From c21e901ba735e927e345b65a35fcd6f585d0c2f3 Mon Sep 17 00:00:00 2001
From: "Christoph M. Becker" <cmbecker69@gmx.de>
Date: Thu, 29 Oct 2020 11:52:10 +0100
Subject: [PATCH] Fix #44618: Fetching may rely on uninitialized data

Unless `SQLGetData()` returns `SQL_SUCCESS` or `SQL_SUCCESS_WITH_INFO`,
the `StrLen_or_IndPtr` output argument is not guaranteed to be properly
set.  Thus we handle retrieval failure other than `SQL_ERROR` by
yielding `false` for those column values and raising a warning.

Closes GH-6281.
---
 NEWS                         |  3 ++
 ext/odbc/php_odbc.c          | 26 ++++++++++++---
 ext/odbc/tests/bug44618.phpt | 62 ++++++++++++++++++++++++++++++++++++
 3 files changed, 87 insertions(+), 4 deletions(-)
 create mode 100644 ext/odbc/tests/bug44618.phpt

diff --git a/NEWS b/NEWS
index 6d74ead2b9..72b47f2994 100644
--- a/NEWS
+++ b/NEWS
@@ -22,6 +22,9 @@ PHP                                                                        NEWS
   . Fixed bug #80242 (imap_mail_compose() segfaults for multipart with rfc822).
     (cmb)
 
+- ODBC:
+  . Fixed bug #44618 (Fetching may rely on uninitialized data). (cmb)
+
 29 Oct 2020, PHP 7.3.24
 
 - Core:
diff --git a/ext/odbc/php_odbc.c b/ext/odbc/php_odbc.c
index 1bb832553c..cc0580fb83 100644
--- a/ext/odbc/php_odbc.c
+++ b/ext/odbc/php_odbc.c
@@ -1810,6 +1810,9 @@ static void php_odbc_fetch_hash(INTERNAL_FUNCTION_PARAMETERS, int result_type)
 
 				if (rc == SQL_SUCCESS_WITH_INFO) {
 					ZVAL_STRINGL(&tmp, buf, result->longreadlen);
+				} else if (rc != SQL_SUCCESS) {
+					php_error_docref(NULL, E_WARNING, "Cannot get data of column #%d (retcode %u)", i + 1, rc);
+					ZVAL_FALSE(&tmp);
 				} else if (result->values[i].vallen == SQL_NULL_DATA) {
 					ZVAL_NULL(&tmp);
 					break;
@@ -1962,6 +1965,9 @@ PHP_FUNCTION(odbc_fetch_into)
 				}
 				if (rc == SQL_SUCCESS_WITH_INFO) {
 					ZVAL_STRINGL(&tmp, buf, result->longreadlen);
+				} else if (rc != SQL_SUCCESS) {
+					php_error_docref(NULL, E_WARNING, "Cannot get data of column #%d (retcode %u)", i + 1, rc);
+					ZVAL_FALSE(&tmp);
 				} else if (result->values[i].vallen == SQL_NULL_DATA) {
 					ZVAL_NULL(&tmp);
 					break;
@@ -2199,12 +2205,13 @@ PHP_FUNCTION(odbc_result)
 				RETURN_FALSE;
 			}
 
-			if (result->values[field_ind].vallen == SQL_NULL_DATA) {
-				zend_string_efree(field_str);
-				RETURN_NULL();
-			} else if (rc == SQL_NO_DATA_FOUND) {
+			if (rc != SQL_SUCCESS && rc != SQL_SUCCESS_WITH_INFO) {
 				zend_string_efree(field_str);
+				php_error_docref(NULL, E_WARNING, "Cannot get data of column #%d (retcode %u)", field_ind + 1, rc);
 				RETURN_FALSE;
+			} else if (result->values[field_ind].vallen == SQL_NULL_DATA) {
+				zend_string_efree(field_str);
+				RETURN_NULL();
 			}
 			/* Reduce fieldlen by 1 if we have char data. One day we might
 			   have binary strings... */
@@ -2250,6 +2257,12 @@ PHP_FUNCTION(odbc_result)
 			RETURN_FALSE;
 		}
 
