i2c: core: fix NULL-deref on adapter registration failure

If adapter registration ever fails the release callback would trigger a
NULL-pointer dereference as the completion struct has not been
initialised.

Note that before the offending commit this would instead have resulted
in a minor memory leak of the adapter name.

Fixes: 3f8c4f5e9a57 ("i2c: core: fix reference leak in i2c_register_adapter()")
Cc: stable@vger.kernel.org
Cc: Joe Hattori <joe@pf.is.s.u-tokyo.ac.jp>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index e42851a10098101532fd3e287a2ece0d4ff2b09d..fa9db415e21980b592bfb0b7e43ba0f8628bb229 100644 (file)
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -1574,8 +1574,7 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
        res = device_add(&adap->dev);
        if (res) {
                pr_err("adapter '%s': can't register device (%d)\n", adap->name, res);
-               put_device(&adap->dev);
-               goto err_remove_irq_domain;
+               goto err_put_adap;
        }
 
        adap->debugfs = debugfs_create_dir(dev_name(&adap->dev), i2c_debugfs_root);
@@ -1608,10 +1607,12 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
 out_reg:
        i2c_deregister_clients(adap);
        debugfs_remove_recursive(adap->debugfs);
+       device_del(&adap->dev);
+err_put_adap:
        init_completion(&adap->dev_released);
-       device_unregister(&adap->dev);
+       put_device(&adap->dev);
        wait_for_completion(&adap->dev_released);
-err_remove_irq_domain:
+
        i2c_host_notify_irq_teardown(adap);
 out_list:
        mutex_lock(&core_lock);