From patchwork Fri Sep 4 06:37:44 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Zengtao (B)" X-Patchwork-Id: 11755893 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id EA849618 for ; Fri, 4 Sep 2020 06:39:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DB53620748 for ; Fri, 4 Sep 2020 06:39:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728154AbgIDGjL (ORCPT ); Fri, 4 Sep 2020 02:39:11 -0400 Received: from szxga04-in.huawei.com ([45.249.212.190]:10811 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726251AbgIDGjL (ORCPT ); Fri, 4 Sep 2020 02:39:11 -0400 Received: from DGGEMS406-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id A6DF026C41212103A2AA; Fri, 4 Sep 2020 14:39:05 +0800 (CST) Received: from localhost.localdomain (10.67.165.24) by DGGEMS406-HUB.china.huawei.com (10.3.19.206) with Microsoft SMTP Server id 14.3.487.0; Fri, 4 Sep 2020 14:38:59 +0800 From: Zeng Tao To: CC: Zeng Tao , stable , "Alan Stern" , chenqiwu , , Subject: [PATCH] usb: core: fix slab-out-of-bounds Read in read_descriptors Date: Fri, 4 Sep 2020 14:37:44 +0800 Message-ID: <1599201467-11000-1-git-send-email-prime.zeng@hisilicon.com> X-Mailer: git-send-email 2.8.1 MIME-Version: 1.0 X-Originating-IP: [10.67.165.24] X-CFilter-Loop: Reflected Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org The USB device descriptor may get changed between two consecutive enumerations on the same device for some reason, such as DFU or malicius device. In that case, we may access the changing descriptor if we don't take the device lock here. The issue is reported: https://syzkaller.appspot.com/bug?id=901a0d9e6519ef8dc7acab25344bd287dd3c7be9 Cc: stable Cc: Alan Stern Reported-by: syzbot+256e56ddde8b8957eabd@syzkaller.appspotmail.com Fixes: 217a9081d8e6 ("USB: add all configs to the "descriptors" attribute") Signed-off-by: Zeng Tao --- drivers/usb/core/sysfs.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c index a2ca38e..8d13419 100644 --- a/drivers/usb/core/sysfs.c +++ b/drivers/usb/core/sysfs.c @@ -889,7 +889,11 @@ read_descriptors(struct file *filp, struct kobject *kobj, size_t srclen, n; int cfgno; void *src; + int retval; + retval = usb_lock_device_interruptible(udev); + if (retval < 0) + return -EINTR; /* The binary attribute begins with the device descriptor. * Following that are the raw descriptor entries for all the * configurations (config plus subsidiary descriptors). @@ -914,6 +918,7 @@ read_descriptors(struct file *filp, struct kobject *kobj, off -= srclen; } } + usb_unlock_device(udev); return count - nleft; }