4.14-stable review patch. If anyone has any objections, please let me know.
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From: Stefan Agner stefan@agner.ch
commit 3216c622a24b0ebb9c159a8d1daf7f17a106b3f5 upstream.
The function tty_port_tty_get() gets a reference to the tty. Since the code is not using tty_port_tty_set(), the reference is kept even after closing the tty.
Avoid using tty_port_tty_get() by directly access the tty instance. Since lpuart_start_rx_dma() is called from the .startup() and .set_termios() callback, it is safe to assume the tty instance is valid.
Cc: stable@vger.kernel.org # v4.9+ Fixes: 5887ad43ee02 ("tty: serial: fsl_lpuart: Use cyclic DMA for Rx") Signed-off-by: Stefan Agner stefan@agner.ch Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/tty/serial/fsl_lpuart.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -983,7 +983,8 @@ static inline int lpuart_start_rx_dma(st struct circ_buf *ring = &sport->rx_ring; int ret, nent; int bits, baud; - struct tty_struct *tty = tty_port_tty_get(&sport->port.state->port); + struct tty_port *port = &sport->port.state->port; + struct tty_struct *tty = port->tty; struct ktermios *termios = &tty->termios;
baud = tty_get_baud_rate(tty);