mod_php 8.1.26 crashes on apache graceful restart

Description

After updating from PHP 8.1.25 to 8.1.26 our apache24 servers started to crash from time-to-time on graceful restarts (e.g. after midnight log rotation).

Here is the core dump:

(lldb) target create "httpd" --core "httpd-86152.core"
Core file '/tmp/httpd-86152.core' (x86_64) was loaded.
(lldb) bt
* thread #1, name = 'httpd', stop reason = signal SIGSEGV
  * frame #0: 0x0000000801673170 libphp.so`zend_optimizer_compact_literals(op_array=0x0000000000000000, ctx=<unavailable>) at compact_literals.c:520:16
    frame #1: 0x00000008015ce1c6 libphp.so`zend_extension_startup(extension=0x0000000801150510) at zend_extensions.c:196:7
    frame #2: 0x00000008015b0ba1 libphp.so`zend_llist_apply_with_del(l=0x0000000801754100, func=(libphp.so`zend_extension_startup at zend_extensions.c:193)) at zend_llist.c:171:7
    frame #3: 0x00000008015ce1a8 libphp.so`zend_startup_extensions at zend_extensions.c:217:2 [artificial]
    frame #4: 0x000000080154f8c7 libphp.so`php_module_startup(sf=<unavailable>, additional_modules=<unavailable>, num_additional_modules=1) at main.c:2263:2
    frame #5: 0x00000008016ad385 libphp.so`php_apache2_startup(sapi_module=<unavailable>) at sapi_apache2.c:381:6
    frame #6: 0x00000008016acbd6 libphp.so`php_apache_server_startup(pconf=0x0000000800907028, plog=<unavailable>, ptemp=<unavailable>, s=<unavailable>) at sapi_apache2.c:495:6
    frame #7: 0x0000000000263d6f httpd`ap_run_post_config + 79
    frame #8: 0x000000000025f4cc httpd`main + 2476
    frame #9: 0x000000000025e910 httpd`_start + 256

PHP Version

PHP 8.1.26

Operating System

FreeBSD 12.4

compact_literals.c の 520 行目にあるクラッシュ箇所から始め、zend_extensions.c、main.c、sapi_apache2.c を通る拡張機能の起動パスを追跡します。FreeBSD 12.4 上の Apache で PHP 8.1.26 を使用して graceful restart 時のクラッシュを再現し、オプティマイザが null op_array を受け取る理由を特定します。このパスで graceful restart がクラッシュしなくなれば完了です。