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SCCP causes UAF for return value if both warning and exception are triggered #19792

Description

@chongwick

Description

The following code:

<?php
function stringAsHex($v_37384=5,)
{
$v_37279 = $v_37279;
$col = 0;
$v_37369 = NULL;
$v_37281 = unpack($col,$v_37369,);
}

Resulted in this output:

==35==ERROR: AddressSanitizer: heap-use-after-free on address 0x606000064700 at pc 0x00000685075f bp 0x7fff8cde2f70 sp 0x7fff8cde2f68
READ of size 4 at 0x606000064700 thread T0
    #0 0x685075e in zend_gc_delref /home/w023dtc/nightly_php/php-src/Zend/zend_types.h:1383:2
    #1 0x685032c in i_zval_ptr_dtor /home/w023dtc/nightly_php/php-src/Zend/zend_variables.h:44:8
    #2 0x68500f4 in zval_ptr_dtor /home/w023dtc/nightly_php/php-src/Zend/zend_variables.c:84:2
    #3 0x53f10ba in ct_eval_func_call_ex /home/w023dtc/nightly_php/php-src/Zend/Optimizer/sccp.c:844:3
    #4 0x53ef192 in ct_eval_func_call /home/w023dtc/nightly_php/php-src/Zend/Optimizer/sccp.c:860:9
    #5 0x53d5a07 in sccp_visit_instr /home/w023dtc/nightly_php/php-src/Zend/Optimizer/sccp.c:1697:8
    #6 0x540e3a8 in scdf_solve /home/w023dtc/nightly_php/php-src/Zend/Optimizer/scdf.c:166:7
    #7 0x53b59b4 in sccp_optimize_op_array /home/w023dtc/nightly_php/php-src/Zend/Optimizer/sccp.c:2482:2
    #8 0x530a659 in zend_dfa_optimize_op_array /home/w023dtc/nightly_php/php-src/Zend/Optimizer/dfa_pass.c:1056:8
    #9 0x5687033 in zend_optimize_script /home/w023dtc/nightly_php/php-src/Zend/Optimizer/zend_optimizer.c:1644:5
    #10 0x23ff960 in cache_script_in_shared_memory /home/w023dtc/nightly_php/php-src/ext/opcache/ZendAccelerator.c:1582:2
    #11 0x23ee754 in persistent_compile_file /home/w023dtc/nightly_php/php-src/ext/opcache/ZendAccelerator.c:2186:24
    #12 0x68ab6c0 in zend_execute_script /home/w023dtc/nightly_php/php-src/Zend/zend.c:1970:28
    #13 0x508da3a in php_execute_script_ex /home/w023dtc/nightly_php/php-src/main/main.c:2638:13
    #14 0x508eb78 in php_execute_script /home/w023dtc/nightly_php/php-src/main/main.c:2678:9
    #15 0x68c07ea in do_cli /home/w023dtc/nightly_php/php-src/sapi/cli/php_cli.c:951:5
    #16 0x68babcf in main /home/w023dtc/nightly_php/php-src/sapi/cli/php_cli.c:1362:18
    #17 0x14719485dd8f in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16
    #18 0x14719485de3f in __libc_start_main csu/../csu/libc-start.c:392:3
    #19 0x6061f4 in _start (/home/php+0x6061f4)

