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Fix GH-21006: JIT SEGV with FETCH_OBJ_FUNC_ARG and property hooks #21369

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Fix GH-21006: JIT SEGV with FETCH_OBJ_FUNC_ARG and property hooks #21369

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21 changes: 21 additions & 0 deletions ext/opcache/jit/zend_jit_ir.c
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Original file line number Diff line number Diff line change
Expand Up @@ -17091,6 +17091,27 @@ static int zend_jit_trace_handler(zend_jit_ctx *jit, const zend_op_array *op_arr
ir_ref ref;

zend_jit_set_ip(jit, opline);
/* FETCH_OBJ_FUNC_ARG/FETCH_OBJ_R may dispatch to a VM handler that
* pushes a call frame for SIMPLE_GET property hooks, which would
* corrupt the trace's call stack. Clear the SIMPLE_GET flag so the
* handler falls through to read_property instead. */
if ((opline->opcode == ZEND_FETCH_OBJ_FUNC_ARG || opline->opcode == ZEND_FETCH_OBJ_R)
&& opline->op2_type == IS_CONST) {
ir_ref run_time_cache = ir_LOAD_A(jit_EX(run_time_cache));
ir_ref cache_slot_ref = ir_ADD_OFFSET(run_time_cache,
(opline->extended_value & ~ZEND_FETCH_OBJ_FLAGS) + sizeof(void*));
ir_ref prop_offset_ref = ir_LOAD_A(cache_slot_ref);
/* Only clear SIMPLE_GET for hooked property offsets (range 1..15).
* Other offset types (dynamic = -1, valid >= 16) may have bit 3
* set coincidentally and must not be modified. */
ir_ref if_hooked_lo = ir_IF(ir_GE(prop_offset_ref, ir_CONST_ADDR(ZEND_PROPERTY_HOOK_SIMPLE_GET_BIT)));
ir_IF_TRUE(if_hooked_lo);
ir_ref if_hooked_hi = ir_IF(ir_LT(prop_offset_ref, ir_CONST_ADDR(ZEND_FIRST_PROPERTY_OFFSET)));
ir_IF_TRUE(if_hooked_hi);
ir_STORE(cache_slot_ref, ir_AND_A(prop_offset_ref, ir_CONST_ADDR(~(uintptr_t)ZEND_PROPERTY_HOOK_SIMPLE_GET_BIT)));
ir_MERGE_WITH_EMPTY_FALSE(if_hooked_hi);
ir_MERGE_WITH_EMPTY_FALSE(if_hooked_lo);
}
if (GCC_GLOBAL_REGS) {
ir_CALL(IR_VOID, ir_CONST_FUNC(handler));
} else {
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59 changes: 59 additions & 0 deletions ext/opcache/tests/jit/gh21006.phpt
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Original file line number Diff line number Diff line change
@@ -0,0 +1,59 @@
--TEST--
GH-21006: JIT SEGV with FETCH_OBJ_FUNC_ARG and property hooks
--INI--
opcache.enable=1
opcache.enable_cli=1
opcache.jit=tracing
opcache.jit_hot_loop=61
opcache.jit_hot_func=127
opcache.jit_hot_return=8
opcache.jit_hot_side_exit=8
--FILE--
<?php
namespace Test;

class C
{
public $prop {
get => 'sha256';
}

public function sign()
{
return hash_hmac(
algo: $this->prop,
data: '',
key: '',
);
}
}

$obj = new C();
for ($i = 0; $i < 100; $i++) {
$obj->sign();
}

// Dynamic property access through FETCH_OBJ_FUNC_ARG must not corrupt
// the ZEND_DYNAMIC_PROPERTY_OFFSET sentinel in the runtime cache.
#[\AllowDynamicProperties]
class D
{
public function test()
{
return hash_hmac(
algo: $this->algo,
data: '',
key: '',
);
}
}

$d = new D();
$d->algo = 'sha256';
for ($i = 0; $i < 100; $i++) {
$d->test();
}
echo "OK\n";
?>
--EXPECT--
OK
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