| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.9 112/117] USB: serial: cyberjack: fix write-URB completion race | Date | Mon, 9 Nov 2020 13:55:38 +0100 |
| |
From: Johan Hovold <johan@kernel.org>
commit 985616f0457d9f555fff417d0da56174f70cc14f upstream.
The write-URB busy flag was being cleared before the completion handler was done with the URB, something which could lead to corrupt transfers due to a racing write request if the URB is resubmitted.
Fixes: 507ca9bc0476 ("[PATCH] USB: add ability for usb-serial drivers to determine if their write urb is currently being used.") Cc: stable <stable@vger.kernel.org> # 2.6.13 Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/usb/serial/cyberjack.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
--- a/drivers/usb/serial/cyberjack.c +++ b/drivers/usb/serial/cyberjack.c @@ -367,11 +367,12 @@ static void cyberjack_write_bulk_callbac struct cyberjack_private *priv = usb_get_serial_port_data(port); struct device *dev = &port->dev; int status = urb->status; + bool resubmitted = false; - set_bit(0, &port->write_urbs_free); if (status) { dev_dbg(dev, "%s - nonzero write bulk status received: %d\n", __func__, status); + set_bit(0, &port->write_urbs_free); return; } @@ -404,6 +405,8 @@ static void cyberjack_write_bulk_callbac goto exit; } + resubmitted = true; + dev_dbg(dev, "%s - priv->wrsent=%d\n", __func__, priv->wrsent); dev_dbg(dev, "%s - priv->wrfilled=%d\n", __func__, priv->wrfilled); @@ -420,6 +423,8 @@ static void cyberjack_write_bulk_callbac exit: spin_unlock(&priv->lock); + if (!resubmitted) + set_bit(0, &port->write_urbs_free); usb_serial_port_softint(port); }
|