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Commit 070c0b17 authored by Alexey Khoroshilov's avatar Alexey Khoroshilov Committed by Greg Kroah-Hartman
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USB: cdc-acm: fix double usb_autopm_put_interface() in acm_port_activate() 



If acm_submit_read_urbs() fails in acm_port_activate(), error handling
code calls usb_autopm_put_interface() while it is already called
before acm_submit_read_urbs(). The patch reorganizes error handling code
to avoid double decrement of USB interface's PM-usage counter.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: default avatarAlexey Khoroshilov <khoroshilov@ispras.ru>
Acked-by: default avatarOliver Neukum <oliver@neukum.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent f9076e28

drivers/usb/class/cdc-acm.c

+4 −2
Original line number Diff line number Diff line
@@ -518,13 +518,16 @@ 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))

	    (acm->ctrl_caps & USB_CDC_CAP_LINE)) {

		usb_autopm_put_interface(acm->control);

		goto error_set_control;

	}



	usb_autopm_put_interface(acm->control);
@@ -549,7 +552,6 @@ error_submit_read_urbs: 
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);