Bug #80246 [NEW]: SEGV in zend_fetch_dimension_address_read()
From: sanjeev dot das at ibm dot com
Operating system: 18.04.4 LTS
PHP version: 7.4.11
Package: CGI/CLI related
Bug Type: Bug
Bug description:SEGV in zend_fetch_dimension_address_read()
Description:
------------
Segmentation fault is triggered due to null pointer dereference in
zend_fetch_dimension_address_read() with the given php script.
Address sanitizer shows:
AddressSanitizer:DEADLYSIGNAL
=================================================================
==4575==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000010
(pc 0x0000016c426a bp 0x7fff1318b790 sp 0x7fff1318af60 T0)
==4575==The signal is caused by a READ memory access.
==4575==Hint: address points to the zero page.
#0 0x16c4269 in zend_fetch_dimension_address_read
php-7.2.34/Zend/zend_execute.c:1800:7
#1 0x16c4269 in zend_fetch_dimension_address_read_R_slow
php-7.2.34/Zend/zend_execute.c:1855
#2 0x1379a9b in ZEND_FETCH_DIM_R_SPEC_CV_CONST_HANDLER
php-7.2.34/Zend/zend_vm_execute.h:36219:4
#3 0x11f2aad in execute_ex
php-7.2.34/Zend/zend_vm_execute.h:59767:7
#4 0x11f3e92 in zend_execute
php-7.2.34/Zend/zend_vm_execute.h:63804:2
#5 0xfd7e9b in zend_execute_scripts php-7.2.34/Zend/zend.c:1498:4
#6 0xd4a23a in php_execute_script php-7.2.34/main/main.c:2599:14
#7 0x171d99f in do_cli php-7.2.34/sapi/cli/php_cli.c:1011:5
#8 0x171ab8b in main php-7.2.34/sapi/cli/php_cli.c:1403:18
#9 0x7fafaac66b96 in __libc_start_main
/build/glibc-OTsEL5/glibc-2.27/csu/../csu/libc-start.c:310
#10 0x432279 in _start (php-7.2.34/sapi/cli/php+0x432279)
AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV php-7.2.34/Zend/zend_execute.c:1800:7 in
zend_fetch_dimension_address_read
==4575==ABORTING
Test script:
---------------
<?php
$my_var = null;
set_error_handler(function() use(&$my_var) {
$my_var = 0;
});
$my_var[] .= "xyz";
var_dump($my_var);
$my_var = null;
$my_var[0][0][0] .= "xyz";
var_dump($my_var);
$my_var = nual;
$my_var["foo"] . "xyz";
var_dump($my_var);
$my_Var = null;
$my_var["foo"]["bar"]["baz"] .= "xyz";
var_dump($my_var);
?>
Expected result:
----------------
No seg fault.
Actual result:
--------------
Segmentation fault.
--
Edit bug report at https://bugs.php.net/bug.php?id=80246&edit=1
--
Fix committed: https://bugs.php.net/fix.php?id=80246&r=fixed
Fixed in release: https://bugs.php.net/fix.php?id=80246&r=alreadyfixed
Need backtrace: https://bugs.php.net/fix.php?id=80246&r=needtrace
Need Reproduce Script: https://bugs.php.net/fix.php?id=80246&r=needscript
Try newer version: https://bugs.php.net/fix.php?id=80246&r=oldversion
Not developer issue: https://bugs.php.net/fix.php?id=80246&r=support
Expected behavior: https://bugs.php.net/fix.php?id=80246&r=notwrong
Not enough info: https://bugs.php.net/fix.php?id=80246&r=notenoughinfo
Submitted twice: https://bugs.php.net/fix.php?id=80246&r=submittedtwice
register_globals: https://bugs.php.net/fix.php?id=80246&r=globals
PHP version support discontinued: https://bugs.php.net/fix.php?id=80246&r=phptooold
Daylight Savings: https://bugs.php.net/fix.php?id=80246&r=dst
IIS Stability: https://bugs.php.net/fix.php?id=80246&r=isapi
Install GNU Sed: https://bugs.php.net/fix.php?id=80246&r=gnused
Floating point limitations: https://bugs.php.net/fix.php?id=80246&r=float
No Zend Extensions: https://bugs.php.net/fix.php?id=80246&r=nozend
MySQL Configuration Error: https://bugs.php.net/fix.php?id=80246&r=mysqlcfg
Thread (3 messages)
- sanjeev dot das at ibm dot com