From dad20581913fcbe8bea59f8227f5f8df255263f6 Mon Sep 17 00:00:00 2001
From: Niels Dossche <7771979+nielsdos@users.noreply.github.com>
Date: Mon, 17 Jul 2023 02:44:35 +0200
Subject: [PATCH] Prevent potential deadlock if accelerated globals cannot be
 allocated

Not sure if this is possible to hit in practice, zend_accel_error_noreturn
doesn't return so the unlock isn't called. Other callsites that use both
zend_accel_error_noreturn and zend_shared_alloc_unlock first perform the
unlocking.
---
 ext/opcache/ZendAccelerator.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/ext/opcache/ZendAccelerator.c b/ext/opcache/ZendAccelerator.c
index ed0602394ce97..f0dd678c46403 100644
--- a/ext/opcache/ZendAccelerator.c
+++ b/ext/opcache/ZendAccelerator.c
@@ -2863,8 +2863,8 @@ static int zend_accel_init_shm(void)
 		accel_shared_globals = zend_shared_alloc(sizeof(zend_accel_shared_globals) + sizeof(uint32_t));
 	}
 	if (!accel_shared_globals) {
-		zend_accel_error_noreturn(ACCEL_LOG_FATAL, "Insufficient shared memory!");
 		zend_shared_alloc_unlock();
+		zend_accel_error_noreturn(ACCEL_LOG_FATAL, "Insufficient shared memory!");
 		return FAILURE;
 	}
 	memset(accel_shared_globals, 0, sizeof(zend_accel_shared_globals));