Fix #79825: opcache.file_cache causes SIGSEGV with custom opcode hand…

…lers

Modules may have changed after restart which can cause dangling pointers from custom opcode handlers in the second-level cache files. This fix includes the installed module names and versions in the accel_system_id hash as entropy. Closes GH-5836

NEWS

@@ -18,6 +18,8 @@ PHP                                                                        NEWS
 - OPcache:
   . Fixed bug #80002 (calc free space for new interned string is wrong).
     (t-matsuno)
+  . Fixed bug #79825 (opcache.file_cache causes SIGSEGV when custom opcode
+    handlers changed). (SammyK)
 
 - PDO:
   . Fixed bug #80027 (Terrible performance using $query->fetch on queries with

ext/opcache/ZendAccelerator.c

@@ -2692,6 +2692,9 @@ static void accel_gen_system_id(void)
 	unsigned char digest[16], c;
 	char *md5str = ZCG(system_id);
 	int i;
+	zend_module_entry *module;
+	zend_extension *extension;
+	zend_llist_position pos;
 
 	PHP_MD5Init(&context);
 	PHP_MD5Update(&context, PHP_VERSION, sizeof(PHP_VERSION)-1);
@@ -2702,6 +2705,19 @@ static void accel_gen_system_id(void)
 		PHP_MD5Update(&context, __DATE__, sizeof(__DATE__)-1);
 		PHP_MD5Update(&context, __TIME__, sizeof(__TIME__)-1);
 	}
+	/* Modules may have changed after restart which can cause dangling pointers from
+     * custom opcode handlers in the second-level cache files
+     */
+	ZEND_HASH_FOREACH_PTR(&module_registry, module) {
+		PHP_MD5Update(&context, module->name, strlen(module->name));
+		PHP_MD5Update(&context, module->version, strlen(module->version));
+	} ZEND_HASH_FOREACH_END();
+	extension = (zend_extension *) zend_llist_get_first_ex(&zend_extensions, &pos);
+	while (extension) {
+		PHP_MD5Update(&context, extension->name, strlen(extension->name));
+		PHP_MD5Update(&context, extension->version, strlen(extension->version));
+		extension = (zend_extension *) zend_llist_get_next_ex(&zend_extensions, &pos);
+	}
 	PHP_MD5Final(digest, &context);
 	for (i = 0; i < 16; i++) {
 		c = digest[i] >> 4;