php / php/php-src

SEGV zend_jit_trace_copy_ssa_var_range

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Bug Category: JIT Extension: opcache Status: Needs Triage
Dominant language
C
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Description

Description

The following code:

<?php
$cls = new DateTime();
foo();
function foo() {
global $LAST;
}
$fusion = str_repeat('a', 1024 * 1024 * 1.25);
class DestructableObject
{
}
$_ = new DestructableObject();
try {$cls->getMicrosecond();} catch (Exception $e) { echo($e); }
try {$cls->getMicrosecond();} catch (Exception $e) { echo($e); }
try {$cls->getMicrosecond();} catch (Exception $e) { echo($e); }
try {$cls->getMicrosecond();} catch (Exception $e) { echo($e); }
try {$cls->getMicrosecond();} catch (Exception $e) { echo($e); }
try {$cls->getMicrosecond();} catch (Exception $e) { echo($e); }
try {$cls->getMicrosecond();} catch (Exception $e) { echo($e); }

Resulted in this output:

AddressSanitizer:DEADLYSIGNAL
=================================================================
==56999==ERROR: AddressSanitizer: SEGV on unknown address 0x77bab5571ca8 (pc 0x77c35b88db6e bp 0x7fff8033a630 sp 0x7fff80339ce0 T0)
==56999==The signal is caused by a READ memory access.
    #0 0x77c35b88db6e in zend_jit_trace_copy_ssa_var_range /home/phpfuzz/WorkSpace/flowfusion/php-src/ext/opcache/jit/zend_jit_trace.c:1004:36
    #1 0x77c35b6f317b in zend_jit_trace_build_tssa /home/phpfuzz/WorkSpace/flowfusion/php-src/ext/opcache/jit/zend_jit_trace.c:2276:6
    #2 0x77c35b54678c in zend_jit_trace /home/phpfuzz/WorkSpace/flowfusion/php-src/ext/opcache/jit/zend_jit_trace.c:4115:8
    #3 0x77c35b4903d6 in zend_jit_compile_root_trace /home/phpfuzz/WorkSpace/flowfusion/php-src/ext/opcache/jit/zend_jit_trace.c:7498:14
    #4 0x77c35b482327 in zend_jit_trace_hot_root /home/phpfuzz/WorkSpace/flowfusion/php-src/ext/opcache/jit/zend_jit_trace.c:8171:10
    #5 0x77c35b4472df in zend_jit_trace_counter_helper /home/phpfuzz/WorkSpace/flowfusion/php-src/ext/opcache/jit/zend_jit_vm_helpers.c:371:7
    #6 0x77c35b446920 in zend_jit_func_trace_helper /home/phpfuzz/WorkSpace/flowfusion/php-src/ext/opcache/jit/zend_jit_vm_helpers.c:394:2
    #7 0x4a00967 in execute_ex /home/phpfuzz/WorkSpace/flowfusion/php-src/Zend/zend_vm_execute.h:58595:7
    #8 0x4a02bec in zend_execute /home/phpfuzz/WorkSpace/flowfusion/php-src/Zend/zend_vm_execute.h:64247:2
    #9 0x57a3a79 in zend_execute_script /home/phpfuzz/WorkSpace/flowfusion/php-src/Zend/zend.c:1943:3
    #10 0x3f9945a in php_execute_script_ex /home/phpfuzz/WorkSpace/flowfusion/php-src/main/main.c:2584:13
    #11 0x3f9a598 in php_execute_script /home/phpfuzz/WorkSpace/flowfusion/php-src/main/main.c:2624:9
    #12 0x57b898a in do_cli /home/phpfuzz/WorkSpace/flowfusion/php-src/sapi/cli/php_cli.c:952:5
    #13 0x57b2d6f in main /home/phpfuzz/WorkSpace/flowfusion/php-src/sapi/cli/php_cli.c:1355:18
    #14 0x77c3628a1d8f in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16
    #15 0x77c3628a1e3f in __libc_start_main csu/../csu/libc-start.c:392:3
    #16 0x606174 in _start (/home/phpfuzz/WorkSpace/flowfusion/php-src/sapi/cli/php+0x606174)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV /home/phpfuzz/WorkSpace/flowfusion/php-src/ext/opcache/jit/zend_jit_trace.c:1004:36 in zend_jit_trace_copy_ssa_var_range
==56999==ABORTING

