Commit 7e7797e7f6f7bfab73fca02c65e40eaa5bb9000c

Authored by Johan Hovold
Committed by Greg Kroah-Hartman
1 parent 15e5bee33f

USB: cdc-acm: fix potential null-pointer dereference on disconnect

Fix potential null-pointer exception on disconnect introduced by commit
11ea859d64b69a747d6b060b9ed1520eab1161fe (USB: additional power savings
for cdc-acm devices that support remote wakeup).

Only access acm->dev after making sure it is non-null in control urb
completion handler.

Cc: stable <stable@kernel.org>
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Showing 1 changed file with 2 additions and 1 deletions Side-by-side Diff

drivers/usb/class/cdc-acm.c
... ... @@ -297,6 +297,8 @@
297 297 if (!ACM_READY(acm))
298 298 goto exit;
299 299  
  300 + usb_mark_last_busy(acm->dev);
  301 +
300 302 data = (unsigned char *)(dr + 1);
301 303 switch (dr->bNotificationType) {
302 304 case USB_CDC_NOTIFY_NETWORK_CONNECTION:
... ... @@ -336,7 +338,6 @@
336 338 break;
337 339 }
338 340 exit:
339   - usb_mark_last_busy(acm->dev);
340 341 retval = usb_submit_urb(urb, GFP_ATOMIC);
341 342 if (retval)
342 343 dev_err(&urb->dev->dev, "%s - usb_submit_urb failed with "