[src/trunk]: src/sys/dev/usb Avoid use after free when closing interrupt pipe...

[skrll <skrll%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/eedd7537e737
branches:  trunk
changeset: 447430:eedd7537e737
user:      skrll <skrll%NetBSD.org@localhost>
date:      Thu Jan 10 22:13:07 2019 +0000

description:
Avoid use after free when closing interrupt pipe transfer by calling
upm_close before destroying the interupt pipe xfer.

Found by kasan on wiz's machine.

diffstat:

 sys/dev/usb/usbdi.c |  7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)

diffs (34 lines):

diff -r c1b4171b3d4e -r eedd7537e737 sys/dev/usb/usbdi.c
--- a/sys/dev/usb/usbdi.c       Thu Jan 10 22:02:16 2019 +0000
+++ b/sys/dev/usb/usbdi.c       Thu Jan 10 22:13:07 2019 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: usbdi.c,v 1.180 2018/11/16 00:34:50 manu Exp $ */
+/*     $NetBSD: usbdi.c,v 1.181 2019/01/10 22:13:07 skrll Exp $        */
 
 /*
  * Copyright (c) 1998, 2012, 2015 The NetBSD Foundation, Inc.
@@ -32,7 +32,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: usbdi.c,v 1.180 2018/11/16 00:34:50 manu Exp $");
+__KERNEL_RCSID(0, "$NetBSD: usbdi.c,v 1.181 2019/01/10 22:13:07 skrll Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_usb.h"
@@ -258,13 +258,14 @@
        LIST_REMOVE(pipe, up_next);
        pipe->up_endpoint->ue_refcnt--;
 
+       pipe->up_methods->upm_close(pipe);
+
        if (pipe->up_intrxfer != NULL) {
                usbd_unlock_pipe(pipe);
                usbd_destroy_xfer(pipe->up_intrxfer);
                usbd_lock_pipe(pipe);
        }
 
-       pipe->up_methods->upm_close(pipe);
        usbd_unlock_pipe(pipe);
        kmem_free(pipe, pipe->up_dev->ud_bus->ub_pipesize);