libnet_join_set_machine_spn: simplify memory handling

and avoid a possible memory leak when passing null to
add_string_to_array() as mem_ctx.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=14116

Signed-off-by: Isaac Boukris <iboukris@redhat.com>
Reviewed-by: Ralph Boehme <slow@samba.org>
Reviewed-by: Alexander Bokovoy <ab@samba.org>

diff --git a/source3/libnet/libnet_join.c b/source3/libnet/libnet_join.c
index 67ab50c68a8d78f7d68833de074db53c3befcd1a..430353705267bc7cd6a81855e687cb2d26b0ec18 100644 (file)
--- a/source3/libnet/libnet_join.c
+++ b/source3/libnet/libnet_join.c
@@ -490,6 +490,7 @@ static ADS_STATUS libnet_join_get_machine_spns(TALLOC_CTX *mem_ctx,
 static ADS_STATUS libnet_join_set_machine_spn(TALLOC_CTX *mem_ctx,
                                              struct libnet_JoinCtx *r)
 {
+       TALLOC_CTX *frame = talloc_stackframe();
        ADS_STATUS status;
        ADS_MODLIST mods;
        fstring my_fqdn;
@@ -506,7 +507,7 @@ static ADS_STATUS libnet_join_set_machine_spn(TALLOC_CTX *mem_ctx,
                return status;
        }
 
-       status = libnet_join_get_machine_spns(mem_ctx,
+       status = libnet_join_get_machine_spns(frame,
                                              r,
                                              discard_const_p(char **, &spn_array),
                                              &num_spns);
@@ -516,40 +517,46 @@ static ADS_STATUS libnet_join_set_machine_spn(TALLOC_CTX *mem_ctx,
 
        /* Windows only creates HOST/shortname & HOST/fqdn. */
 
-       spn = talloc_asprintf(mem_ctx, "HOST/%s", r->in.machine_name);
+       spn = talloc_asprintf(frame, "HOST/%s", r->in.machine_name);
        if (spn == NULL) {
-               return ADS_ERROR_LDAP(LDAP_NO_MEMORY);
+               status = ADS_ERROR_LDAP(LDAP_NO_MEMORY);
+               goto done;
        }
        if (!strupper_m(spn)) {
-               return ADS_ERROR_LDAP(LDAP_NO_MEMORY);
+               status = ADS_ERROR_LDAP(LDAP_NO_MEMORY);
+               goto done;
        }
 
        ok = ads_element_in_array(spn_array, num_spns, spn);
        if (!ok) {
-               ok = add_string_to_array(spn_array, spn,
+               ok = add_string_to_array(frame, spn,
                                         &spn_array, &num_spns);
                if (!ok) {
-                       return ADS_ERROR_LDAP(LDAP_NO_MEMORY);
+                       status = ADS_ERROR_LDAP(LDAP_NO_MEMORY);
+                       goto done;
                }
        }
 
        fstr_sprintf(my_fqdn, "%s.%s", r->in.machine_name, lp_dnsdomain());
 
        if (!strlower_m(my_fqdn)) {
-               return ADS_ERROR_LDAP(LDAP_NO_MEMORY);
+               status = ADS_ERROR_LDAP(LDAP_NO_MEMORY);
+               goto done;
        }
 
-       spn = talloc_asprintf(mem_ctx, "HOST/%s", my_fqdn);
+       spn = talloc_asprintf(frame, "HOST/%s", my_fqdn);
        if (spn == NULL) {
-               return ADS_ERROR_LDAP(LDAP_NO_MEMORY);
+               status = ADS_ERROR_LDAP(LDAP_NO_MEMORY);
+               goto done;
        }
 
        ok = ads_element_in_array(spn_array, num_spns, spn);
        if (!ok) {
-               ok = add_string_to_array(spn_array, spn,
+               ok = add_string_to_array(frame, spn,
                                         &spn_array, &num_spns);
                if (!ok) {
-                       return ADS_ERROR_LDAP(LDAP_NO_MEMORY);
+                       status = ADS_ERROR_LDAP(LDAP_NO_MEMORY);
+                       goto done;
                }
        }
 
