tty/serial: atmel: fix race condition (TX+DMA)
authorRichard Genoud <richard.genoud@gmail.com>
Mon, 20 Mar 2017 10:52:41 +0000 (11:52 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 31 Mar 2017 15:26:19 +0000 (17:26 +0200)
commit31ca2c63fdc0aee725cbd4f207c1256f5deaabde
tree56d7a7b2697c1c90a988dffb36539f452006763c
parenta6040bc610554c66088fda3608ae5d6307c548e4
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 <nicolas.ferre@microchip.com>
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Cc: stable <stable@vger.kernel.org> # 3.12+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/tty/serial/atmel_serial.c