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=-20.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable 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 9017FC07E9B for ; Mon, 19 Jul 2021 15:44:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7B0D8611CE for ; Mon, 19 Jul 2021 15:44:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343886AbhGSPEH (ORCPT ); Mon, 19 Jul 2021 11:04:07 -0400 Received: from mail.kernel.org ([198.145.29.99]:54776 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244710AbhGSOhs (ORCPT ); Mon, 19 Jul 2021 10:37:48 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 88B7861205; Mon, 19 Jul 2021 15:17:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626707854; bh=cjIp7d6fAt+PZjTVIFvPwlCvRcdLEmBeXCKn5JVqF1E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Tcw0X8kfEpTdWwQG4zc5PTJvDh22G5aUNtJXr/bEwpyTkSyekYRxv6TCQ942Izzii NRlhhVJnQsmztfC3O9BmJoQcm4ztsWslRyOAkmKAA/UQxjXTFVULkCbsQmHbayz5T2 SO638ABavT+vt5MeEfi38cF3Rn3U/6qk8TW8gLD4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lv Yunlong , Hans Verkuil , Mauro Carvalho Chehab , Sasha Levin Subject: [PATCH 4.14 084/315] media: exynos4-is: Fix a use after free in isp_video_release Date: Mon, 19 Jul 2021 16:49:33 +0200 Message-Id: <20210719144945.641656061@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210719144942.861561397@linuxfoundation.org> References: <20210719144942.861561397@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Lv Yunlong [ Upstream commit 01fe904c9afd26e79c1f73aa0ca2e3d785e5e319 ] In isp_video_release, file->private_data is freed via _vb2_fop_release()->v4l2_fh_release(). But the freed file->private_data is still used in v4l2_fh_is_singular_file() ->v4l2_fh_is_singular(file->private_data), which is a use after free bug. My patch uses a variable 'is_singular_file' to avoid the uaf. v3: https://lore.kernel.org/patchwork/patch/1419058/ Fixes: 34947b8aebe3f ("[media] exynos4-is: Add the FIMC-IS ISP capture DMA driver") Signed-off-by: Lv Yunlong Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin --- drivers/media/platform/exynos4-is/fimc-isp-video.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/media/platform/exynos4-is/fimc-isp-video.c b/drivers/media/platform/exynos4-is/fimc-isp-video.c index 39340abefd14..c9ef74ee476a 100644 --- a/drivers/media/platform/exynos4-is/fimc-isp-video.c +++ b/drivers/media/platform/exynos4-is/fimc-isp-video.c @@ -308,17 +308,20 @@ static int isp_video_release(struct file *file) struct fimc_is_video *ivc = &isp->video_capture; struct media_entity *entity = &ivc->ve.vdev.entity; struct media_device *mdev = entity->graph_obj.mdev; + bool is_singular_file; mutex_lock(&isp->video_lock); - if (v4l2_fh_is_singular_file(file) && ivc->streaming) { + is_singular_file = v4l2_fh_is_singular_file(file); + + if (is_singular_file && ivc->streaming) { media_pipeline_stop(entity); ivc->streaming = 0; } _vb2_fop_release(file, NULL); - if (v4l2_fh_is_singular_file(file)) { + if (is_singular_file) { fimc_pipeline_call(&ivc->ve, close); mutex_lock(&mdev->graph_mutex); -- 2.30.2