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| author | Johan Hovold <johan@kernel.org> | 2017-11-03 15:30:55 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-11-28 16:00:50 +0100 |
| commit | 8bcd4e6a8decac251d55c4377e2e67f052777ce0 (patch) | |
| tree | e9ecd5cb20a5a37a2f255d8d51622be7eec2b5de | |
| parent | fd00cf81a9a84776ba58e56bd042c726dcf75cf3 (diff) | |
| download | linux-8bcd4e6a8decac251d55c4377e2e67f052777ce0.tar.bz2 | |
serdev: ttyport: fix NULL-deref on hangup
Make sure to use a properly refcounted tty_struct in write_wake up to
avoid dereferencing a NULL-pointer when a port is being hung up.
Fixes: bed35c6dfa6a ("serdev: add a tty port controller driver")
Cc: stable <stable@vger.kernel.org> # 4.11
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/tty/serdev/serdev-ttyport.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/drivers/tty/serdev/serdev-ttyport.c b/drivers/tty/serdev/serdev-ttyport.c index 09fbdd52a561..12cb9139073e 100644 --- a/drivers/tty/serdev/serdev-ttyport.c +++ b/drivers/tty/serdev/serdev-ttyport.c @@ -49,12 +49,19 @@ static void ttyport_write_wakeup(struct tty_port *port) { struct serdev_controller *ctrl = port->client_data; struct serport *serport = serdev_controller_get_drvdata(ctrl); + struct tty_struct *tty; + + tty = tty_port_tty_get(port); + if (!tty) + return; - if (test_and_clear_bit(TTY_DO_WRITE_WAKEUP, &port->tty->flags) && + if (test_and_clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags) && test_bit(SERPORT_ACTIVE, &serport->flags)) serdev_controller_write_wakeup(ctrl); - wake_up_interruptible_poll(&port->tty->write_wait, POLLOUT); + wake_up_interruptible_poll(&tty->write_wait, POLLOUT); + + tty_kref_put(tty); } static const struct tty_port_client_operations client_ops = { |