USB: serial: fix port attribute-creation race

Fix attribute-creation race with userspace by using the port device
groups field to create the port attributes.

Also use %u when printing the port number, which is unsigned, even
though we do not currently support more than 128 ports per device.

Reported-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Greg Kroah-Hartman <greg@kroah.com>
This commit is contained in:
Johan Hovold 2015-02-18 10:34:52 +07:00
parent ca4383a394
commit 2deb96b5d4
2 changed files with 16 additions and 19 deletions

View File

@ -38,15 +38,6 @@ static int usb_serial_device_match(struct device *dev,
return 0;
}
static ssize_t port_number_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct usb_serial_port *port = to_usb_serial_port(dev);
return sprintf(buf, "%d\n", port->port_number);
}
static DEVICE_ATTR_RO(port_number);
static int usb_serial_device_probe(struct device *dev)
{
struct usb_serial_driver *driver;
@ -73,18 +64,10 @@ static int usb_serial_device_probe(struct device *dev)
goto exit_with_autopm;
}
retval = device_create_file(dev, &dev_attr_port_number);
if (retval) {
if (driver->port_remove)
driver->port_remove(port);
goto exit_with_autopm;
}
minor = port->minor;
tty_dev = tty_register_device(usb_serial_tty_driver, minor, dev);
if (IS_ERR(tty_dev)) {
retval = PTR_ERR(tty_dev);
device_remove_file(dev, &dev_attr_port_number);
if (driver->port_remove)
driver->port_remove(port);
goto exit_with_autopm;
@ -123,8 +106,6 @@ static int usb_serial_device_remove(struct device *dev)
minor = port->minor;
tty_unregister_device(usb_serial_tty_driver, minor);
device_remove_file(&port->dev, &dev_attr_port_number);
driver = port->serial->type;
if (driver->port_remove)
retval = driver->port_remove(port);

View File

@ -687,6 +687,21 @@ static void serial_port_dtr_rts(struct tty_port *port, int on)
drv->dtr_rts(p, on);
}
static ssize_t port_number_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct usb_serial_port *port = to_usb_serial_port(dev);
return sprintf(buf, "%u\n", port->port_number);
}
static DEVICE_ATTR_RO(port_number);
static struct attribute *usb_serial_port_attrs[] = {
&dev_attr_port_number.attr,
NULL
};
ATTRIBUTE_GROUPS(usb_serial_port);
static const struct tty_port_operations serial_port_ops = {
.carrier_raised = serial_port_carrier_raised,
.dtr_rts = serial_port_dtr_rts,
@ -902,6 +917,7 @@ static int usb_serial_probe(struct usb_interface *interface,
port->dev.driver = NULL;
port->dev.bus = &usb_serial_bus_type;
port->dev.release = &usb_serial_port_release;
port->dev.groups = usb_serial_port_groups;
device_initialize(&port->dev);
}