--- bind-9.3.2/lib/dns/resolver.c.cve-2007-0493-0494 2007-01-29 13:35:48.000000000 -0700
+++ bind-9.3.2/lib/dns/resolver.c 2007-01-29 13:50:07.000000000 -0700
@@ -215,6 +215,11 @@
dns_name_t nsname;
dns_fetch_t * nsfetch;
dns_rdataset_t nsrrset;
+
+ /*%
+ * Number of queries that reference this context.
+ */
+ unsigned int nqueries;
};
#define FCTX_MAGIC ISC_MAGIC('F', '!', '!', '!')
@@ -348,6 +353,7 @@
dns_rdataset_t *ardataset,
isc_result_t *eresultp);
static void validated(isc_task_t *task, isc_event_t *event);
+static void maybe_destroy(fetchctx_t *fctx);
static isc_result_t
valcreate(fetchctx_t *fctx, dns_adbaddrinfo_t *addrinfo, dns_name_t *name,
@@ -366,6 +372,9 @@
valarg->fctx = fctx;
valarg->addrinfo = addrinfo;
+ if (!ISC_LIST_EMPTY(fctx->validators))
+ INSIST((valoptions & DNS_VALIDATOR_DEFER) != 0);
+
result = dns_validator_create(fctx->res->view, name, type, rdataset,
sigrdataset, fctx->rmessage,
valoptions, task, validated, valarg,
@@ -513,6 +522,9 @@
INSIST(query->tcpsocket == NULL);
+ query->fctx->nqueries--;
+ if (SHUTTINGDOWN(query->fctx))
+ maybe_destroy(query->fctx); /* Locks bucket. */
query->magic = 0;
isc_mem_put(query->mctx, query, sizeof(*query));
*queryp = NULL;
@@ -971,6 +983,8 @@
if (result != ISC_R_SUCCESS)
return (result);
+ INSIST(ISC_LIST_EMPTY(fctx->validators));
+
dns_message_reset(fctx->rmessage, DNS_MESSAGE_INTENTPARSE);
query = isc_mem_get(res->mctx, sizeof(*query));
@@ -1084,6 +1098,7 @@
}
ISC_LIST_APPEND(fctx->queries, query, link);
+ query->fctx->nqueries++;
return (ISC_R_SUCCESS);
@@ -1530,7 +1545,7 @@
want_done = ISC_TRUE;
}
} else if (SHUTTINGDOWN(fctx) && fctx->pending == 0 &&
- ISC_LIST_EMPTY(fctx->validators)) {
+ fctx->nqueries == 0 && ISC_LIST_EMPTY(fctx->validators)) {
bucketnum = fctx->bucketnum;
LOCK(&res->buckets[bucketnum].lock);
/*
@@ -2384,8 +2399,8 @@
REQUIRE(ISC_LIST_EMPTY(fctx->finds));
REQUIRE(ISC_LIST_EMPTY(fctx->altfinds));
REQUIRE(fctx->pending == 0);
- REQUIRE(ISC_LIST_EMPTY(fctx->validators));
REQUIRE(fctx->references == 0);
+ REQUIRE(ISC_LIST_EMPTY(fctx->validators));
FCTXTRACE("destroy");
@@ -2559,7 +2574,7 @@
}
if (fctx->references == 0 && fctx->pending == 0 &&
- ISC_LIST_EMPTY(fctx->validators))
+ fctx->nqueries == 0 && ISC_LIST_EMPTY(fctx->validators))
bucket_empty = fctx_destroy(fctx);
UNLOCK(&res->buckets[bucketnum].lock);
@@ -2600,6 +2615,7 @@
* pending ADB finds and no pending validations.
*/
INSIST(fctx->pending == 0);
+ INSIST(fctx->nqueries == 0);
INSIST(ISC_LIST_EMPTY(fctx->validators));
if (fctx->references == 0) {
/*
@@ -2761,6 +2777,7 @@
fctx->restarts = 0;
fctx->timeouts = 0;
fctx->attributes = 0;
+ fctx->nqueries = 0;
dns_name_init(&fctx->nsname, NULL);
fctx->nsfetch = NULL;
@@ -3083,12 +3100,21 @@
unsigned int bucketnum;
isc_boolean_t bucket_empty = ISC_FALSE;
dns_resolver_t *res = fctx->res;
+ dns_validator_t *validator;
REQUIRE(SHUTTINGDOWN(fctx));
- if (fctx->pending != 0 || !ISC_LIST_EMPTY(fctx->validators))
+ if (fctx->pending != 0 || fctx->nqueries != 0)
return;
+ for (validator = ISC_LIST_HEAD(fctx->validators);
+ validator != NULL;
+ validator = ISC_LIST_HEAD(fctx->validators)) {
+ ISC_LIST_UNLINK(fctx->validators, validator, link);
+ dns_validator_cancel(validator);
+ dns_validator_destroy(&validator);
+ }
+
bucketnum = fctx->bucketnum;
LOCK(&res->buckets[bucketnum].lock);
if (fctx->references == 0)
@@ -3219,7 +3245,9 @@
result = vevent->result;
add_bad(fctx, &addrinfo->sockaddr, result);
isc_event_free(&event);
- if (sentresponse)
+ if (!ISC_LIST_EMPTY(fctx->validators))
+ dns_validator_send(ISC_LIST_HEAD(fctx->validators));
+ else if (sentresponse)
fctx_done(fctx, result);
else
fctx_try(fctx);
@@ -3315,6 +3343,7 @@
* more rdatasets that still need to
* be validated.