0x606000064700 is located 0 bytes inside of 56-byte region [0x606000064700,0x606000064738)
freed by thread T0 here:
    #0 0x680e52 in free (/home/php+0x680e52)
    #1 0x56f5dc3 in __zend_free /home/w023dtc/nightly_php/php-src/Zend/zend_alloc.c:3571:2
    #2 0x5700e7b in _efree /home/w023dtc/nightly_php/php-src/Zend/zend_alloc.c:2790:3
    #3 0x637d327 in zend_array_destroy /home/w023dtc/nightly_php/php-src/Zend/zend_hash.c:1872:2
    #4 0x68500b7 in rc_dtor_func /home/w023dtc/nightly_php/php-src/Zend/zend_variables.c:57:2
    #5 0x685033e in i_zval_ptr_dtor /home/w023dtc/nightly_php/php-src/Zend/zend_variables.h:45:4
    #6 0x68500f4 in zval_ptr_dtor /home/w023dtc/nightly_php/php-src/Zend/zend_variables.c:84:2
    #7 0x53f0ef7 in ct_eval_func_call_ex /home/w023dtc/nightly_php/php-src/Zend/Optimizer/sccp.c:838:3
    #8 0x53ef192 in ct_eval_func_call /home/w023dtc/nightly_php/php-src/Zend/Optimizer/sccp.c:860:9
    #9 0x53d5a07 in sccp_visit_instr /home/w023dtc/nightly_php/php-src/Zend/Optimizer/sccp.c:1697:8
    #10 0x540e3a8 in scdf_solve /home/w023dtc/nightly_php/php-src/Zend/Optimizer/scdf.c:166:7
    #11 0x53b59b4 in sccp_optimize_op_array /home/w023dtc/nightly_php/php-src/Zend/Optimizer/sccp.c:2482:2
    #12 0x530a659 in zend_dfa_optimize_op_array /home/w023dtc/nightly_php/php-src/Zend/Optimizer/dfa_pass.c:1056:8
    #13 0x5687033 in zend_optimize_script /home/w023dtc/nightly_php/php-src/Zend/Optimizer/zend_optimizer.c:1644:5
    #14 0x23ff960 in cache_script_in_shared_memory /home/w023dtc/nightly_php/php-src/ext/opcache/ZendAccelerator.c:1582:2
    #15 0x23ee754 in persistent_compile_file /home/w023dtc/nightly_php/php-src/ext/opcache/ZendAccelerator.c:2186:24
    #16 0x68ab6c0 in zend_execute_script /home/w023dtc/nightly_php/php-src/Zend/zend.c:1970:28
    #17 0x508da3a in php_execute_script_ex /home/w023dtc/nightly_php/php-src/main/main.c:2638:13
    #18 0x508eb78 in php_execute_script /home/w023dtc/nightly_php/php-src/main/main.c:2678:9
    #19 0x68c07ea in do_cli /home/w023dtc/nightly_php/php-src/sapi/cli/php_cli.c:951:5
    #20 0x68babcf in main /home/w023dtc/nightly_php/php-src/sapi/cli/php_cli.c:1362:18
    #21 0x14719485dd8f in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16

