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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 97A91CDB474 for ; Fri, 20 Oct 2023 08:20:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235697AbjJTIUV (ORCPT ); Fri, 20 Oct 2023 04:20:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39642 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230217AbjJTIUR (ORCPT ); Fri, 20 Oct 2023 04:20:17 -0400 Received: from madras.collabora.co.uk (madras.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e5ab]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5EEEAB0; Fri, 20 Oct 2023 01:20:15 -0700 (PDT) Received: from [192.168.1.100] (2-237-20-237.ip236.fastwebnet.it [2.237.20.237]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: kholk11) by madras.collabora.co.uk (Postfix) with ESMTPSA id 60F966607352; Fri, 20 Oct 2023 09:20:13 +0100 (BST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1697790014; bh=RSQ5/DMeBnjdqm4h5GEDNo41Y8NPcwqWmF2hl3CzU4Y=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=LTr/BwXEXjwM28l/WBLy3g4Y6rSO7GmucFVzcI6oDTvGsGkpsDiWKWtxsyA/UVPgO godKZqiaTA8xWdepYuPjuEOg1rJ8pG7MrICvM7PLNO8wrymvthXDzPCKoWtZj39ts4 XxNQez3PUaVRWnI1iMFG6nJp7yYgnckhziuZ8yAJ5J9SHiW2m6z1cV0f7eDMT2IZ/i 56Ykk4SQwQoFQHUAxA2Ce2pGKQxe5iIOcGD1X96lNDl+3daRKbujVdr+ZmJ8f/SQ+C 43fnemdqYE1JnQRm2rxKJsly8AdjEh+0TT9H3iXfIvL4Hv5isgvxMUVb3h1i1Mg3km Vr7OwHYB0r7Xw== Message-ID: <8b799079-fd98-46ba-a2cd-04ecf0c0df1d@collabora.com> Date: Fri, 20 Oct 2023 10:20:13 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] media: mtk-jpeg: Fix use after free bug due to error path handling in mtk_jpeg_dec_device_run Content-Language: en-US To: Zheng Wang , dmitry.osipenko@collabora.com Cc: Kyrie.Wu@mediatek.com, bin.liu@mediatek.com, mchehab@kernel.org, matthias.bgg@gmail.com, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, Irui.Wang@mediatek.com, security@kernel.org, hackerzheng666@gmail.com, 1395428693sheep@gmail.com, alex000young@gmail.com, amergnat@baylibre.com, wenst@chromium.org, stable@vger.kernel.org References: <20231020040732.2499269-1-zyytlz.wz@163.com> From: AngeloGioacchino Del Regno In-Reply-To: <20231020040732.2499269-1-zyytlz.wz@163.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Il 20/10/23 06:07, Zheng Wang ha scritto: > In mtk_jpeg_probe, &jpeg->job_timeout_work is bound with > mtk_jpeg_job_timeout_work. > > In mtk_jpeg_dec_device_run, if error happens in > mtk_jpeg_set_dec_dst, it will finally start the worker while > mark the job as finished by invoking v4l2_m2m_job_finish. > > There are two methods to trigger the bug. If we remove the > module, it which will call mtk_jpeg_remove to make cleanup. > The possible sequence is as follows, which will cause a > use-after-free bug. > > CPU0 CPU1 > mtk_jpeg_dec_... | > start worker | > |mtk_jpeg_job_timeout_work > mtk_jpeg_remove | > v4l2_m2m_release | > kfree(m2m_dev); | > | > | v4l2_m2m_get_curr_priv > | m2m_dev->curr_ctx //use > > If we close the file descriptor, which will call mtk_jpeg_release, > it will have a similar sequence. > > Fix this bug by start timeout worker only if started jpegdec worker > successfully so the v4l2_m2m_job_finish will only be called on > either mtk_jpeg_job_timeout_work or mtk_jpeg_dec_device_run. > > This patch also reverts commit c677d7ae8314 > ("media: mtk-jpeg: Fix use after free bug due to uncanceled work") > for this patch also fixed the use-after-free bug mentioned before. > Before mtk_jpeg_remove is invoked, mtk_jpeg_release must be invoked > to close opened files. And it will call v4l2_m2m_cancel_job to wait > for the timeout worker finished so the canceling in mtk_jpeg_remove > is unnecessary. > > Fixes: b2f0d2724ba4 ("[media] vcodec: mediatek: Add Mediatek JPEG Decoder Driver") > Signed-off-by: Zheng Wang > Signed-off-by: Dmitry Osipenko Reviewed-by: AngeloGioacchino Del Regno