506137 ns-slapd hang while group aci performance testing

Bug description: If a group has more than 32767 members (max short),
a variable 'n' declared as short overflows.  The value is used to calculate an
array size to store group member info, which memory is not properly allocated
and it ends up crashing up the server.

Fix description: Replaced the problematic short variable type with integer.
Plus, the each member info was storing a pointer pointing to an element inside
of the array.  When the array is "realloc"ed, it's possible for the addresses
to be relocated.  To solve the problem, the new code stores the index of array
instead of the address.

ldap/servers/plugins/acl/acllas.c

@@ -1149,7 +1149,7 @@ DS_LASUserDnAttrEval(NSErr_t *errp, char *attr_name, CmpOp_t comparator,
 	Slapi_Attr 		*a;
 	int				levels[ACLLAS_MAX_LEVELS];
 	int				numOflevels =0;
-	struct userdnattr_info	info;
+	struct userdnattr_info	info = {0};
 	char			*attrs[2] = { LDAP_ALL_USER_ATTRS, NULL };
 	lasInfo			lasinfo;
 	int				got_undefined = 0;
@@ -1399,7 +1399,7 @@ DS_LASLdapUrlAttrEval(NSErr_t *errp, char *attr_name, CmpOp_t comparator,
 	int				rc, len, i;
 	int				levels[ACLLAS_MAX_LEVELS];
 	int				numOflevels =0;
-	struct userdnattr_info	info;
+	struct userdnattr_info	info = {0};
 	char			*attrs[2] = { LDAP_ALL_USER_ATTRS, NULL };
 	int				got_undefined = 0;
 
@@ -1698,8 +1698,8 @@ DS_LASAuthMethodEval(NSErr_t *errp, char *attr_name, CmpOp_t comparator,
 struct member_info 
 {
 	char			*member;		/* member DN */
-	struct member_info	*parent;		/* parent of this member */
-} member_info;
+	int				parentId;		/* parent of this member */
+};
 
 struct eval_info
 {
@@ -1711,16 +1711,17 @@ struct eval_info
 	struct member_info 	**memberInfo;/* array of memberInfo  */
 	CERTCertificate		*clientCert;	/* ptr to cert */
 	struct acl_pblock 	*aclpb;	/*aclpblock */
-} eval_info;
+};
 
+#ifdef FOR_DEBUGGING
 static void
-dump_member_info ( struct member_info *minfo, char *buf )
+dump_member_info ( struct eval_info *info, struct member_info *minfo, char *buf )
 {
 	if ( minfo )
 	{
-		if ( minfo->parent )
+		if ( minfo->parentId >= 0 )
 		{
-			dump_member_info ( minfo->parent, buf );
+			dump_member_info ( info, minfo->parentId, buf );
 		}
 		else
 		{
@@ -1731,7 +1732,6 @@ dump_member_info ( struct member_info *minfo, char *buf )
 	}
 }
 
-#ifdef FOR_DEBUGGING
 static void
 dump_eval_info (char *caller, struct eval_info *info, int idx)
 {
@@ -1755,7 +1755,7 @@ dump_eval_info (char *caller, struct eval_info *info, int idx)
 		{
 			len = strlen(buf);
 			sprintf ( &buf[len], "\n  [%d]: ", i );
-			dump_member_info ( info->memberInfo[i], buf );
+			dump_member_info ( info, info->memberInfo[i], buf );
 		}
 		slapi_log_error ( SLAPI_LOG_FATAL, NULL, "\n======== candidate member info in eval_info ========%s\n\n", buf );
 	}
@@ -1778,7 +1778,7 @@ dump_eval_info (char *caller, struct eval_info *info, int idx)
 				sprintf ( &(buf[len]), "%d\n", info->result );
 				break;
 		}
-		dump_member_info ( info->memberInfo[idx], buf );
+		dump_member_info ( info, info->memberInfo[idx], buf );
 		slapi_log_error ( SLAPI_LOG_FATAL, NULL, "%s\n", buf );
 	}
 }
@@ -1817,7 +1817,7 @@ acllas__user_ismember_of_group( struct acl_pblock *aclpb,
 	char			*currDN;
 	int			i,j;
 	int			result = ACL_FALSE;
-	struct eval_info	info;
+	struct eval_info	info = {0};
 	int			nesting_level;
 	int 			numOfMembersAtCurrentLevel;
 	int			numOfMembersVisited;
@@ -1885,7 +1885,7 @@ acllas__user_ismember_of_group( struct acl_pblock *aclpb,
 	info.memberInfo = (struct member_info **) slapi_ch_malloc (ACLLAS_MAX_GRP_MEMBER * sizeof(struct member_info *));
 	groupMember = (struct member_info *) slapi_ch_malloc ( sizeof (struct member_info) );
 	groupMember->member = slapi_ch_strdup(groupDN);
-	groupMember->parent = NULL;
+	groupMember->parentId = -1;
 	info.memberInfo[0] = groupMember;
 	info.lu_idx = 0;
 
