From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 415A1C64E7A for ; Tue, 1 Dec 2020 06:25:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C833D2087D for ; Tue, 1 Dec 2020 06:25:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727007AbgLAGYu (ORCPT ); Tue, 1 Dec 2020 01:24:50 -0500 Received: from szxga04-in.huawei.com ([45.249.212.190]:8168 "EHLO szxga04-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726142AbgLAGYu (ORCPT ); Tue, 1 Dec 2020 01:24:50 -0500 Received: from DGGEMS411-HUB.china.huawei.com (unknown [172.30.72.58]) by szxga04-in.huawei.com (SkyGuard) with ESMTP id 4ClX9P1PFPz15W1S; Tue, 1 Dec 2020 14:23:37 +0800 (CST) Received: from localhost.localdomain.localdomain (10.175.113.25) by DGGEMS411-HUB.china.huawei.com (10.3.19.211) with Microsoft SMTP Server id 14.3.487.0; Tue, 1 Dec 2020 14:23:51 +0800 From: Qinglang Miao To: Cornelia Huck , Vineeth Vijayan , Peter Oberparleiter , "Heiko Carstens" , Vasily Gorbik , "Christian Borntraeger" CC: , , "Qinglang Miao" Subject: [PATCH] s390: cio: fix use-after-free in ccw_device_destroy_console Date: Tue, 1 Dec 2020 14:31:50 +0800 Message-ID: <20201201063150.82128-1-miaoqinglang@huawei.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.175.113.25] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org put_device calls release function which do kfree() inside. So following use of sch&cdev would cause use-after-free bugs. Fix these by simply adjusting the position of put_device. Fixes: 37db8985b211 ("s390/cio: add basic protected virtualization support") Reported-by: Hulk Robot Suggested-by: Cornelia Huck Signed-off-by: Qinglang Miao --- This patch is indeed a v2 of older one. Considering that the patch's name has changed, I think a normal prefix 'PATCH' is better. drivers/s390/cio/device.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c index b29fe8d50..33280ca18 100644 --- a/drivers/s390/cio/device.c +++ b/drivers/s390/cio/device.c @@ -1664,10 +1664,10 @@ void __init ccw_device_destroy_console(struct ccw_device *cdev) struct io_subchannel_private *io_priv = to_io_private(sch); set_io_private(sch, NULL); - put_device(&sch->dev); - put_device(&cdev->dev); dma_free_coherent(&sch->dev, sizeof(*io_priv->dma_area), io_priv->dma_area, io_priv->dma_area_dma); + put_device(&sch->dev); + put_device(&cdev->dev); kfree(io_priv); } -- 2.23.0