@@ -559,28 +566,26 @@ static ADS_STATUS libnet_join_set_machine_spn(TALLOC_CTX *mem_ctx,
                /*
                 * Add HOST/NETBIOSNAME
                 */
-               spn = talloc_asprintf(mem_ctx, "HOST/%s", *netbios_aliases);
+               spn = talloc_asprintf(frame, "HOST/%s", *netbios_aliases);
                if (spn == NULL) {
-                       TALLOC_FREE(spn);
-                       return ADS_ERROR_LDAP(LDAP_NO_MEMORY);
+                       status = ADS_ERROR_LDAP(LDAP_NO_MEMORY);
+                       goto done;
                }
                if (!strupper_m(spn)) {
-                       TALLOC_FREE(spn);
-                       return ADS_ERROR_LDAP(LDAP_NO_MEMORY);
+                       status = ADS_ERROR_LDAP(LDAP_NO_MEMORY);
+                       goto done;
                }
 
                ok = ads_element_in_array(spn_array, num_spns, spn);
                if (ok) {
-                       TALLOC_FREE(spn);
                        continue;
                }
                ok = add_string_to_array(spn_array, spn,
                                         &spn_array, &num_spns);
                if (!ok) {
-                       TALLOC_FREE(spn);
-                       return ADS_ERROR_LDAP(LDAP_NO_MEMORY);
+                       status = ADS_ERROR_LDAP(LDAP_NO_MEMORY);
+                       goto done;
                }
-               TALLOC_FREE(spn);
 
                /*
                 * Add HOST/netbiosname.domainname
@@ -589,51 +594,56 @@ static ADS_STATUS libnet_join_set_machine_spn(TALLOC_CTX *mem_ctx,
                             *netbios_aliases,
                             lp_dnsdomain());
 
-               spn = talloc_asprintf(mem_ctx, "HOST/%s", my_fqdn);
+               spn = talloc_asprintf(frame, "HOST/%s", my_fqdn);
                if (spn == NULL) {
-                       return ADS_ERROR_LDAP(LDAP_NO_MEMORY);
+                       status = ADS_ERROR_LDAP(LDAP_NO_MEMORY);
+                       goto done;
                }
 
                ok = ads_element_in_array(spn_array, num_spns, spn);
                if (ok) {
-                       TALLOC_FREE(spn);
                        continue;
                }
                ok = add_string_to_array(spn_array, spn,
                                         &spn_array, &num_spns);
                if (!ok) {
-                       TALLOC_FREE(spn);
-                       return ADS_ERROR_LDAP(LDAP_NO_MEMORY);
+                       status = ADS_ERROR_LDAP(LDAP_NO_MEMORY);
+                       goto done;
                }
-               TALLOC_FREE(spn);
        }
 
        /* make sure to NULL terminate the array */
-       spn_array = talloc_realloc(mem_ctx, spn_array, const char *, num_spns + 1);
+       spn_array = talloc_realloc(frame, spn_array, const char *, num_spns + 1);
        if (spn_array == NULL) {
-               return ADS_ERROR_LDAP(LDAP_NO_MEMORY);
+               status = ADS_ERROR_LDAP(LDAP_NO_MEMORY);
+               goto done;
        }
        spn_array[num_spns] = NULL;
 
        mods = ads_init_mods(mem_ctx);
        if (!mods) {
-               return ADS_ERROR_LDAP(LDAP_NO_MEMORY);
+               status = ADS_ERROR_LDAP(LDAP_NO_MEMORY);
+               goto done;
        }
 
        /* fields of primary importance */
 
        status = ads_mod_str(mem_ctx, &mods, "dNSHostName", my_fqdn);
        if (!ADS_ERR_OK(status)) {
-               return ADS_ERROR_LDAP(LDAP_NO_MEMORY);
+               goto done;
        }
 
        status = ads_mod_strlist(mem_ctx, &mods, "servicePrincipalName",
                                 spn_array);
        if (!ADS_ERR_OK(status)) {
-               return ADS_ERROR_LDAP(LDAP_NO_MEMORY);
+               goto done;
        }
 
-       return ads_gen_mod(r->in.ads, r->out.dn, mods);
+       status = ads_gen_mod(r->in.ads, r->out.dn, mods);
+
+done:
+       TALLOC_FREE(frame);
+       return status;
 }
 
 /****************************************************************