hwmon: (nzxt-smart2) Check return value of init_device() in probe

The init_device() call in nzxt_smart2_hid_probe() can fail because it
sends HID output reports to the hardware to detect fans and set the
update interval.  If the hardware is not responding or the HID reports
fail, init_device() returns a negative error code.

However, the return value was ignored, causing the probe to continue
and register an hwmon device even though the device was never properly
initialized.  This leads to an inconsistent state where the driver
reports stale data or blocks on wait queues that will never be woken.

The same function's return value is already checked in the
reset_resume() handler, confirming the author's intent that errors
should be propagated.

Note that this fix was not possible before commit 59d104b54b0b
("hwmon: (nzxt-smart2) Stop device IO before calling hid_hw_stop")
because the out_hw_close error path was missing hid_device_io_stop(),
which would have opened a use-after-free risk window.

Fixes: 53e68c20aeb1 ("hwmon: add driver for NZXT RGB&Fan Controller/Smart Device v2.")
Signed-off-by: Qingshuang Fu <fuqingshuang@kylinos.cn>
Link: https://lore.kernel.org/r/20260804074842.505923-1-fffsqian@163.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/drivers/hwmon/nzxt-smart2.c b/drivers/hwmon/nzxt-smart2.c
index ff0c0bee0e8397387079eac1e07ef4f2dabaf5b7..efc78a8f58c88c6e7aaa373be3451fe2a80a0146 100644 (file)
--- a/drivers/hwmon/nzxt-smart2.c
+++ b/drivers/hwmon/nzxt-smart2.c
@@ -754,7 +754,11 @@ static int nzxt_smart2_hid_probe(struct hid_device *hdev,
 
        hid_device_io_start(hdev);
 
-       init_device(drvdata, UPDATE_INTERVAL_DEFAULT_MS);
+       ret = init_device(drvdata, UPDATE_INTERVAL_DEFAULT_MS);
+       if (ret) {
+               dev_err(&hdev->dev, "init_device failed: %d\n", ret);
+               goto out_hw_close;
+       }
 
        drvdata->hwmon =
                hwmon_device_register_with_info(&hdev->dev, "nzxtsmart2", drvdata,