From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:57616 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933098AbdCaPyU (ORCPT ); Fri, 31 Mar 2017 11:54:20 -0400 Subject: patch "tty/serial: atmel: fix race condition (TX+DMA)" added to tty-linus To: richard.genoud@gmail.com, gregkh@linuxfoundation.org, nicolas.ferre@microchip.com, stable@vger.kernel.org From: Date: Fri, 31 Mar 2017 17:53:56 +0200 Message-ID: <14909756368188@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled tty/serial: atmel: fix race condition (TX+DMA) to my tty git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git in the tty-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 31ca2c63fdc0aee725cbd4f207c1256f5deaabde Mon Sep 17 00:00:00 2001 From: Richard Genoud Date: Mon, 20 Mar 2017 11:52:41 +0100 Subject: tty/serial: atmel: fix race condition (TX+DMA) If uart_flush_buffer() is called between atmel_tx_dma() and atmel_complete_tx_dma(), the circular buffer has been cleared, but not atmel_port->tx_len. That leads to a circular buffer overflow (dumping (UART_XMIT_SIZE - atmel_port->tx_len) bytes). Tested-by: Nicolas Ferre Signed-off-by: Richard Genoud Cc: stable # 3.12+ Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/atmel_serial.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c index dcebb28ffbc4..5f644515ed33 100644 --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -1951,6 +1951,11 @@ static void atmel_flush_buffer(struct uart_port *port) atmel_uart_writel(port, ATMEL_PDC_TCR, 0); atmel_port->pdc_tx.ofs = 0; } + /* + * in uart_flush_buffer(), the xmit circular buffer has just + * been cleared, so we have to reset tx_len accordingly. + */ + atmel_port->tx_len = 0; } /* -- 2.12.1