+		if (rc != SQL_SUCCESS && rc != SQL_SUCCESS_WITH_INFO) {
+			php_error_docref(NULL, E_WARNING, "Cannot get data of column #%d (retcode %u)", field_ind + 1, rc);
+			efree(field);
+			RETURN_FALSE;
+		}
+
 		if (result->values[field_ind].vallen == SQL_NULL_DATA) {
 			efree(field);
 			RETURN_NULL();
@@ -2359,6 +2372,11 @@ PHP_FUNCTION(odbc_result_all)
 					}
 					if (rc == SQL_SUCCESS_WITH_INFO) {
 						PHPWRITE(buf, result->longreadlen);
+					} else if (rc != SQL_SUCCESS) {
+						php_printf("</td></tr></table>");
+						php_error_docref(NULL, E_WARNING, "Cannot get data of column #%d (retcode %u)", i + 1, rc);
+						efree(buf);
+						RETURN_FALSE;
 					} else if (result->values[i].vallen == SQL_NULL_DATA) {
 						php_printf("<td>NULL</td>");
 						break;
diff --git a/ext/odbc/tests/bug44618.phpt b/ext/odbc/tests/bug44618.phpt
new file mode 100644
index 0000000000..668cee7afa
--- /dev/null
+++ b/ext/odbc/tests/bug44618.phpt
@@ -0,0 +1,62 @@
+--TEST--
+Bug #44618 (Fetching may rely on uninitialized data)
+--SKIPIF--
+<?php include 'skipif.inc'; ?>
+--FILE--
+<?php
+include __DIR__ . "/config.inc";
+$conn = odbc_connect($dsn, $user, $pass, SQL_CUR_USE_ODBC);
+
+odbc_exec($conn, "CREATE TABLE bug44618(ID INT, real1 REAL, text1 TEXT)");
+odbc_exec($conn, "INSERT INTO bug44618 VALUES (1, 10.0199995, 'testing 1,2,3')");
+
+$result = odbc_exec($conn, "SELECT * FROM bug44618");
+var_dump(odbc_fetch_array($result));
+$result = null;
+
+$result = odbc_exec($conn, "SELECT * FROM bug44618");
+odbc_fetch_into($result, $array);
+var_dump($array);
+$result = null;
+
+$result = odbc_exec($conn, "SELECT * FROM bug44618");
+odbc_fetch_row($result);
+var_dump(odbc_result($result, "text1"));
+$result = null;
+
+$result = odbc_exec($conn, "SELECT * FROM bug44618");
+odbc_result_all($result);
+$result = null;
+?>
+--CLEAN--
+<?php
+include __DIR__ . "/config.inc";
+$conn = odbc_connect($dsn, $user, $pass);
+odbc_exec($conn, "DROP TABLE bug44618");
+?>
+--EXPECTF--
+Warning: odbc_fetch_array(): Cannot get data of column #3 (retcode 100) in %s on line %d
+array(3) {
+  ["ID"]=>
+  string(1) "1"
+  ["real1"]=>
+  string(5) "10.02"
+  ["text1"]=>
+  bool(false)
+}
+
+Warning: odbc_fetch_into(): Cannot get data of column #3 (retcode 100) in %s on line %d
+array(3) {
+  [0]=>
+  string(1) "1"
+  [1]=>
+  string(5) "10.02"
+  [2]=>
+  bool(false)
+}
+
+Warning: odbc_result(): Cannot get data of column #3 (retcode 100) in %s on line %d
+bool(false)
+<table><tr><th>ID</th><th>real1</th><th>text1</th></tr>
+<tr><td>1</td><td>10.02</td><td></td></tr></table>
+Warning: odbc_result_all(): Cannot get data of column #3 (retcode 100) in %s on line %d
-- 
2.40.0