From: Stefan Metzmacher <metze@samba.org>
Date: Tue, 22 Mar 2022 16:04:22 +0000 (+0100)
Subject: s4:kdc: let samba_kdc_entry take references to sdb_entry and kdc_entry
X-Git-Tag: tevent-0.12.0~324
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c2eb50861d52dbf32e021beb7a100f4446e1629b;p=thirdparty%2Fsamba.git

s4:kdc: let samba_kdc_entry take references to sdb_entry and kdc_entry

kdc_entry can be hdb_entry or krb5_db_entry.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
---

diff --git a/source4/kdc/db-glue.c b/source4/kdc/db-glue.c
index 3c9540eb348..592285511ce 100644
--- a/source4/kdc/db-glue.c
+++ b/source4/kdc/db-glue.c
@@ -252,6 +252,21 @@ static struct SDBFlags uf2SDBFlags(krb5_context context, uint32_t userAccountCon
 
 static int samba_kdc_entry_destructor(struct samba_kdc_entry *p)
 {
+	if (p->db_entry != NULL) {
+		/*
+		 * A sdb_entry still has a reference
+		 */
+		return -1;
+	}
+
+	if (p->kdc_entry != NULL) {
+		/*
+		 * hdb_entry or krb5_db_entry still
+		 * have a reference...
+		 */
+		return -1;
+	}
+
 	return 0;
 }
 
diff --git a/source4/kdc/hdb-samba4.c b/source4/kdc/hdb-samba4.c
index dcd9c3979aa..0c903afe35c 100644
--- a/source4/kdc/hdb-samba4.c
+++ b/source4/kdc/hdb-samba4.c
@@ -101,14 +101,17 @@ static void hdb_samba4_free_entry_context(krb5_context context, struct HDB *db,
 	 * 'context' set, so we have to check that the context is not NULL.
 	*/
 	if (entry->context != NULL) {
+		struct samba_kdc_entry *skdc_entry =
+			talloc_get_type_abort(entry->context,
+			struct samba_kdc_entry);
+
 		/* this function is called only from hdb_free_entry().
 		 * Make sure we neutralize the destructor or we will
 		 * get a double free later when hdb_free_entry() will
 		 * try to call free_hdb_entry() */
-		talloc_set_destructor(entry->context, NULL);
-
-		/* now proceed to free the talloc part */
-		talloc_free(entry->context);
+		entry->context = NULL;
+		skdc_entry->kdc_entry = NULL;
+		TALLOC_FREE(skdc_entry);
 	}
 }
 
diff --git a/source4/kdc/mit-kdb/kdb_samba.c b/source4/kdc/mit-kdb/kdb_samba.c
index 650df06882f..0ff1bfe6c5c 100644
--- a/source4/kdc/mit-kdb/kdb_samba.c
+++ b/source4/kdc/mit-kdb/kdb_samba.c
@@ -27,6 +27,7 @@
 #include <profile.h>
 #include <kdb.h>
 
+#include "kdc/samba_kdc.h"
 #include "kdc/mit_samba.h"
 #include "kdb_samba.h"
 
@@ -133,7 +134,7 @@ static void kdb_samba_db_free_principal_e_data(krb5_context context,
 
 	skdc_entry = talloc_get_type_abort(e_data,
 					   struct samba_kdc_entry);
-	talloc_set_destructor(skdc_entry, NULL);
+	skdc_entry->kdc_entry = NULL;
 	TALLOC_FREE(skdc_entry);
 }
 
diff --git a/source4/kdc/mit-kdb/kdb_samba_principals.c b/source4/kdc/mit-kdb/kdb_samba_principals.c
index 3917b9824c6..31983a7da6c 100644
--- a/source4/kdc/mit-kdb/kdb_samba_principals.c
+++ b/source4/kdc/mit-kdb/kdb_samba_principals.c
@@ -27,6 +27,7 @@
 #include <profile.h>
 #include <kdb.h>
 
+#include "kdc/samba_kdc.h"
 #include "kdc/mit_samba.h"
 #include "kdb_samba.h"
 
@@ -68,7 +69,7 @@ static void ks_free_principal_e_data(krb5_context context, krb5_octet *e_data)
 
 	skdc_entry = talloc_get_type_abort(e_data,
 					   struct samba_kdc_entry);
-	talloc_set_destructor(skdc_entry, NULL);
+	skdc_entry->kdc_entry = NULL;
 	TALLOC_FREE(skdc_entry);
 }
 
diff --git a/source4/kdc/samba_kdc.h b/source4/kdc/samba_kdc.h
index 4a0b4eff22e..2caefd58ae9 100644
--- a/source4/kdc/samba_kdc.h
+++ b/source4/kdc/samba_kdc.h
@@ -54,6 +54,8 @@ struct samba_kdc_db_context {
 
 struct samba_kdc_entry {
 	struct samba_kdc_db_context *kdc_db_ctx;
+	const struct sdb_entry *db_entry; /* this is only temporary valid */
+	const void *kdc_entry; /* this is a reference to hdb_entry/krb5_db_entry */
 	struct ldb_message *msg;
 	struct ldb_dn *realm_dn;
 	struct auth_user_info_dc *user_info_dc;
diff --git a/source4/kdc/sdb.c b/source4/kdc/sdb.c
index 3296e509e37..37784529f84 100644
--- a/source4/kdc/sdb.c
+++ b/source4/kdc/sdb.c
@@ -24,6 +24,7 @@
 #include "includes.h"
 #include "system/kerberos.h"
 #include "sdb.h"
+#include "samba_kdc.h"
 #include "lib/krb5_wrap/krb5_samba.h"
 
 static void free_sdb_entry(struct sdb_entry *s);
@@ -73,6 +74,11 @@ void sdb_keys_free(struct sdb_keys *keys)
 
 static void free_sdb_entry(struct sdb_entry *s)
 {
+	if (s->skdc_entry != NULL) {
+		s->skdc_entry->db_entry = NULL;
+		TALLOC_FREE(s->skdc_entry);
+	}
+
 	/*
 	 * Passing NULL as the Kerberos context is intentional here, as both
 	 * Heimdal and MIT libraries don't use the context when clearing the
diff --git a/source4/kdc/sdb_to_hdb.c b/source4/kdc/sdb_to_hdb.c
index 800dace005e..9cce5ead7ee 100644
--- a/source4/kdc/sdb_to_hdb.c
+++ b/source4/kdc/sdb_to_hdb.c
@@ -294,6 +294,9 @@ static int sdb_entry_to_hdb_entry(krb5_context context,
 	}
 
 	h->context = ske;
+	if (ske != NULL) {
+		ske->kdc_entry = h;
+	}
 	return 0;
 error:
 	free_hdb_entry(h);
diff --git a/source4/kdc/sdb_to_kdb.c b/source4/kdc/sdb_to_kdb.c
index a4a85537ac0..e617845ed78 100644
--- a/source4/kdc/sdb_to_kdb.c
+++ b/source4/kdc/sdb_to_kdb.c
@@ -311,6 +311,9 @@ static int sdb_entry_ex_to_krb5_db_entry(krb5_context context,
 	}
 
 	k->e_data = (void *)ske;
+	if (ske != NULL) {
+		ske->kdc_entry = k;
+	}
 	return 0;
 }