USB: serial: keyspan_pda: verify endpoints at probe

commit 5d9b0f859babe96175cd33d7162a9463a875ffde upstream.

Check for the expected endpoints in attach() and fail loudly if not
present.

Note that failing to do this appears to be benign since da280e348866
("USB: keyspan_pda: clean up write-urb busy handling") which prevents a
NULL-pointer dereference in write() by never marking a non-existent
write-urb as free.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>

diff --git a/drivers/usb/serial/keyspan_pda.c b/drivers/usb/serial/keyspan_pda.c
index 5f1d382e55cfbd3b673c4b26dbf7863fbf0d4be2..05c567bf5cfa5e16c51db9ddfcbd2521ab6dc0f6 100644 (file)
--- a/drivers/usb/serial/keyspan_pda.c
+++ b/drivers/usb/serial/keyspan_pda.c
@@ -697,6 +697,19 @@ MODULE_FIRMWARE("keyspan_pda/keyspan_pda.fw");
 MODULE_FIRMWARE("keyspan_pda/xircom_pgs.fw");
 #endif
 
+static int keyspan_pda_attach(struct usb_serial *serial)
+{
+       unsigned char num_ports = serial->num_ports;
+
+       if (serial->num_bulk_out < num_ports ||
+                       serial->num_interrupt_in < num_ports) {
+               dev_err(&serial->interface->dev, "missing endpoints\n");
+               return -ENODEV;
+       }
+
+       return 0;
+}
+
 static int keyspan_pda_port_probe(struct usb_serial_port *port)
 {
 
@@ -774,6 +787,7 @@ static struct usb_serial_driver keyspan_pda_device = {
        .break_ctl =            keyspan_pda_break_ctl,
        .tiocmget =             keyspan_pda_tiocmget,
        .tiocmset =             keyspan_pda_tiocmset,
+       .attach =               keyspan_pda_attach,
        .port_probe =           keyspan_pda_port_probe,
        .port_remove =          keyspan_pda_port_remove,
 };