Guard igbinary_serialize() against C stack overflow on deep nesting#416
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Guard igbinary_serialize() against C stack overflow on deep nesting#416iliaal wants to merge 1 commit intoigbinary:masterigbinary/igbinary:masterfrom iliaal:fix/serialize-stack-limitiliaal/igbinary:fix/serialize-stack-limitCopy head branch name to clipboard
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igbinary_serialize_zval() recurses once per nesting level with no depth or stack check, so a deeply nested array or object overflows the C stack and crashes the process. Mirror php_serialize_check_stack_limit() from ext/standard/var.c: check zend_call_stack_overflowed() at the top of the recursion and raise a catchable Error instead. No-op on builds without the Zend stack-limit feature (PHP < 8.3), matching core.
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igbinary_serialize_zval() recurses once per nesting level with no depth or stack-limit check, so a deep enough array or object overflows the C stack and segfaults the process. Core's serialize() guards the same recursion via php_serialize_check_stack_limit() (added in 8.3) and throws a catchable Error; igbinary crashes where core recovers. This is the serialize-side counterpart to the unserialize cap in #414.
Reproducer (segfaults before this change):
The fix checks zend_call_stack_overflowed(EG(stack_limit)) at the top of igbinary_serialize_zval() and raises via zend_call_stack_size_error(). No-op without ZEND_CHECK_STACK_LIMIT (PHP < 8.3), where core had no guard either. Test mirrors ext/standard/tests/serialize/gh15169.phpt.