Heap buffer overflow in DOMNode -> getElementByTagName

[chibinz]

Description

The following code:

<?php
$v10 = new DOMElement ( "a" );
$v10 -> getElementsByTagName ( "text\0something" );

Resulted in this output:

==1323436==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x602000003f95 at pc 0x55dbf218d627 bp 0x7fff76326f40 sp 0x7fff76326f38
READ of size 1 at 0x602000003f95 thread T0
    #0 0x55dbf218d626 in zend_str_tolower_impl /tmp/php-asan/Zend/zend_operators.c:2946:10
    #1 0x55dbf218e000 in zend_str_tolower /tmp/php-asan/Zend/zend_operators.c:3003:2
    #2 0x55dbf0fce3d3 in dom_namednode_iter /tmp/php-asan/ext/dom/php_dom.c:1488:4
    #3 0x55dbf0f3dfe3 in dom_element_get_elements_by_tag_name /tmp/php-asan/ext/dom/element.c:831:2
    #4 0x55dbf0f3db5e in zim_DOMElement_getElementsByTagName /tmp/php-asan/ext/dom/element.c:836:2
    #5 0x55dbf1e93ac2 in ZEND_DO_FCALL_SPEC_RETVAL_UNUSED_HANDLER /tmp/php-asan/Zend/zend_vm_execute.h:1919:4
    #6 0x55dbf1da602d in execute_ex /tmp/php-asan/Zend/zend_vm_execute.h:58565:7
    #7 0x55dbf1da6857 in zend_execute /tmp/php-asan/Zend/zend_vm_execute.h:64217:2
    #8 0x55dbf21da9d0 in zend_execute_script /tmp/php-asan/Zend/zend.c:1928:3
    #9 0x55dbf19f961b in php_execute_script_ex /tmp/php-asan/main/main.c:2574:13
    #10 0x55dbf19f9b18 in php_execute_script /tmp/php-asan/main/main.c:2614:9
    #11 0x55dbf21e2479 in do_cli /tmp/php-asan/sapi/cli/php_cli.c:935:5
    #12 0x55dbf21df49c in main /tmp/php-asan/sapi/cli/php_cli.c:1310:18
    #13 0x7f5e67629d8f  (/lib/x86_64-linux-gnu/libc.so.6+0x29d8f) (BuildId: 490fef8403240c91833978d494d39e537409b92e)
    #14 0x7f5e67629e3f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e3f) (BuildId: 490fef8403240c91833978d494d39e537409b92e)
    #15 0x55dbf0c02dc4 in _start (/workspaces/TriFuzz/targets/php-asan/bin/php+0x402dc4)

0x602000003f95 is located 0 bytes to the right of 5-byte region [0x602000003f90,0x602000003f95)
allocated by thread T0 here:
    #0 0x55dbf0c8798e in malloc /opt/llvm-15-build/llvm-15.x/final/llvm-project/compiler-rt/lib/asan/asan_malloc_linux.cpp:69:3
    #1 0x55dbf1c3a543 in __zend_malloc /tmp/php-asan/Zend/zend_alloc.c:3280:14
    #2 0x55dbf1c39ed0 in _emalloc /tmp/php-asan/Zend/zend_alloc.c:2737:10
    #3 0x55dbf1c3a7eb in _estrdup /tmp/php-asan/Zend/zend_alloc.c:2818:15
    #4 0x55dbf0fce2ba in dom_namednode_iter /tmp/php-asan/ext/dom/php_dom.c:1484:34
    #5 0x55dbf0f3dfe3 in dom_element_get_elements_by_tag_name /tmp/php-asan/ext/dom/element.c:831:2
    #6 0x55dbf0f3db5e in zim_DOMElement_getElementsByTagName /tmp/php-asan/ext/dom/element.c:836:2
    #7 0x55dbf1e93ac2 in ZEND_DO_FCALL_SPEC_RETVAL_UNUSED_HANDLER /tmp/php-asan/Zend/zend_vm_execute.h:1919:4
    #8 0x55dbf1da602d in execute_ex /tmp/php-asan/Zend/zend_vm_execute.h:58565:7
    #9 0x55dbf1da6857 in zend_execute /tmp/php-asan/Zend/zend_vm_execute.h:64217:2
    #10 0x55dbf21da9d0 in zend_execute_script /tmp/php-asan/Zend/zend.c:1928:3
    #11 0x55dbf19f961b in php_execute_script_ex /tmp/php-asan/main/main.c:2574:13
    #12 0x55dbf19f9b18 in php_execute_script /tmp/php-asan/main/main.c:2614:9
    #13 0x55dbf21e2479 in do_cli /tmp/php-asan/sapi/cli/php_cli.c:935:5
    #14 0x55dbf21df49c in main /tmp/php-asan/sapi/cli/php_cli.c:1310:18
    #15 0x7f5e67629d8f  (/lib/x86_64-linux-gnu/libc.so.6+0x29d8f) (BuildId: 490fef8403240c91833978d494d39e537409b92e)

SUMMARY: AddressSanitizer: heap-buffer-overflow /tmp/php-asan/Zend/zend_operators.c:2946:10 in zend_str_tolower_impl
Shadow bytes around the buggy address:
  0x0c047fff87a0: fa fa fd fd fa fa fd fd fa fa fd fd fa fa fd fd
  0x0c047fff87b0: fa fa fd fd fa fa fd fd fa fa fd fd fa fa fd fd
  0x0c047fff87c0: fa fa fd fd fa fa fd fd fa fa fd fd fa fa 00 04
  0x0c047fff87d0: fa fa 00 05 fa fa 00 05 fa fa 04 fa fa fa 00 fa
  0x0c047fff87e0: fa fa fd fd fa fa 00 04 fa fa 02 fa fa fa 00 07
=>0x0c047fff87f0: fa fa[05]fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff8800: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff8810: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff8820: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff8830: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff8840: 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
==1323436==ABORTING

PHP Version

PHP 8.5.0-dev

Operating System

No response