[php-src] Issue #22448: Assertion failure at zend_fiber_suspend_internal

[email protected] (YuanchengJiang) Thu, 25 Jun 2026 08:07:18 +0000
Newsgroups php.bugs
Message-ID <[email protected]>
Issue: https://github.com/php/php-src/issues/22448
Author: YuanchengJiang

### Description

The following code:

```php
<?php
try {
$fiber = new Fiber(function() use ($gen, &$fiber) {
});
$fiber = new Fiber(function (): int {
$test = new _ZendTestFiber(function (): void {
$value = Fiber::suspend(1);
});
var_dump($test->start()); // NULL
});
$value = $fiber->start();
} catch (\Throwable $_ffl_e) {}
```

Resulted in this output:
```
php: /home/fuzz/WorkSpace/fusion-fuzz/projects/php/php-src/Zend/zend_fibers.c:701: zend_fiber_transfer zend_fiber_suspend_internal(zend_fiber *, zval *): Assertion `fiber->caller != ((void*)0)' failed.
Aborted (core dumped)
```

To reproduce:
```
/home/fuzz/WorkSpace/fusion-fuzz/projects/php/php-src/sapi/cli/php  ./test.php
```

Commit:
```
fd8eaaf153f958c66068e3bc71b950ee33cb56e8
```

Configurations:
```
CC="clang-12" CXX="clang++-12" CFLAGS="-DZEND_VERIFY_TYPE_INFERENCE" CXXFLAGS="-DZEND_VERIFY_TYPE_INFERENCE" ./configure --enable-debug --enable-address-sanitizer --enable-undefined-sanitizer --enable-re2c-cgoto --enable-fpm --enable-litespeed --enable-phpdbg-debug --enable-zts --enable-bcmath --enable-calendar --enable-dba --enable-dl-test --enable-exif --enable-ftp --enable-gd --enable-gd-jis-conv --enable-mbstring --enable-pcntl --enable-shmop --enable-soap --enable-sockets --enable-sysvmsg --enable-zend-test --with-zlib --with-bz2 --with-curl --with-enchant --with-gettext --with-gmp --with-mhash --with-ldap --with-libedit --with-readline --with-snmp --with-sodium --with-xsl --with-zip --with-mysqli --with-pdo-mysql --with-pdo-pgsql --with-pgsql --with-sqlite3 --with-pdo-sqlite --with-webp --with-jpeg --with-freetype --enable-sigchild --with-readline --with-pcre-jit --with-iconv
```

Operating System:
```
Ubuntu 20.04 Host, Docker 0599jiangyc/flowfusion:latest
```

*This bug was found by [fusion-fuzz](https://github.com/fusion-fuzz/fusion-fuzz)*

### PHP Version

```plain
nightly
```

### Operating System

_No response_