driver core: auxiliary bus: Fix memory leak when driver_register() fail

jira LE-3201
cve CVE-2021-47287
Rebuild_History Non-Buildable kernel-rt-4.18.0-553.22.1.rt7.363.el8_10
commit-author Peter Ujfalusi <[email protected]>
commit 4afa0c2

If driver_register() returns with error we need to free the memory
allocated for auxdrv->driver.name before returning from
__auxiliary_driver_register()

Fixes: 7de3697 ("Add auxiliary bus support")
	Reviewed-by: Dan Williams <[email protected]>
	Cc: stable <[email protected]>
	Signed-off-by: Peter Ujfalusi <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
	Signed-off-by: Greg Kroah-Hartman <[email protected]>
(cherry picked from commit 4afa0c2)
	Signed-off-by: Jonathan Maple <[email protected]>

Author: PlaidCat

drivers/base/auxiliary.c

@@ -231,6 +231,8 @@ EXPORT_SYMBOL_GPL(auxiliary_find_device);
 int __auxiliary_driver_register(struct auxiliary_driver *auxdrv,
 				struct module *owner, const char *modname)
 {
+	int ret;
+
 	if (WARN_ON(!auxdrv->probe) || WARN_ON(!auxdrv->id_table))
 		return -EINVAL;
 
@@ -246,7 +248,11 @@ int __auxiliary_driver_register(struct auxiliary_driver *auxdrv,
 	auxdrv->driver.bus = &auxiliary_bus_type;
 	auxdrv->driver.mod_name = modname;
 
-	return driver_register(&auxdrv->driver);
+	ret = driver_register(&auxdrv->driver);
+	if (ret)
+		kfree(auxdrv->driver.name);
+
+	return ret;
 }
 EXPORT_SYMBOL_GPL(__auxiliary_driver_register);