media: rc: ensure that uevent can be read directly after rc device register

There is a race condition where if the /sys/class/rc0/uevent file is read
before rc_dev->registered is set to true, -ENODEV will be returned.

Link: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1901089
Cc: stable@vger.kernel.org
Fixes: a2e2d73fa281 ("media: rc: do not access device via sysfs after rc_unregister_device()")
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

diff --git a/drivers/media/rc/rc-main.c b/drivers/media/rc/rc-main.c
index 1d811e5..29d4d01 100644 (file)
--- a/drivers/media/rc/rc-main.c
+++ b/drivers/media/rc/rc-main.c
@@ -1928,6 +1928,8 @@ int rc_register_device(struct rc_dev *dev)
                        goto out_raw;
        }
 
+       dev->registered = true;
+
        rc = device_add(&dev->dev);
        if (rc)
                goto out_rx_free;
@@ -1937,8 +1939,6 @@ int rc_register_device(struct rc_dev *dev)
                 dev->device_name ?: "Unspecified device", path ?: "N/A");
        kfree(path);
 
-       dev->registered = true;
-
        /*
         * once the the input device is registered in rc_setup_rx_device,
         * userspace can open the input device and rc_open() will be called