This is a note to let you know that I've just added the patch titled
USB: serial: cyberjack: fix write-URB completion race
to my usb git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git in the usb-linus branch.
The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.
If you have any questions about this process, please let me know.
From 985616f0457d9f555fff417d0da56174f70cc14f Mon Sep 17 00:00:00 2001
From: Johan Hovold johan@kernel.org Date: Mon, 26 Oct 2020 09:25:48 +0100 Subject: USB: serial: cyberjack: fix write-URB completion race
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 --- drivers/usb/serial/cyberjack.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/serial/cyberjack.c b/drivers/usb/serial/cyberjack.c index 821970609695..2e40908963da 100644 --- a/drivers/usb/serial/cyberjack.c +++ b/drivers/usb/serial/cyberjack.c @@ -357,11 +357,12 @@ static void cyberjack_write_bulk_callback(struct urb *urb) struct device *dev = &port->dev; int status = urb->status; unsigned long flags; + 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; }
@@ -394,6 +395,8 @@ static void cyberjack_write_bulk_callback(struct urb *urb) 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);
@@ -410,6 +413,8 @@ static void cyberjack_write_bulk_callback(struct urb *urb)
exit: spin_unlock_irqrestore(&priv->lock, flags); + if (!resubmitted) + set_bit(0, &port->write_urbs_free); usb_serial_port_softint(port); }