Fix GH-21639: Protect frameless implode args#21815
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prateekbhujel wants to merge 1 commit intophp:PHP-8.4from
Open
Fix GH-21639: Protect frameless implode args#21815prateekbhujel wants to merge 1 commit intophp:PHP-8.4from
prateekbhujel wants to merge 1 commit intophp:PHP-8.4from
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Fixes #21639
The frameless implode handlers borrow their operand zvals directly. If string conversion re-enters userland and clears the variables used for the separator or pieces, those borrowed values can be released while php_implode() is still using them.
Copy the frameless arguments before parsing them so the one-argument and two-argument handlers keep the same by-value lifetime guarantees as a normal call frame. The regression test covers mutation from an array element, mutation during separator conversion, and the one-argument form.
Tests:
ASAN build: ./configure --disable-all --enable-cli --enable-debug --without-pear --enable-address-sanitizer
run-tests.php -q ext/standard/tests/strings/gh21639.phpt ext/standard/tests/strings/implode_basic.phpt ext/standard/tests/strings/implode_variation.phpt ext/standard/tests/strings/join_basic.phpt