From: Qiu-ji Chen Date: Thu, 7 Nov 2024 11:35:34 +0000 (+0800) Subject: USB: serial: ftdi_sio: Fix atomicity violation in get_serial_info() X-Git-Tag: v6.13-rc1~31^2~10^2 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=8b524944f92ccad925b574f645e9c2709cf60d1e;p=thirdparty%2Flinux.git USB: serial: ftdi_sio: Fix atomicity violation in get_serial_info() Our static checker found a bug where set_serial_info() uses a mutex, but get_serial_info() does not. Fortunately, the impact of this is relatively minor. It doesn't cause a crash or any other serious issues. However, if a race condition occurs between set_serial_info() and get_serial_info(), there is a chance that the data returned by get_serial_info() will be inconsistent. Fixes: 3ae36bed3a93 ("fdti_sio: switch to ->[sg]et_serial()") Signed-off-by: Qiu-ji Chen Signed-off-by: Johan Hovold --- diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c index c6f17d732b958..e07c5e3eb18c0 100644 --- a/drivers/usb/serial/ftdi_sio.c +++ b/drivers/usb/serial/ftdi_sio.c @@ -1443,9 +1443,11 @@ static void get_serial_info(struct tty_struct *tty, struct serial_struct *ss) struct usb_serial_port *port = tty->driver_data; struct ftdi_private *priv = usb_get_serial_port_data(port); + mutex_lock(&priv->cfg_lock); ss->flags = priv->flags; ss->baud_base = priv->baud_base; ss->custom_divisor = priv->custom_divisor; + mutex_unlock(&priv->cfg_lock); } static int set_serial_info(struct tty_struct *tty, struct serial_struct *ss)