From patchwork Wed Jan 15 17:46:28 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Carpenter X-Patchwork-Id: 11335493 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 DB79592A for ; Wed, 15 Jan 2020 17:49:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B9D7F24656 for ; Wed, 15 Jan 2020 17:49:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="it64FJ85" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729026AbgAORs4 (ORCPT ); Wed, 15 Jan 2020 12:48:56 -0500 Received: from aserp2120.oracle.com ([141.146.126.78]:49894 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729012AbgAORsz (ORCPT ); Wed, 15 Jan 2020 12:48:55 -0500 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.27/8.16.0.27) with SMTP id 00FHmKXS053853; Wed, 15 Jan 2020 17:48:40 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : mime-version : content-type : in-reply-to; s=corp-2019-08-05; bh=YbWh9/KT2LGMmOyRVkj1TC9eOP8jW/x+M/Q9ZVfRcSs=; b=it64FJ854+XG7LbFSU0DKjYvxWgHHeDmSUJBpOyRfNgPJ4pf7crNKOjcBek0ht/izJWK HcCw0TN5WcPt6RqlG2GFiMiUk/OdoNwh7gqaHw2fFE1SNjTR77jrEdShDtDW6Q3KOEmM UCweRx/LN7But1MoV+eCZdPw78SMmotzz8+sCgeaRMzNPFk+BxP69xn3z5tH2AqTnm5V 2soYlORAmIWnwMpgMBbpfh/qnEOQf5oEgyw89k05Vg23EeyLocN4hbgeCEZIQlO1fbIN fSODo/tD9JmjWEPmwniL7LJamcHIkjipq2R9U9cYXx3/Gh94zgqWe5PbNn1YaxJNeBtb KA== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by aserp2120.oracle.com with ESMTP id 2xf73twkr4-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 15 Jan 2020 17:48:40 +0000 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.27/8.16.0.27) with SMTP id 00FHd2Oh019577; Wed, 15 Jan 2020 17:46:39 GMT Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by userp3030.oracle.com with ESMTP id 2xhy21t33w-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 15 Jan 2020 17:46:39 +0000 Received: from abhmp0007.oracle.com (abhmp0007.oracle.com [141.146.116.13]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id 00FHkbhc016060; Wed, 15 Jan 2020 17:46:37 GMT Received: from kili.mountain (/129.205.23.165) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 15 Jan 2020 09:46:37 -0800 Date: Wed, 15 Jan 2020 20:46:28 +0300 From: Dan Carpenter , syzbot To: Jiri Kosina , Alan Stern , andreyknvl@google.com, syzkaller-bugs@googlegroups.com Cc: Benjamin Tissoires , linux-usb@vger.kernel.org, linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: [PATCH] HID: hiddev: Fix race in in hiddev_disconnect() Message-ID: <20200115174628.zxpxbpa6bwspjajg@kili.mountain> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-Mailer: git-send-email haha only kidding User-Agent: NeoMutt/20170113 (1.7.2) X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9501 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=2 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=978 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1911140001 definitions=main-2001150135 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9501 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=2 phishscore=0 bulkscore=0 spamscore=0 clxscore=1034 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1911140001 definitions=main-2001150136 Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Syzbot reports that "hiddev" is used after it's free in hiddev_disconnect(). The hiddev_disconnect() function sets "hiddev->exist = 0;" so hiddev_release() can free it as soon as we drop the "existancelock" lock. This patch moves the mutex_unlock(&hiddev->existancelock) until after we have finished using it. Reported-by: syzbot+784ccb935f9900cc7c9e@syzkaller.appspotmail.com Fixes: 7f77897ef2b6 ("HID: hiddev: fix potential use-after-free") Suggested-by: Alan Stern Signed-off-by: Dan Carpenter --- drivers/hid/usbhid/hiddev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/hid/usbhid/hiddev.c b/drivers/hid/usbhid/hiddev.c index a970b809d778..4140dea693e9 100644 --- a/drivers/hid/usbhid/hiddev.c +++ b/drivers/hid/usbhid/hiddev.c @@ -932,9 +932,9 @@ void hiddev_disconnect(struct hid_device *hid) hiddev->exist = 0; if (hiddev->open) { - mutex_unlock(&hiddev->existancelock); hid_hw_close(hiddev->hid); wake_up_interruptible(&hiddev->wait); + mutex_unlock(&hiddev->existancelock); } else { mutex_unlock(&hiddev->existancelock); kfree(hiddev);