From patchwork Mon Mar 13 15:41:32 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zheng Wang X-Patchwork-Id: 90445 Received: from vger.kernel.org ([23.128.96.18]) by www.linuxtv.org with esmtp (Exim 4.92) (envelope-from ) id 1pbkJQ-00FzcT-AM; Mon, 13 Mar 2023 15:42:12 +0000 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229682AbjCMPmJ (ORCPT + 1 other); Mon, 13 Mar 2023 11:42:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59750 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229543AbjCMPmI (ORCPT ); Mon, 13 Mar 2023 11:42:08 -0400 Received: from m12.mail.163.com (m12.mail.163.com [123.126.96.233]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 5057D53724; Mon, 13 Mar 2023 08:42:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:Subject:Date:Message-Id:MIME-Version; bh=NMeHq c9vEtUERKAOCOKjGmVkf5YkMepOMEfhtaswEhc=; b=em7N6x0m+8FcZgIVUSuhU HnWkEZhrTFz+w29FDBYiesKxWe2N5jlOOVn09DuSUMytcqnF4H1qqS7iWTZ5evNM OwyRpJDpK7FBbt97Eu24mZFq9vEpchwN3RErZboGOkViLFU8wIG1YCIW6ydh/G1E YBdeRU+aC1FoaJB0JglJ9M= Received: from leanderwang-LC2.localdomain (unknown [111.206.145.21]) by smtp19 (Coremail) with SMTP id R9xpCgD3_rItRA9kgCPoHQ--.36544S2; Mon, 13 Mar 2023 23:41:33 +0800 (CST) From: Zheng Wang To: ezequiel@vanguardiasur.com.ar Cc: p.zabel@pengutronix.de, mchehab@kernel.org, linux-media@vger.kernel.org, linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org, hackerzheng666@gmail.com, 1395428693sheep@gmail.com, alex000young@gmail.com, hverkuil@xs4all.nl, Zheng Wang Subject: [PATCH v3] media: hantro: fix use after free bug in hantro_remove due to race condition Date: Mon, 13 Mar 2023 23:41:32 +0800 Message-Id: <20230313154132.3684181-1-zyytlz.wz@163.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-CM-TRANSID: R9xpCgD3_rItRA9kgCPoHQ--.36544S2 X-Coremail-Antispam: 1Uf129KBjvJXoW7Wry3Xw4kJw47Jr4rWr4kZwb_yoW8Cw1DpF W3G3y5KrWjqr47KFn7tay09ayfCasFqF4jgrZruw13JF9xtr9rurySyF48AF98JrZ3ZF4a vF4jqrW8Z3y2vFJanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x0ziaZXrUUUUU= X-Originating-IP: [111.206.145.21] X-CM-SenderInfo: h2113zf2oz6qqrwthudrp/xtbBzgsxU2I0XntM5AADs- X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM, RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-LSpam-Score: -2.5 (--) X-LSpam-Report: No, score=-2.5 required=5.0 tests=BAYES_00=-1.9,DKIM_SIGNED=0.1,DKIM_VALID=-0.1,DKIM_VALID_AU=-0.1,FREEMAIL_FORGED_FROMDOMAIN=0.001,FREEMAIL_FROM=0.001,HEADER_FROM_DIFFERENT_DOMAINS=0.5,MAILING_LIST_MULTI=-1 autolearn=ham autolearn_force=no In hantro_probe, vpu->watchdog_work is bound with hantro_watchdog. Then hantro_end_prepare_run may be called to start the work. If we close the file or remove the module which will call hantro_release and hantro_remove to make cleanup, there may be an unfinished work. The possible sequence is as follows, which will cause a typical UAF bug. The same thing will happen in hantro_release, and use ctx after freeing it. Fix it by canceling the work before cleanup in hantro_release. CPU0 CPU1 |hantro_watchdog hantro_remove | v4l2_m2m_release | kfree(m2m_dev); | | | v4l2_m2m_get_curr_priv | m2m_dev->curr_ctx //use Signed-off-by: Zheng Wang --- v3: - use cancel_delayed_work_sync instead of cancel_delayed_work and add it to hantro_release suggested by Hans Verkuil v2: - move the cancel-work-related code to hantro_remove suggested by Hans Verkuil --- drivers/media/platform/verisilicon/hantro_drv.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/media/platform/verisilicon/hantro_drv.c b/drivers/media/platform/verisilicon/hantro_drv.c index b0aeedae7b65..86a4c0fa8c7d 100644 --- a/drivers/media/platform/verisilicon/hantro_drv.c +++ b/drivers/media/platform/verisilicon/hantro_drv.c @@ -597,6 +597,7 @@ static int hantro_release(struct file *filp) struct hantro_ctx *ctx = container_of(filp->private_data, struct hantro_ctx, fh); + cancel_delayed_work_sync(&ctx->dev->watchdog_work); /* * No need for extra locking because this was the last reference * to this file. @@ -1099,6 +1100,7 @@ static int hantro_remove(struct platform_device *pdev) v4l2_info(&vpu->v4l2_dev, "Removing %s\n", pdev->name); + cancel_delayed_work_sync(&vpu->watchdog_work); media_device_unregister(&vpu->mdev); hantro_remove_dec_func(vpu); hantro_remove_enc_func(vpu);