Under certain circumstances uart_dtr_rts might cause an oops. It dies
because port->tty is NULL. To fix this, let's take a reference of
port->tty by tty_port_tty_get. And if it is not there already, fail
gracefully.
After all, indeed drop the reference.
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
Cc: Greg KH <gregkh@xxxxxxx>
Cc: Alan Cox <alan@xxxxxxxxxxxxxxxxxxx>
---
drivers/tty/serial/serial_core.c | 8 ++++++--
1 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index d6e7240..88a0472 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -1531,8 +1531,12 @@ static void uart_dtr_rts(struct tty_port *port, int onoff)
* If this is the first open to succeed,
* adjust things to suit.
*/
- if (!test_and_set_bit(ASYNCB_NORMAL_ACTIVE, &port->flags))
- uart_update_termios(port->tty, state);
+ if (!test_and_set_bit(ASYNCB_NORMAL_ACTIVE, &port->flags)) {
+ struct tty_struct *tty = tty_port_tty_get(port);
+ if (tty)
+ uart_update_termios(tty, state);
+ tty_kref_put(tty);
+ }
}
else
uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
--
1.7.4.1
--
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