USB: legousbtower: fix open after failed reset request

BugLink: https://bugs.launchpad.net/bugs/1848750
commit 0b074f6986751361ff442bc1127c1648567aa8d6 upstream.

The driver would return with a nonzero open count in case the reset
control request failed. This would prevent any further attempts to open
the char dev until the device was disconnected.

Fix this by incrementing the open count only on successful open.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Johan Hovold <johan@kernel.org>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20190919083039.30898-5-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/drivers/usb/misc/legousbtower.c b/drivers/usb/misc/legousbtower.c
index 4fa9998826359332a2f370b184b94430dfa45c79..44d6a3381804b9cf1d6ace315af01475e7aae0da 100644 (file)
--- a/drivers/usb/misc/legousbtower.c
+++ b/drivers/usb/misc/legousbtower.c
@@ -348,7 +348,6 @@ static int tower_open (struct inode *inode, struct file *file)
                retval = -EBUSY;
                goto unlock_exit;
        }
-       dev->open_count = 1;
 
        /* reset the tower */
        result = usb_control_msg (dev->udev,
@@ -388,13 +387,14 @@ static int tower_open (struct inode *inode, struct file *file)
                dev_err(&dev->udev->dev,
                        "Couldn't submit interrupt_in_urb %d\n", retval);
                dev->interrupt_in_running = 0;
-               dev->open_count = 0;
                goto unlock_exit;
        }
 
        /* save device in the file's private structure */
        file->private_data = dev;
 
+       dev->open_count = 1;
+
 unlock_exit:
        mutex_unlock(&dev->lock);