Free the hooked property value when json_encode() sees an exception - #22919
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Free the hooked property value when json_encode() sees an exception#22919iliaal wants to merge 1 commit into
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php_json_encode_array() reads a hooked property into a local zval and bails out when an exception is pending. The get hook can publish its return value into that zval and then throw while its frame is freed, for example from the destructor of one of its locals, so the bailout leaks the value until request shutdown. Destroy it on the way out, the way the other failure exit already does. Closes phpGH-22919
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TimWolla
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This looks like an obvious inconsistency with the php_json_encode_zval() error handling further below.
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A get hook can publish its return value into the zval json_encode() handed to zend_read_property_ex(), then throw while the engine tears the hook's frame down, for instance from the destructor of one of its locals. php_json_encode_array() returns on EG(exception) without destroying that zval, so the value survives to request shutdown. Twenty encodes of a hook returning a 1 MiB string retain 21 MB before the patch, 1.5 KB after.