Fix leak+crash with sapi_windows_set_ctrl_handler() #18231
+52
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The ctrl_handler is never destroyed. We have to destroy it at request
end so we avoid leaking it and also avoid keeping a reference to
previous request memory in a next request. The latter can result in a
crash and can be demonstrated with this script and `--repeat 2`:
```php
class Test {
public function set() {
sapi_windows_set_ctrl_handler(self::cb(...));
}
public function cb() {
}
}
$test = new Test;
$test->set();
sleep(3);
```
When you hit CTRL+C in the second request you can crash.
This patch resolves both the leak and crash by destroying the
ctrl_handler after a request.
nielsdos
commented
Apr 2, 2025
| @@ -125,7 +144,7 @@ PHP_FUNCTION(sapi_windows_set_ctrl_handler) | |||
| RETURN_FALSE; | |||
| } | |||
|
|
|||
| zval_ptr_dtor_nogc(&ctrl_handler); | |||
| zval_ptr_dtor(&ctrl_handler); | |||
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This change is also a fix, this is needed because the handler closure object can be cyclic.
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The ctrl_handler is never destroyed. We have to destroy it at request end so we avoid leaking it and also avoid keeping a reference to previous request memory in a next request. The latter can result in a crash and can be demonstrated with this script and
--repeat 2:When you hit CTRL+C in the second request you can crash.
This patch resolves both the leak and crash by destroying the ctrl_handler after a request.