** Description changed: + [Impact] + + As explained in https://www.php.net/manual/en/intro.opcache.php, + + OPcache improves PHP performance by storing precompiled bytecode in shared memory, removing the need to load and parse scripts on each request. + + A bug in PHP OPcache code (https://bugs.php.net/bug.php?id=79603) may + make PHP crash when this feature is enabled. For instance, this has been + observed with Symfony's caching feature. + + The fix is available upstream at https://github.com/php/php- + src/commit/4f47ba99f002d50e11c111b8625d81f79b2bf52f + + [Test Plan] + + Use the following script to reproduce the issue on a focal environment + with php7.4 installed: + + BEGIN_REPRODUCER + #!/bin/bash + + PHP_TMP_DIR="$(mktemp -d)" + PHP_CACHE_DIR="${PHP_TMP_DIR}/cache" + PHP_FILE1="${PHP_TMP_DIR}/file1.php" + PHP_FILE2="${PHP_TMP_DIR}/file2.php" + mkdir -p "${PHP_CACHE_DIR}" + + # prints information about the current php environment + # php -d opcache.enable_cli=1 -d opcache.file_cache_only=1 -d opcache.file_cache="${PHP_CACHE_DIR}" -i + + cat > "${PHP_FILE1}" <<EOF + <?php + return function() {}; + EOF + + cat > "${PHP_FILE2}" <<EOF + <?php + \$file = '${PHP_FILE1}'; + var_dump(include \$file); + touch(\$file); + var_dump(include \$file); + EOF + + sleep 5 + php -d opcache.enable_cli=1 -d opcache.file_cache_only=1 -d opcache.file_cache="${PHP_CACHE_DIR}" ${PHP_FILE1} + php -d opcache.enable_cli=1 -d opcache.file_cache_only=1 -d opcache.file_cache="${PHP_CACHE_DIR}" ${PHP_FILE2} + + # clean up + rm -rf "${PHP_TMP_DIR}" + END_REPRODUCER + + Re-run the reproducer after installing the proposed fix to ensure the + new package is no longer affected. + + [Where problems could occur] + + While the patch being proposed seems to be straightforward, it was + applied on top of two other patches in Zend/zend_compile.c and will be + back-ported (it does apply on different lines without changes). This may + lead to unpredicted code-paths being executed, triggering possible bugs + not seen upstream. + + The set of patches is small enough and if needed, we could apply the + whole set to make the codepaths closer to what upstream intended for PHP + 7.4.7. + + $ git log --oneline PHP-7.4.3..PHP-7.4.7 -- Zend/zend_compile.c + 4f47ba99f0 Fix bug #79603, by retrying on RTD key collision + c5159b3832 Check asserts early + 2dddab01ae Avoid "Anonymous class wasn't preloaded" error by lazely loading of not preloaded part of a preloaded script + + Moreover, recompiling PHP linking it to possible new versions of + libraries that may have been SRU'd could trigger unwanted behaviors + which were not observed before. + + [Other Info] + + This bug was fixed in php 7.4.7 and is not present in Ubuntu releases other than focal. + + [Original message] + As described in PHP bug #79603, it is possible to cause opcache collisions that result in a fatal error. https://bugs.php.net/bug.php?id=79603 It has been fixed in this upstream commit: https://github.com/php/php-src/commit/4f47ba99f002d50e11c111b8625d81f79b2bf52f The changes to zend_compile.c apply cleanly, just at different line numbers. This has been reproduced on Ubuntu 20.04 with version 7.4.3-4ubuntu2.8 of php7.4-opcache installed.
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1968228 Title: RTD collision with opcache To manage notifications about this bug go to: https://bugs.launchpad.net/php/+bug/1968228/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