To reproduce:

./php-src/sapi/cli/php --repeat 2  -d "opcache.cache_id=worker29" -d "output_handler=" -d "open_basedir=" -d "disable_functions=" -d "output_buffering=Off" -d "error_reporting=30719" -d "display_errors=1" -d "display_startup_errors=1" -d "log_errors=0" -d "html_errors=0" -d "track_errors=0" -d "report_memleaks=1" -d "report_zend_debug=0" -d "docref_root=" -d "docref_ext=.html" -d "error_prepend_string=" -d "error_append_string=" -d "auto_prepend_file=" -d "auto_append_file=" -d "ignore_repeated_errors=0" -d "precision=14" -d "serialize_precision=-1" -d "memory_limit=2M" -d "opcache.fast_shutdown=0" -d "opcache.file_update_protection=0" -d "opcache.revalidate_freq=0" -d "opcache.jit_hot_loop=1" -d "opcache.jit_hot_func=1" -d "opcache.jit_hot_return=1" -d "opcache.jit_hot_side_exit=1" -d "opcache.jit_max_root_traces=100000" -d "opcache.jit_max_side_traces=100000" -d "opcache.jit_max_exit_counters=100000" -d "opcache.protect_memory=1" -d "zend.assertions=1" -d "zend.exception_ignore_args=0" -d "zend.exception_string_param_max_len=15" -d "short_open_tag=0" -d "extension_dir=/home/phpfuzz/WorkSpace/flowfusion/php-src/modules/" -d "zend_extension=/home/phpfuzz/WorkSpace/flowfusion/php-src/modules/opcache.so" -d "session.auto_start=0" -d "zlib.output_compression=Off" -d "opcache.record_warnings=1" -d "opcache.jit=1254" -d "fatal_error_backtraces=1" -d "max_execution_time=60" -d "opcache.enable=1" -d "opcache.enable_cli=1" ./test.php

Commit:

a28fb52719020ed737a869b5355892318cc13d29

Configurations:

CC="clang-12" CXX="clang++-12" CFLAGS="-DZEND_VERIFY_TYPE_INFERENCE" CXXFLAGS="-DZEND_VERIFY_TYPE_INFERENCE" ./configure --enable-debug --enable-address-sanitizer --enable-undefined-sanitizer --enable-re2c-cgoto --enable-fpm --enable-litespeed --enable-phpdbg-debug --enable-zts --enable-bcmath --enable-calendar --enable-dba --enable-dl-test --enable-exif --enable-ftp --enable-gd --enable-gd-jis-conv --enable-mbstring --enable-pcntl --enable-shmop --enable-soap --enable-sockets --enable-sysvmsg --enable-zend-test --with-zlib --with-bz2 --with-curl --with-enchant --with-gettext --with-gmp --with-mhash --with-ldap --with-libedit --with-readline --with-snmp --with-sodium --with-xsl --with-zip --with-mysqli --with-pdo-mysql --with-pdo-pgsql --with-pgsql --with-sqlite3 --with-pdo-sqlite --with-webp --with-jpeg --with-freetype --enable-sigchild --with-readline --with-pcre-jit --with-iconv

Operating System:

Ubuntu 20.04 Host, Docker 0599jiangyc/flowfusion:latest

This report is automatically generated by FlowFusion

PHP Version

a28fb52719020ed737a869b5355892318cc13d29

Operating System

No response

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First steps

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  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start with ext/opcache/jit/zend_jit_trace.c at zend_jit_trace_copy_ssa_var_range, line 1004, and reproduce the reported SEGV using the supplied PHP script and ASan/JIT configuration. Trace the failing SSA range handling and verify that the reproducer completes without an AddressSanitizer crash.

Written by the indexing model from the issue text.

Assessment

Tech stack
c, php
Domain
compilers
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
35/100

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