USB: fix omninet write vs. close race
omninet kills all URBs in close. However write() returns as soon as
the URB has been submitted. Killing the last URB means a race that
can lose that date written in the last call to write().
As a fix this is moved to shutdown().
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/serial/omninet.c b/drivers/usb/serial/omninet.c
index 357cc11..4adfab9 100644
--- a/drivers/usb/serial/omninet.c
+++ b/drivers/usb/serial/omninet.c
@@ -69,6 +69,7 @@
static int omninet_write (struct usb_serial_port *port, const unsigned char *buf, int count);
static int omninet_write_room (struct usb_serial_port *port);
static void omninet_shutdown (struct usb_serial *serial);
+static int omninet_attach (struct usb_serial *serial);
static struct usb_device_id id_table [] = {
{ USB_DEVICE(ZYXEL_VENDOR_ID, ZYXEL_OMNINET_ID) },
@@ -99,6 +100,7 @@
.num_bulk_in = 1,
.num_bulk_out = 2,
.num_ports = 1,
+ .attach = omninet_attach,
.open = omninet_open,
.close = omninet_close,
.write = omninet_write,
@@ -145,22 +147,30 @@
__u8 od_outseq; // Sequence number for bulk_out URBs
};
-static int omninet_open (struct usb_serial_port *port, struct file *filp)
+static int omninet_attach (struct usb_serial *serial)
{
- struct usb_serial *serial = port->serial;
- struct usb_serial_port *wport;
- struct omninet_data *od;
- int result = 0;
-
- dbg("%s - port %d", __FUNCTION__, port->number);
+ struct omninet_data *od;
+ struct usb_serial_port *port = serial->port[0];
od = kmalloc( sizeof(struct omninet_data), GFP_KERNEL );
if( !od ) {
err("%s- kmalloc(%Zd) failed.", __FUNCTION__, sizeof(struct omninet_data));
return -ENOMEM;
}
-
usb_set_serial_port_data(port, od);
+ return 0;
+}
+
+static int omninet_open (struct usb_serial_port *port, struct file *filp)
+{
+ struct usb_serial *serial = port->serial;
+ struct usb_serial_port *wport;
+ struct omninet_data *od = usb_get_serial_port_data(port);
+ int result = 0;
+
+ dbg("%s - port %d", __FUNCTION__, port->number);
+
+ od = kmalloc( sizeof(struct omninet_data), GFP_KERNEL );
wport = serial->port[1];
wport->tty = port->tty;
@@ -172,9 +182,6 @@
result = usb_submit_urb(port->read_urb, GFP_KERNEL);
if (result) {
err("%s - failed submitting read urb, error %d", __FUNCTION__, result);
- /* open failed - all allocations must be freed */
- kfree(od);
- usb_set_serial_port_data(port, NULL);
}
return result;
@@ -182,16 +189,8 @@
static void omninet_close (struct usb_serial_port *port, struct file * filp)
{
- struct usb_serial *serial = port->serial;
- struct usb_serial_port *wport;
-
dbg("%s - port %d", __FUNCTION__, port->number);
-
- wport = serial->port[1];
- usb_kill_urb(wport->write_urb);
usb_kill_urb(port->read_urb);
-
- kfree(usb_get_serial_port_data(port));
}
@@ -330,7 +329,12 @@
static void omninet_shutdown (struct usb_serial *serial)
{
+ struct usb_serial_port *wport = serial->port[1];
+ struct usb_serial_port *port = serial->port[0];
dbg ("%s", __FUNCTION__);
+
+ usb_kill_urb(wport->write_urb);
+ kfree(usb_get_serial_port_data(port));
}