usb: cdc_acm: Do not leak URB buffers

When the ACM TTY port is disconnected, the URBs it uses must be killed, and
then the buffers must be freed. Unfortunately a previous refactor removed
the code freeing the buffers because it looked extremely similar to the
code killing the URBs.

As a result, there were many new leaks for each plug/unplug cycle of a
CDC-ACM device, that were detected by kmemleak.

Restore the missing code, and the memory leak is removed.

Fixes: ba8c931ded ("cdc-acm: refactor killing urbs")
Signed-off-by: Romain Izard <romain.izard.pro@gmail.com>
Acked-by: Oliver Neukum <oneukum@suse.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Romain Izard 2018-09-20 16:49:04 +02:00 committed by Greg Kroah-Hartman
parent dcb44ac060
commit f2924d4b16

View File

@ -1514,6 +1514,7 @@ static void acm_disconnect(struct usb_interface *intf)
{
struct acm *acm = usb_get_intfdata(intf);
struct tty_struct *tty;
int i;
/* sibling interface is already cleaning up */
if (!acm)
@ -1544,6 +1545,11 @@ static void acm_disconnect(struct usb_interface *intf)
tty_unregister_device(acm_tty_driver, acm->minor);
usb_free_urb(acm->ctrlurb);
for (i = 0; i < ACM_NW; i++)
usb_free_urb(acm->wb[i].urb);
for (i = 0; i < acm->rx_buflimit; i++)
usb_free_urb(acm->read_urbs[i]);
acm_write_buffers_free(acm);
usb_free_coherent(acm->dev, acm->ctrlsize, acm->ctrl_buffer, acm->ctrl_dma);
acm_read_buffers_free(acm);