Fix phpGH-9032: SQLite3 authorizer crashes on NULL values

The arguments 3 to 6 of the authorizer callback may be `NULL`[1], and
we have to properly deal with that.  Instead of causing a segfault, we
deny authorization, which is still better than a crash, and apparently,
we cannot do better anyway.

[1] <https://www.sqlite.org/c3ref/set_authorizer.html>

Closes phpGH-9040.

Author: cmb69

NEWS

@@ -11,6 +11,12 @@ PHP                                                                        NEWS
   . Fixed bug GH-9033 (Loading blacklist file can fail due to negative length).
     (cmb)
 
+- PDO_SQLite:
+  . Fixed bug GH-9032 (SQLite3 authorizer crashes on NULL values). (cmb)
+
+- SQLite3:
+  . Fixed bug GH-9032 (SQLite3 authorizer crashes on NULL values). (cmb)
+
 - Standard:
   . Fixed bug GH-9017 (php_stream_sock_open_from_socket could return NULL).
     (Heiko Weber)

ext/pdo_sqlite/sqlite_driver.c

@@ -715,6 +715,9 @@ static const struct pdo_dbh_methods sqlite_methods = {
 
 static char *make_filename_safe(const char *filename)
 {
+	if (!filename) {
+		return NULL;
+	}
 	if (*filename && memcmp(filename, ":memory:", sizeof(":memory:"))) {
 		char *fullpath = expand_filepath(filename, NULL);
 
@@ -737,7 +740,7 @@ static int authorizer(void *autharg, int access_type, const char *arg3, const ch
 	char *filename;
 	switch (access_type) {
 		case SQLITE_COPY: {
-					filename = make_filename_safe(arg4);
+			filename = make_filename_safe(arg4);
 			if (!filename) {
 				return SQLITE_DENY;
 			}
@@ -746,7 +749,7 @@ static int authorizer(void *autharg, int access_type, const char *arg3, const ch
 		}
 
 		case SQLITE_ATTACH: {
-					filename = make_filename_safe(arg3);
+			filename = make_filename_safe(arg3);
 			if (!filename) {
 				return SQLITE_DENY;
 			}

ext/pdo_sqlite/tests/gh9032.phpt

@@ -0,0 +1,26 @@
+--TEST--
+SQLite3 authorizer crashes on NULL values
+--SKIPIF--
+<?php
+if (!extension_loaded("pdo_sqlite")) die("skip pdo_sqlite extension not available");
+?>
+--INI--
+open_basedir=.
+--FILE--
+<?php
+$db = new PDO("sqlite::memory:", null, null, [PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION]);
+
+$db->exec('attach database \':memory:\' AS "db1"');
+var_dump($db->exec('create table db1.r (id int)'));
+
+try {
+$st = $db->prepare('attach database :a AS "db2"');
+$st->execute([':a' => ':memory:']);
+var_dump($db->exec('create table db2.r (id int)'));
+} catch (PDOException $ex) {
+    echo $ex->getMessage(), PHP_EOL;
+}
+?>
+--EXPECT--
+int(0)
+SQLSTATE[HY000]: General error: 23 not authorized

ext/sqlite3/sqlite3.c

@@ -2049,6 +2049,9 @@ static int php_sqlite3_authorizer(void *autharg, int action, const char *arg1, c
 	/* Check open_basedir restrictions first */
 	if (PG(open_basedir) && *PG(open_basedir)) {
 		if (action == SQLITE_ATTACH) {
+			if (!arg1) {
+				return SQLITE_DENY;
+			}
 			if (memcmp(arg1, ":memory:", sizeof(":memory:")) && *arg1) {
 				if (strncmp(arg1, "file:", 5) == 0) {
 					/* starts with "file:" */

ext/sqlite3/tests/gh9032.phpt

@@ -0,0 +1,28 @@
+--TEST--
+SQLite3 authorizer crashes on NULL values
+--SKIPIF--
+<?php
+if (!extension_loaded("sqlite3")) die("skip sqlite3 extension not available");
+?>
+--INI--
+open_basedir=.
+--FILE--
+<?php
+$db = new SQLite3(":memory:");
+$db->enableExceptions(true);
+
+$db->exec('attach database \':memory:\' AS "db1"');
+var_dump($db->exec('create table db1.r (id int)'));
+
+try {
+    $st = $db->prepare('attach database :a AS "db2"');
+    $st->bindValue("a", ":memory:");
+    $st->execute();
+    var_dump($db->exec('create table db2.r (id int)'));
+} catch (Exception $ex) {
+    echo $ex->getMessage(), PHP_EOL;
+}
+?>
+--EXPECT--
+bool(true)
+Unable to prepare statement: 23, not authorized