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Viewing changes to lib/dns/resolver.c

  • Committer: Bazaar Package Importer
  • Author(s): Marc Deslauriers
  • Date: 2011-07-05 08:33:30 UTC
  • Revision ID: james.westby@ubuntu.com-20110705083330-yy2urqvf4cooh9wm
Tags: 1:9.7.3.dfsg-1ubuntu3
* SECURITY UPDATE: denial of service via specially crafted packet
  - lib/dns/include/dns/rdataset.h, lib/dns/{masterdump,message,ncache,
    nsec3,rbtdb,rdataset,resolver,validator}.c: Use an rdataset attribute
    flag to indicate negative-cache records rather than using rrtype 0.
  - Patch backported from 9.7.3-P3.
  - CVE-2011-2464

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Lines of Context:
lib/dns/resolver.c
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                                         FCTX_ADDRINFO_TRIED) != 0)
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#define NXDOMAIN(r) (((r)->attributes & DNS_RDATASETATTR_NXDOMAIN) != 0)
 
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#define NEGATIVE(r) (((r)->attributes & DNS_RDATASETATTR_NEGATIVE) != 0)
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static void destroy(dns_resolver_t *res);
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static void empty_bucket(dns_resolver_t *res);
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                 * Negative results must be indicated in event->result.
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                 */
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                if (dns_rdataset_isassociated(event->rdataset) &&
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                    event->rdataset->type == dns_rdatatype_none) {
 
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                    NEGATIVE(event->rdataset)) {
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                        INSIST(event->result == DNS_R_NCACHENXDOMAIN ||
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                               event->result == DNS_R_NCACHENXRRSET);
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                }
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        if (result != ISC_R_SUCCESS &&
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            result != DNS_R_UNCHANGED)
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                goto noanswer_response;
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        if (ardataset != NULL && ardataset->type == 0) {
 
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        if (ardataset != NULL && NEGATIVE(ardataset)) {
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                if (NXDOMAIN(ardataset))
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                        eresult = DNS_R_NCACHENXDOMAIN;
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                else
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                                        result = ISC_R_SUCCESS;
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                                        if (!need_validation &&
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                                            ardataset != NULL &&
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                                            ardataset->type == 0) {
 
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                                            NEGATIVE(ardataset)) {
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                                                /*
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                                                 * The answer in the cache is
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                                                 * better than the answer we
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                        if (result == DNS_R_UNCHANGED) {
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                                if (ANSWER(rdataset) &&
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                                    ardataset != NULL &&
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                                    ardataset->type == 0) {
 
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                                    NEGATIVE(ardataset)) {
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                                        /*
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                                         * The answer in the cache is better
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                                         * than the answer we found, and is
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                         * Negative results must be indicated in event->result.
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                         */
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                        if (dns_rdataset_isassociated(event->rdataset) &&
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                            event->rdataset->type == dns_rdatatype_none) {
 
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                            NEGATIVE(event->rdataset)) {
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                                INSIST(eresult == DNS_R_NCACHENXDOMAIN ||
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                                       eresult == DNS_R_NCACHENXRRSET);
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                        }
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                 * care about whether it is DNS_R_NCACHENXDOMAIN or
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                 * DNS_R_NCACHENXRRSET then extract it.
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                 */
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                if (ardataset->type == 0) {
 
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                if (NEGATIVE(ardataset)) {
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                        /*
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                         * The cache data is a negative cache entry.
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                         */