Assertion failure jit_CONST_FUNC_PROTO at ext/opcache/jit/zend_jit_ir.c

[YuanchengJiang]

Description

The following code:

<?php
try {
$e = enum_exists('UnitEnum') ? UnitEnum::cases() : [];
} catch (\Throwable $_ffl_e) {}

Resulted in this output:

php: ext/opcache/jit/zend_jit_ir.c:554: ir_ref jit_CONST_FUNC_PROTO(zend_jit_ctx *, uintptr_t, ir_ref): Assertion `addr != 0' failed.
Aborted (core dumped)

To reproduce:

/home/fuzz/WorkSpace/fusion-fuzz/projects/php/php-src/sapi/cli/php  -d opcache.enable_cli=1 -d opcache.jit=1205 ./test.php

Commit:

51911cc1c64e7435b19c45685032e094b838183b

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 bug was found by fusion-fuzz

PHP Version

nightly

Operating System

No response

[CodedByManish]

Seems like a JIT crash while resolving enum methods.

The assertion addr != 0 in jit_CONST_FUNC_PROTO points to a null/invalid address during IR generation, likely when handling UnitEnum::cases() after enum_exists().

Reproduces only with JIT enabled (opcache.jit=1205), so it feels like an OPcache JIT + enum reflection edge case rather than userland issue.

Probably worth checking how enum method calls are resolved/optimized in JIT before IR build.

[devnexen]

trying to get familiar a bit more with the engine, that change fixes it for me

diff --git a/Zend/Optimizer/zend_optimizer.c b/Zend/Optimizer/zend_optimizer.c
index 245c67c4544..d88bd0ab55c 100644
--- a/Zend/Optimizer/zend_optimizer.c
+++ b/Zend/Optimizer/zend_optimizer.c
@@ -943,7 +943,7 @@ zend_function *zend_optimizer_get_called_func(
                                if (ce) {
                                        zend_string *func_name = Z_STR_P(CRT_CONSTANT(opline->op2) + 1);
                                        zend_function *fbc = zend_hash_find_ptr(&ce->function_table, func_name);
-                                       if (fbc) {
+                                       if (fbc && !(fbc->common.fn_flags & ZEND_ACC_ABSTRACT)) {
                                                bool is_public = (fbc->common.fn_flags & ZEND_ACC_PUBLIC) != 0;
                                                bool same_scope = fbc->common.scope == op_array->scope;
                                                if (is_public || same_scope) {

do not know if, instead, the fix should be on the JIT itself, @arnaud-lb @iluuu1994 thoughts ?

[arnaud-lb]

These changes makes sense as a ZEND_INIT_STATIC_METHOD_CALL to an abstract method can never result in a function call. One alternative would be to set *is_prototype.