This is a note to let you know that I've just added the patch titled

USB: serial: iuu_phoenix: fix DMA from stack

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 54d0a3ab80f49f19ee916def62fe067596833403 Mon Sep 17 00:00:00 2001

From: Johan Hovold johan@kernel.org Date: Mon, 4 Jan 2021 15:50:07 +0100 Subject: USB: serial: iuu_phoenix: fix DMA from stack

Stack-allocated buffers cannot be used for DMA (on all architectures) so allocate the flush command buffer using kmalloc().

Fixes: 60a8fc017103 ("USB: add iuu_phoenix driver") Cc: stable stable@vger.kernel.org # 2.6.25 Reviewed-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Johan Hovold johan@kernel.org --- drivers/usb/serial/iuu_phoenix.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/drivers/usb/serial/iuu_phoenix.c b/drivers/usb/serial/iuu_phoenix.c index f1201d4de297..e8f06b41a503 100644 --- a/drivers/usb/serial/iuu_phoenix.c +++ b/drivers/usb/serial/iuu_phoenix.c @@ -532,23 +532,29 @@ static int iuu_uart_flush(struct usb_serial_port *port) struct device *dev = &port->dev; int i; int status; - u8 rxcmd = IUU_UART_RX; + u8 *rxcmd; struct iuu_private *priv = usb_get_serial_port_data(port);

if (iuu_led(port, 0xF000, 0, 0, 0xFF) < 0) return -EIO;

+ rxcmd = kmalloc(1, GFP_KERNEL); + if (!rxcmd) + return -ENOMEM; + + rxcmd[0] = IUU_UART_RX; + for (i = 0; i < 2; i++) { - status = bulk_immediate(port, &rxcmd, 1); + status = bulk_immediate(port, rxcmd, 1); if (status != IUU_OPERATION_OK) { dev_dbg(dev, "%s - uart_flush_write error\n", __func__); - return status; + goto out_free; }

status = read_immediate(port, &priv->len, 1); if (status != IUU_OPERATION_OK) { dev_dbg(dev, "%s - uart_flush_read error\n", __func__); - return status; + goto out_free; }

if (priv->len > 0) { @@ -556,12 +562,16 @@ static int iuu_uart_flush(struct usb_serial_port *port) status = read_immediate(port, priv->buf, priv->len); if (status != IUU_OPERATION_OK) { dev_dbg(dev, "%s - uart_flush_read error\n", __func__); - return status; + goto out_free; } } } dev_dbg(dev, "%s - uart_flush_read OK!\n", __func__); iuu_led(port, 0, 0xF000, 0, 0xFF); + +out_free: + kfree(rxcmd); + return status; }