previously allocated by thread T0 here:
    #0 0x6810bd in malloc (/home/php+0x6810bd)
    #1 0x5702133 in __zend_malloc /home/w023dtc/nightly_php/php-src/Zend/zend_alloc.c:3543:14
    #2 0x5700899 in _emalloc /home/w023dtc/nightly_php/php-src/Zend/zend_alloc.c:2780:10
    #3 0x633a46a in _zend_new_array /home/w023dtc/nightly_php/php-src/Zend/zend_hash.c:290:18
    #4 0x43a4d75 in zif_unpack /home/w023dtc/nightly_php/php-src/ext/standard/pack.c:707:2
    #5 0x53f0c22 in ct_eval_func_call_ex /home/w023dtc/nightly_php/php-src/Zend/Optimizer/sccp.c:831:2
    #6 0x53ef192 in ct_eval_func_call /home/w023dtc/nightly_php/php-src/Zend/Optimizer/sccp.c:860:9
    #7 0x53d5a07 in sccp_visit_instr /home/w023dtc/nightly_php/php-src/Zend/Optimizer/sccp.c:1697:8
    #8 0x540e3a8 in scdf_solve /home/w023dtc/nightly_php/php-src/Zend/Optimizer/scdf.c:166:7
    #9 0x53b59b4 in sccp_optimize_op_array /home/w023dtc/nightly_php/php-src/Zend/Optimizer/sccp.c:2482:2
    #10 0x530a659 in zend_dfa_optimize_op_array /home/w023dtc/nightly_php/php-src/Zend/Optimizer/dfa_pass.c:1056:8
    #11 0x5687033 in zend_optimize_script /home/w023dtc/nightly_php/php-src/Zend/Optimizer/zend_optimizer.c:1644:5
    #12 0x23ff960 in cache_script_in_shared_memory /home/w023dtc/nightly_php/php-src/ext/opcache/ZendAccelerator.c:1582:2
    #13 0x23ee754 in persistent_compile_file /home/w023dtc/nightly_php/php-src/ext/opcache/ZendAccelerator.c:2186:24
    #14 0x68ab6c0 in zend_execute_script /home/w023dtc/nightly_php/php-src/Zend/zend.c:1970:28
    #15 0x508da3a in php_execute_script_ex /home/w023dtc/nightly_php/php-src/main/main.c:2638:13
    #16 0x508eb78 in php_execute_script /home/w023dtc/nightly_php/php-src/main/main.c:2678:9
    #17 0x68c07ea in do_cli /home/w023dtc/nightly_php/php-src/sapi/cli/php_cli.c:951:5
    #18 0x68babcf in main /home/w023dtc/nightly_php/php-src/sapi/cli/php_cli.c:1362:18
    #19 0x14719485dd8f in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16

SUMMARY: AddressSanitizer: heap-use-after-free /home/w023dtc/nightly_php/php-src/Zend/zend_types.h:1383:2 in zend_gc_delref
Shadow bytes around the buggy address:
  0x0c0c80004890: fd fd fd fa fa fa fa fa fd fd fd fd fd fd fd fd
  0x0c0c800048a0: fa fa fa fa fd fd fd fd fd fd fd fd fa fa fa fa
  0x0c0c800048b0: 00 00 00 00 00 00 00 fa fa fa fa fa fd fd fd fd
  0x0c0c800048c0: fd fd fd fd fa fa fa fa 00 00 00 00 00 00 00 00
  0x0c0c800048d0: fa fa fa fa 00 00 00 00 00 00 00 00 fa fa fa fa
=>0x0c0c800048e0:[fd]fd fd fd fd fd fd fa fa fa fa fa fd fd fd fd
  0x0c0c800048f0: fd fd fd fa fa fa fa fa fd fd fd fd fd fd fd fa
  0x0c0c80004900: fa fa fa fa fd fd fd fd fd fd fd fa fa fa fa fa
  0x0c0c80004910: fd fd fd fd fd fd fd fd fa fa fa fa fa fa fa fa
  0x0c0c80004920: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c0c80004930: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
Shadow byte legend (one shadow byte represents 8 application bytes):
  Addressable:           00
  Partially addressable: 01 02 03 04 05 06 07
  Heap left redzone:       fa
  Freed heap region:       fd
  Stack left redzone:      f1
  Stack mid redzone:       f2
  Stack right redzone:     f3
  Stack after return:      f5
  Stack use after scope:   f8
  Global redzone:          f9
  Global init order:       f6
  Poisoned by user:        f7
  Container overflow:      fc
  Array cookie:            ac
  Intra object redzone:    bb
  ASan internal:           fe
  Left alloca redzone:     ca
  Right alloca redzone:    cb
  Shadow gap:              cc
==35==ABORTING

USE_ZEND_ALLOC=0 ./php -d "opcache.enable=1" -d "opcache.enable_cli=1" -d "opcache.jit_buffer_size=256M" -d "opcache.jit=1254" -d "opcache.jit_hot_func=1" -d "opcache.jit_hot_loop=1" -d "opcache.jit_hot_return=1" -d "opcache.jit_hot_side_exit=1" script.php

PHP Version

nightly

Operating System

ubuntu 22.04

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