From patchwork Thu Nov 17 06:21:52 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: cuigaosheng X-Patchwork-Id: 13046211 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 B339AC4332F for ; Thu, 17 Nov 2022 06:21:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238829AbiKQGV5 (ORCPT ); Thu, 17 Nov 2022 01:21:57 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60670 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232139AbiKQGV4 (ORCPT ); Thu, 17 Nov 2022 01:21:56 -0500 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A8F5030F62 for ; Wed, 16 Nov 2022 22:21:55 -0800 (PST) Received: from kwepemi500012.china.huawei.com (unknown [172.30.72.54]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4NCV9J2bx9zJnpN; Thu, 17 Nov 2022 14:18:44 +0800 (CST) Received: from cgs.huawei.com (10.244.148.83) by kwepemi500012.china.huawei.com (7.221.188.12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Thu, 17 Nov 2022 14:21:53 +0800 From: Gaosheng Cui To: , , , , CC: , , Subject: [PATCH] dma-buf: Fix possible UAF in dma_buf_export Date: Thu, 17 Nov 2022 14:21:52 +0800 Message-ID: <20221117062152.3029018-1-cuigaosheng1@huawei.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-Originating-IP: [10.244.148.83] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To kwepemi500012.china.huawei.com (7.221.188.12) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Smatch report warning as follows: drivers/dma-buf/dma-buf.c:681 dma_buf_export() warn: '&dmabuf->list_node' not removed from list If dma_buf_stats_setup() fails in dma_buf_export(), goto err_sysfs and dmabuf will be freed, but dmabuf->list_node will not be removed from db_list.head, then list traversal may cause UAF. Fix by removeing it from db_list.head before free(). Fixes: ef3a6b70507a ("dma-buf: call dma_buf_stats_setup after dmabuf is in valid list") Signed-off-by: Gaosheng Cui --- drivers/dma-buf/dma-buf.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index b809513b03fe..6848f50226d5 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -675,6 +675,9 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info) return dmabuf; err_sysfs: + mutex_lock(&db_list.lock); + list_del(&dmabuf->list_node); + mutex_unlock(&db_list.lock); /* * Set file->f_path.dentry->d_fsdata to NULL so that when * dma_buf_release() gets invoked by dentry_ops, it exits