Skip to content

Fix borked FETCH_W+ZEND_FETCH_GLOBAL_LOCK optimization #21121

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
iluuu1994 merged 2 commits into from
Feb 9, 2026
Merged

Fix borked FETCH_W+ZEND_FETCH_GLOBAL_LOCK optimization #21121

Show file tree
Hide file tree
Changes from 1 commit
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
154e8a8
Fix borked FETCH_W+ZEND_FETCH_GLOBAL_LOCK optimization
iluuu1994 Feb 3, 2026
1a3dd91
Apply suggestion from @arnaud-lb
iluuu1994 Feb 5, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
4 changes: 3 additions & 1 deletion Zend/Optimizer/block_pass.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -176,7 +176,9 @@ static void zend_optimize_block(zend_basic_block *block, zend_op_array *op_array
&& zend_optimizer_update_op1_const(op_array, opline, &c)) {
VAR_SOURCE(op1) = NULL;
if (opline->opcode != ZEND_JMP_NULL
&& !zend_bitset_in(used_ext, VAR_NUM(src->result.var))) {
&& !zend_bitset_in(used_ext, VAR_NUM(src->result.var))
/* FETCH_W with ZEND_FETCH_GLOBAL_LOCK does not free op1, which will be used again. */
&& (opline->opcode != ZEND_FETCH_W && (opline->extended_value & ZEND_FETCH_GLOBAL_LOCK))) {
Comment thread
iluuu1994 marked this conversation as resolved.
Outdated
literal_dtor(&ZEND_OP1_LITERAL(src));
MAKE_NOP(src);
}
Expand Down
27 changes: 27 additions & 0 deletions ext/opcache/tests/oss-fuzz-481014628.phpt
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,27 @@
--TEST--
OSS-Fuzz #481014628: Borked FETCH_W+ZEND_FETCH_GLOBAL_LOCK optimization
--EXTENSIONS--
opcache
--INI--
opcache.enable=1
opcache.enable_cli=1
--FILE--
<?php

function f() {
return 'foo';
}

function test() {
global ${f()};
var_dump($foo);
}

test();
$foo = 42;
test();

?>
--EXPECT--
NULL
int(42)
Loading