Bug #79548 [NEW]: Segfault when using static inline variable inside a trait

From: luca at sungazer dot io Operating system: Linux PHP version: 7.4.5 Package: opcache Bug Type: Bug Bug description:Segfault when using static inline variable inside a trait Description: ------------ Configuration: * Custom image built from https://hub.docker.com/_/php * Nginx + PHP-FPM * Symfony 5.0.8 * PHP 7.4.5 * Preloading enabled (preload file generated by Symfony) Description: When using the Symfony Cache component, php-fpm was terminating with SIGSEGV whenever I wanted to call the cache get() method. This happened only when preloading was enabled. After further investigation, I saw that the segmentation fault happens at this line of Symfony's ContractsTrait https://github.com/symfony/symfony/blob/master/src/Symfony/Component/Cache/Traits/ContractsTrait.php#L58 i.e. at the declaration of a static variable inside a private method of a Trait. A similar issue was reported on Symfony's issue list as well: https://github.com/symfony/symfony/issues/36328 As a workaround, I tried moving the declaration outside the function (i.e. at trait level private static $setMetadata) and then code started working as intended. Disabling preloading also fixes the issue. Test script: --------------- Please see the following repository: https://github.com/luca-nardelli/symfony-cache-segfault-reproducer/tree/master -- Edit bug report at https://bugs.php.net/bug.php?id=79548&edit=1 -- Fix committed: https://bugs.php.net/fix.php?id=79548&r=fixed Fixed in release: https://bugs.php.net/fix.php?id=79548&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=79548&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=79548&r=needscript Try newer version: https://bugs.php.net/fix.php?id=79548&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=79548&r=support Expected behavior: https://bugs.php.net/fix.php?id=79548&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=79548&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=79548&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=79548&r=globals PHP version support discontinued: https://bugs.php.net/fix.php?id=79548&r=phptooold Daylight Savings: https://bugs.php.net/fix.php?id=79548&r=dst IIS Stability: https://bugs.php.net/fix.php?id=79548&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=79548&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=79548&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=79548&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=79548&r=mysqlcfg