From patchwork Tue Feb 12 23:47:59 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wen Yang X-Patchwork-Id: 10808981 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1A2781390 for ; Tue, 12 Feb 2019 23:49:06 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EEFD82BA41 for ; Tue, 12 Feb 2019 23:49:05 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id DEDC82BABA; Tue, 12 Feb 2019 23:49:05 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B82CA2BA41 for ; Tue, 12 Feb 2019 23:49:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731439AbfBLXtE (ORCPT ); Tue, 12 Feb 2019 18:49:04 -0500 Received: from mxhk.zte.com.cn ([63.217.80.70]:14854 "EHLO mxhk.zte.com.cn" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728792AbfBLXtE (ORCPT ); Tue, 12 Feb 2019 18:49:04 -0500 Received: from mse01.zte.com.cn (unknown [10.30.3.20]) by Forcepoint Email with ESMTPS id 97E5AD5EE8295C9A5969; Wed, 13 Feb 2019 07:49:01 +0800 (CST) Received: from notes_smtp.zte.com.cn ([10.30.1.239]) by mse01.zte.com.cn with ESMTP id x1CNmuEI002250; Wed, 13 Feb 2019 07:48:56 +0800 (GMT-8) (envelope-from wen.yang99@zte.com.cn) Received: from fox-host8.localdomain ([10.74.120.8]) by szsmtp06.zte.com.cn (Lotus Domino Release 8.5.3FP6) with ESMTP id 2019021307491490-25782404 ; Wed, 13 Feb 2019 07:49:14 +0800 From: Wen Yang To: m.szyprowski@samsung.com Cc: mchehab@kernel.org, linux-samsung-soc@vger.kernel.org, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, xue.zhihong@zte.com.cn, wang.yi59@zte.com.cn, Wen Yang , "Hans Verkuil (hansverk)" , Hans Verkuil , Wen Yang Subject: [PATCH v2 3/4] media: s5p-cec: fix possible object reference leak Date: Wed, 13 Feb 2019 07:47:59 +0800 Message-Id: <1550015279-42723-1-git-send-email-wen.yang99@zte.com.cn> X-Mailer: git-send-email 1.8.3.1 X-MIMETrack: Itemize by SMTP Server on SZSMTP06/server/zte_ltd(Release 8.5.3FP6|November 21, 2013) at 2019-02-13 07:49:14, Serialize by Router on notes_smtp/zte_ltd(Release 9.0.1FP7|August 17, 2016) at 2019-02-13 07:48:48, Serialize complete at 2019-02-13 07:48:48 X-MAIL: mse01.zte.com.cn x1CNmuEI002250 Sender: linux-samsung-soc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-samsung-soc@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The call to of_parse_phandle() returns a node pointer with refcount incremented thus it must be explicitly decremented here after the last usage. The of_find_device_by_node() takes a reference to the underlying device structure, we also should release that reference. This patch fixes those two issues. Hans Verkuil says: The cec driver should never take a reference of the hdmi device. It never accesses the HDMI device, it only needs the HDMI device pointer as a key in the notifier list. The real problem is that several CEC drivers take a reference of the HDMI device and never release it. So those drivers need to be fixed. Fixes: a93d429b51fb ("[media] s5p-cec: add cec-notifier support, move out of staging") Suggested-by: Hans Verkuil (hansverk) Signed-off-by: Wen Yang Cc: Hans Verkuil (hansverk) Cc: Hans Verkuil Cc: Marek Szyprowski Cc: Mauro Carvalho Chehab Cc: Wen Yang Cc: linux-samsung-soc@vger.kernel.org Cc: linux-media@vger.kernel.org Acked-by: Marek Szyprowski --- v2->v1: - move of_node_put() to just after the 'hdmi_dev = of_find_device_by_node(np)'. - put_device() can be done before the cec = devm_kzalloc line. drivers/media/platform/s5p-cec/s5p_cec.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/media/platform/s5p-cec/s5p_cec.c b/drivers/media/platform/s5p-cec/s5p_cec.c index 8837e26..1f5c355 100644 --- a/drivers/media/platform/s5p-cec/s5p_cec.c +++ b/drivers/media/platform/s5p-cec/s5p_cec.c @@ -192,9 +192,11 @@ static int s5p_cec_probe(struct platform_device *pdev) return -ENODEV; } hdmi_dev = of_find_device_by_node(np); + of_node_put(np); if (hdmi_dev == NULL) return -EPROBE_DEFER; + put_device(&hdmi_dev->dev); cec = devm_kzalloc(&pdev->dev, sizeof(*cec), GFP_KERNEL); if (!cec) return -ENOMEM;