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@xxxxxxxxxx>
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@xxxxxxxxxxxxxxx> # 2.6.13
Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
---
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);
}
--
2.29.2
