[php-src] Issue #13680: Segfault from ASan: SEGV on unknown address 0x7ffd00000042

Issue: https://github.com/php/php-src/issues/13680 Author: YuanchengJiang ### Description Given the following phpt file: ``` --TEST-- ASan DEADLYSIGNAL SEGV on unknown address --INI-- error_reporting=E_ALL&~E_DEPRECATED --FILE-- <?php class obj implements Serializable { var $data; function serialize() { return serialize($this->data); } function unserialize($data) { session_start(); session_decode($data); } } $inner = 'ryat|a:1:{i:0;a:1:{i:1;'; $exploit = 'a:2:{i:0;C:3:"obj":'.strlen($inner).':{'.$inner.'}i:1;R:4;}'; $data = unserialize($exploit); for ($i = 0; $i < 5; $i++) { $v[$i] = 'hi'.$i; } var_dump($data); ?> <?php enum Foo { case Bar; public function __sleep(): array { } } ?> --EXTENSIONS-- session --EXPECTF-- Warning: session_decode(): Failed to decode session object. Session has been destroyed in %s on line %d Warning: unserialize(): Error at offset 55 of 56 bytes in %s on line %d bool(false) Fatal error: Enum Foo cannot include magic method __sleep in %s on line %d ``` Resulted in this output: ``` AddressSanitizer:DEADLYSIGNAL ================================================================= ==491976==ERROR: AddressSanitizer: SEGV on unknown address 0x7ffd00000042 (pc 0x7f26f2481205 bp 0x0000ffffffff sp 0x7ffdf94bc550 T0) ==491976==The signal is caused by a READ memory access. #0 0x7f26f2481205 in _longjmp (/lib/x86_64-linux-gnu/libc.so.6+0x42205) (BuildId: c289da5071a3399de893d2af81d6a30c62646e1e) #1 0x565537b6fad8 in _zend_bailout /WorkSpace/php-src/Zend/zend.c:1226:2 #2 0x565536dd1c3f in php_session_decode /WorkSpace/php-src/ext/session/session.c:282:3 #3 0x7f26ed27f59f (<unknown module>) AddressSanitizer can not provide additional info. SUMMARY: AddressSanitizer: SEGV (/lib/x86_64-linux-gnu/libc.so.6+0x42205) (BuildId: c289da5071a3399de893d2af81d6a30c62646e1e) in _longjmp ``` ### PHP Version PHP 8.4.0-dev ### Operating System ubuntu 22.04