*/
+ dns_validator_send(ISC_LIST_HEAD(fctx->validators));
goto cleanup_event;
}
@@ -3623,6 +3652,13 @@
rdataset,
sigrdataset,
valoptions, task);
+ /*
+ * Defer any further validations.
+ * This prevents multiple validators
+ * from manipulating fctx->rmessage
+ * simultaniously.
+ */
+ valoptions |= DNS_VALIDATOR_DEFER;
}
} else if (CHAINING(rdataset)) {
if (rdataset->type == dns_rdatatype_cname)
@@ -6346,7 +6382,8 @@
/*
* No one cares about the result of this fetch anymore.
*/
- if (fctx->pending == 0 && ISC_LIST_EMPTY(fctx->validators) &&
+ if (fctx->pending == 0 && fctx->nqueries == 0 &&
+ ISC_LIST_EMPTY(fctx->validators) &&
SHUTTINGDOWN(fctx)) {
/*
* This fctx is already shutdown; we were just
--- bind-9.3.2/lib/dns/validator.c.cve-2007-0493-0494 2007-01-29 13:35:48.000000000 -0700
+++ bind-9.3.2/lib/dns/validator.c 2007-01-29 13:38:03.000000000 -0700
@@ -2632,7 +2632,8 @@
ISC_LINK_INIT(val, link);
val->magic = VALIDATOR_MAGIC;
- isc_task_send(task, ISC_EVENT_PTR(&event));
+ if ((options & DNS_VALIDATOR_DEFER) == 0)
+ isc_task_send(task, ISC_EVENT_PTR(&event));
*validatorp = val;
@@ -2650,6 +2651,21 @@
}
void
+dns_validator_send(dns_validator_t *validator) {
+ isc_event_t *event;
+ REQUIRE(VALID_VALIDATOR(validator));
+
+ LOCK(&validator->lock);
+
+ INSIST((validator->options & DNS_VALIDATOR_DEFER) != 0);
+ event = (isc_event_t *)validator->event;
+ validator->options &= ~DNS_VALIDATOR_DEFER;
+ UNLOCK(&validator->lock);
+
+ isc_task_send(validator->task, ISC_EVENT_PTR(&event));
+}
+
+void
dns_validator_cancel(dns_validator_t *validator) {
REQUIRE(VALID_VALIDATOR(validator));
@@ -2663,6 +2679,12 @@
if (validator->subvalidator != NULL)
dns_validator_cancel(validator->subvalidator);
+ if ((validator->options & DNS_VALIDATOR_DEFER) != 0) {
+ isc_task_t *task = validator->event->ev_sender;
+ validator->options &= ~DNS_VALIDATOR_DEFER;
+ isc_event_free((isc_event_t **)&validator->event);
+ isc_task_detach(&task);
+ }
}
UNLOCK(&validator->lock);
}
--- bind-9.3.2/lib/dns/include/dns/validator.h.cve-2007-0493-0494 2007-01-29 13:35:48.000000000 -0700
+++ bind-9.3.2/lib/dns/include/dns/validator.h 2007-01-29 13:41:06.000000000 -0700
@@ -128,7 +128,11 @@
unsigned int depth;
};
+/*
+ * dns_validator_create() options.
+ */
#define DNS_VALIDATOR_DLV 1
+#define DNS_VALIDATOR_DEFER 2U
ISC_LANG_BEGINDECLS
@@ -173,6 +177,15 @@
*/
void
+dns_validator_send(dns_validator_t *validator);
+/*%<
+ * Send a deferred validation request
+ *
+ * Requires:
+ * 'validator' to points to a valid DNSSEC validator.
+ */
+
+void
dns_validator_cancel(dns_validator_t *validator);
/*
* Cancel a DNSSEC validation in progress.
