USB: cdc-acm: fix open and suspend race

We must not do the usb_autopm_put_interface() before submitting the read
urbs or we might end up doing I/O to a suspended device.

Fixes: 088c64f812 ("USB: cdc-acm: re-write read processing")
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Johan Hovold 2014-05-26 19:23:42 +02:00 committed by Greg Kroah-Hartman
parent 183a45087d
commit 703df3297f

View file

@ -528,19 +528,15 @@ static int acm_port_activate(struct tty_port *port, struct tty_struct *tty)
if (usb_submit_urb(acm->ctrlurb, GFP_KERNEL)) {
dev_err(&acm->control->dev,
"%s - usb_submit_urb(ctrl irq) failed\n", __func__);
usb_autopm_put_interface(acm->control);
goto error_submit_urb;
}
acm->ctrlout = ACM_CTRL_DTR | ACM_CTRL_RTS;
if (acm_set_control(acm, acm->ctrlout) < 0 &&
(acm->ctrl_caps & USB_CDC_CAP_LINE)) {
usb_autopm_put_interface(acm->control);
goto error_set_control;
}
usb_autopm_put_interface(acm->control);
/*
* Unthrottle device in case the TTY was closed while throttled.
*/
@ -552,6 +548,8 @@ static int acm_port_activate(struct tty_port *port, struct tty_struct *tty)
if (acm_submit_read_urbs(acm, GFP_KERNEL))
goto error_submit_read_urbs;
usb_autopm_put_interface(acm->control);
mutex_unlock(&acm->mutex);
return 0;
@ -562,6 +560,7 @@ static int acm_port_activate(struct tty_port *port, struct tty_struct *tty)
error_set_control:
usb_kill_urb(acm->ctrlurb);
error_submit_urb:
usb_autopm_put_interface(acm->control);
error_get_interface:
disconnected:
mutex_unlock(&acm->mutex);