USB: fix memory leak in cdc-acm

This fixes a memory leak on disconnect in cdc-acm

Thanks to 施金前 for finding it.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index fab23ee8702b..20104443081a 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -849,9 +849,10 @@ static void acm_write_buffers_free(struct acm *acm)
 {
         int i;
         struct acm_wb *wb;
+        struct usb_device *usb_dev = interface_to_usbdev(acm->control);
 
         for (wb = &acm->wb[0], i = 0; i < ACM_NW; i++, wb++) {
-                usb_buffer_free(acm->dev, acm->writesize, wb->buf, wb->dmah);
+                usb_buffer_free(usb_dev, acm->writesize, wb->buf, wb->dmah);
         }
 }