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Fix GH-25263: Use-after-free of __call trampoline when cloning CurlHandle #25273

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Fix GH-25263: Use-after-free of __call trampoline when cloning CurlHandle #25273

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21 changes: 17 additions & 4 deletions ext/curl/interface.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1284,10 +1284,23 @@ PHP_FUNCTION(curl_init)
}
/* }}} */

static void php_curl_fcc_dup(zend_fcall_info_cache *dest, const zend_fcall_info_cache *src)
{
zend_fcc_dup(dest, src);
/* Each FCC owns its trampoline copy, so the duplicate needs its own */
if (UNEXPECTED(dest->function_handler->common.fn_flags & ZEND_ACC_CALL_VIA_TRAMPOLINE)) {
zend_function *copy = emalloc(sizeof(zend_function));

memcpy(copy, src->function_handler, sizeof(zend_function));
zend_string_addref(copy->common.function_name);
dest->function_handler = copy;
}
}

static void php_curl_copy_fcc_with_option(php_curl *ch, CURLoption option, zend_fcall_info_cache *target_fcc, zend_fcall_info_cache *source_fcc)
{
if (ZEND_FCC_INITIALIZED(*source_fcc)) {
zend_fcc_dup(target_fcc, source_fcc);
php_curl_fcc_dup(target_fcc, source_fcc);
}

/* The callback data (i.e. pointer to the curl handle) stays even if a user callback
Expand Down Expand Up @@ -1323,13 +1336,13 @@ void _php_setup_easy_copy_handlers(php_curl *ch, php_curl *source)
ch->handlers.read->res = source->handlers.read->res;

if (ZEND_FCC_INITIALIZED(source->handlers.read->fcc)) {
zend_fcc_dup(&ch->handlers.read->fcc, &source->handlers.read->fcc);
php_curl_fcc_dup(&ch->handlers.read->fcc, &source->handlers.read->fcc);
}
if (ZEND_FCC_INITIALIZED(source->handlers.write->fcc)) {
zend_fcc_dup(&ch->handlers.write->fcc, &source->handlers.write->fcc);
php_curl_fcc_dup(&ch->handlers.write->fcc, &source->handlers.write->fcc);
}
if (ZEND_FCC_INITIALIZED(source->handlers.write_header->fcc)) {
zend_fcc_dup(&ch->handlers.write_header->fcc, &source->handlers.write_header->fcc);
php_curl_fcc_dup(&ch->handlers.write_header->fcc, &source->handlers.write_header->fcc);
}

curl_easy_setopt(ch->cp, CURLOPT_ERRORBUFFER, ch->err.str);
Expand Down
28 changes: 28 additions & 0 deletions ext/curl/tests/gh25263.phpt
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Original file line number Diff line number Diff line change
@@ -0,0 +1,28 @@
--TEST--
GH-25263 (Use-after-free of __call trampoline when cloning CurlHandle)
--EXTENSIONS--
curl
--FILE--
<?php
class T {
public function __call($name, $args) {
echo $name, PHP_EOL;
return strlen($args[1]);
}
}

$ch = curl_init('file://' . __FILE__);
curl_setopt($ch, CURLOPT_WRITEFUNCTION, [new T, 'trampoline']);
$ch2 = clone $ch;
unset($ch);
curl_exec($ch2);

$ch = curl_init();
curl_setopt($ch, CURLOPT_READFUNCTION, [new T, 'trampoline']);
$ch2 = clone $ch;
unset($ch2);
echo "Done\n";
?>
--EXPECT--
trampoline
Done
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