USB: serial: digi_acceleport: fix hard lockup on disconnect

If submitting the OOB write urb fails persistently (e.g if the device is
being disconnected) the driver would loop indefinitely with interrupts
disabled.

Check for urb submission errors when sending OOB commands to avoid
hanging if, for example, open(), set_termios() or close() races with a
physical disconnect.

This is issue was flagged by Sashiko when reviewing an unrelated change
to the driver.

Link: https://sashiko.dev/#/patchset/20260610132232.356139-1-johan%40kernel.org?part=1
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>

diff --git a/drivers/usb/serial/digi_acceleport.c b/drivers/usb/serial/digi_acceleport.c
index 5f3a9568217900cceee2f2c0029e40f8cd4609ee..fa5c3539f806e2fdf7c82e3f1b438a36f07e342e 100644 (file)
--- a/drivers/usb/serial/digi_acceleport.c
+++ b/drivers/usb/serial/digi_acceleport.c
@@ -392,12 +392,14 @@ static int digi_write_oob_command(struct usb_serial_port *port,
                        len &= ~3;
                memcpy(oob_port->write_urb->transfer_buffer, buf, len);
                oob_port->write_urb->transfer_buffer_length = len;
+
                ret = usb_submit_urb(oob_port->write_urb, GFP_ATOMIC);
-               if (ret == 0) {
-                       oob_priv->dp_write_urb_in_use = 1;
-                       count -= len;
-                       buf += len;
-               }
+               if (ret)
+                       break;
+
+               oob_priv->dp_write_urb_in_use = 1;
+               count -= len;
+               buf += len;
        }
        spin_unlock_irqrestore(&oob_priv->dp_port_lock, flags);
        if (ret)