@@ -2092,7 +2092,7 @@ free_and_return:
 		while ( groupMember ) {
 			int already_cached = 0;
 
-			parentGroup = groupMember->parent;
+			parentGroup = (groupMember->parentId<0)?NULL:info.memberInfo[groupMember->parentId];
 			for (j=0; j < u_group->aclug_numof_member_group;j++){
 				if (slapi_utf8casecmp( (ACLUCHP)groupMember->member,
                                  (ACLUCHP)u_group->aclug_member_groups[j]) == 0) {
@@ -2137,7 +2137,7 @@ free_and_return:
 		while ( groupMember ) {
 			int already_cached = 0;
 
-			parentGroup = groupMember->parent;
+			parentGroup = (groupMember->parentId<0)?NULL:info.memberInfo[groupMember->parentId];
 			for (j=0; j < u_group->aclug_numof_notmember_group;j++){
 				if (slapi_utf8casecmp( (ACLUCHP)groupMember->member,
                                	(ACLUCHP)u_group->aclug_notmember_groups[j]) == 0) {
@@ -2217,8 +2217,8 @@ acllas__handle_group_entry (Slapi_Entry* e, void *callback_data)
 	struct eval_info	*info;
  	Slapi_Attr		*currAttr, *nextAttr;
 	char			*n_dn, *attrType;
-	short			n;
-	int i;
+	int				n;
+	int				i, j;
 
 	info = (struct eval_info *) callback_data;
 	info->result = ACL_FALSE;
@@ -2234,7 +2234,7 @@ acllas__handle_group_entry (Slapi_Entry* e, void *callback_data)
 	if (NULL == attrType ) return 0;
 
 	do {
-		Slapi_Value *sval=NULL;
+		Slapi_Value *sval = NULL;
 		const struct berval		*attrVal;
 
  		if ((strcasecmp (attrType, type_member) == 0) ||
@@ -2244,20 +2244,26 @@ acllas__handle_group_entry (Slapi_Entry* e, void *callback_data)
 			while ( i != -1 ) {
 				struct member_info	*groupMember = NULL;
 				attrVal = slapi_value_get_berval ( sval );
-				n_dn = slapi_dn_normalize ( slapi_ch_strdup( attrVal->bv_val));
-				info->lu_idx++;
-				n = info->lu_idx;
+				n_dn = slapi_dn_normalize ( slapi_ch_strdup( attrVal->bv_val ));
+				n = ++info->lu_idx;
+				if (n < 0) {
+					slapi_log_error( SLAPI_LOG_FATAL, plugin_name,
+						  "acllas__handle_group_entry: last member index lu_idx is overflown:%d: Too many group ACL members\n", n);
+					return 0;
+				}
 				if (!(n % ACLLAS_MAX_GRP_MEMBER)) {
-					info->memberInfo = (struct member_info **) slapi_ch_realloc( 
-							(void *) info->memberInfo,
-					      		(n+ACLLAS_MAX_GRP_MEMBER) * 
-							sizeof(struct eval_info *));
+					struct member_info *orig_memberInfo = info->memberInfo[0];
+					info->memberInfo = (struct member_info **)slapi_ch_realloc(
+							(char *)info->memberInfo,
+							(n + ACLLAS_MAX_GRP_MEMBER) *
+							sizeof(struct member_info *));
 				}
 
 				/* allocate the space for the member and attch it to the list */
-				groupMember = (struct member_info *) slapi_ch_malloc ( sizeof ( struct member_info ) );
+				groupMember = (struct member_info *)slapi_ch_malloc(
+								sizeof ( struct member_info ) );
 				groupMember->member = n_dn;
-				groupMember->parent = info->memberInfo[info->c_idx];
+				groupMember->parentId = info->c_idx;
 				info->memberInfo[n] = groupMember;
 
 				if (info->userDN && 
@@ -2702,7 +2708,7 @@ acllas__eval_memberGroupDnAttr (char *attrName, Slapi_Entry *e,
 	if (enumerate_groups) {
 		char			filter_str[BUFSIZ];
 		char			*attrs[3];
-		struct eval_info	info;
+		struct eval_info	info = {0};
 		char			*curMemberDn;
 		int			Done = 0;
 		int			ngr, tt;
@@ -2892,7 +2898,7 @@ acllas__add_allgroups (Slapi_Entry* e, void *callback_data)
 	}
 
 	m = info->lu_idx;
-	n = info->lu_idx++;
+	n = ++info->lu_idx;
 	if (!(n % ACLLAS_MAX_GRP_MEMBER)) {
 		info->member = (char **) slapi_ch_realloc (
 					(void *) info->member,