contrib/bind9/lib/dns/resolver.c @@ -6941,6 +6941,8 @@ resquery_response(isc_task_t *task, isc_event_t *event) { goto done; } + dns_message_setclass(message, fctx->res->rdclass); + result = dns_message_parse(message, &devent->buffer, 0); if (result != ISC_R_SUCCESS) { switch (result) { @@ -7013,6 +7015,12 @@ resquery_response(isc_task_t *task, isc_event_t *event) { */ log_packet(message, ISC_LOG_DEBUG(10), fctx->res->mctx); + if (message->rdclass != fctx->res->rdclass) { + resend = ISC_TRUE; + FCTXTRACE("bad class"); + goto done; + } + /* * Process receive opt record. */ diff --git a/contrib/bind9/lib/dns/xfrin.c b/contrib/bind9/lib/dns/xfrin.c index 30f2f3b34..d8f8ced66 100644 --- a/contrib/bind9/lib/dns/xfrin.c +++ b/contrib/bind9/lib/dns/xfrin.c @@ -1211,6 +1211,8 @@ 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; diff --git a/sys/conf/newvers.sh b/sys/conf/newvers.sh index 7152c11ca..7659d2a44 100644 --- a/sys/conf/newvers.sh +++ b/sys/conf/newvers.sh @@ -32,7 +32,7 @@ TYPE="FreeBSD" REVISION="9.3" -BRANCH="RELEASE-p31" +BRANCH="RELEASE-p32" if [ "X${BRANCH_OVERRIDE}" != "X" ]; then BRANCH=${BRANCH_OVERRIDE} fi -- 2.42.0