USB: c67x00: fix use after free in c67x00_giveback_urb
commit
211f08347355cba1f769bbf3355816a12b3ddd55 upstream.
clang static analysis flags this error
c67x00-sched.c:489:55: warning: Use of memory after it is freed [unix.Malloc]
usb_hcd_giveback_urb(c67x00_hcd_to_hcd(c67x00), urb, urbp->status);
^~~~~~~~~~~~
Problem happens in this block of code
c67x00_release_urb(c67x00, urb);
usb_hcd_unlink_urb_from_ep(c67x00_hcd_to_hcd(c67x00), urb);
spin_unlock(&c67x00->lock);
usb_hcd_giveback_urb(c67x00_hcd_to_hcd(c67x00), urb, urbp->status);
In the call to c67x00_release_urb has this freeing of urbp
urbp = urb->hcpriv;
urb->hcpriv = NULL;
list_del(&urbp->hep_node);
kfree(urbp);
And so urbp is freed before usb_hcd_giveback_urb uses it as its 3rd
parameter.
Since all is required is the status, pass the status directly as is
done in c64x00_urb_dequeue
Fixes:
e9b29ffc519b ("USB: add Cypress c67x00 OTG controller HCD driver")
Signed-off-by: Tom Rix <trix@redhat.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200708131243.24336-1-trix@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>