From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:37518 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732921AbeKLISe (ORCPT ); Mon, 12 Nov 2018 03:18:34 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Junzhi Zhao , Philipp Zabel , CK Hu , David Airlie , Johan Hovold , Rob Herring Subject: [PATCH 4.19 312/361] drm/mediatek: fix OF sibling-node lookup Date: Sun, 11 Nov 2018 14:20:59 -0800 Message-Id: <20181111221658.365211527@linuxfoundation.org> In-Reply-To: <20181111221619.915519183@linuxfoundation.org> References: <20181111221619.915519183@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Johan Hovold commit ceff2f4dcd44abf35864d9a99f85ac619e89a01d upstream. Use the new of_get_compatible_child() helper to lookup the sibling instead of using of_find_compatible_node(), which searches the entire tree from a given start node and thus can return an unrelated (i.e. non-sibling) node. This also addresses a potential use-after-free (e.g. after probe deferral) as the tree-wide helper drops a reference to its first argument (i.e. the parent device node). While at it, also fix the related cec-node reference leak. Fixes: 8f83f26891e1 ("drm/mediatek: Add HDMI support") Cc: stable # 4.8 Cc: Junzhi Zhao Cc: Philipp Zabel Cc: CK Hu Cc: David Airlie Signed-off-by: Johan Hovold Signed-off-by: Rob Herring Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/mediatek/mtk_hdmi.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/drivers/gpu/drm/mediatek/mtk_hdmi.c +++ b/drivers/gpu/drm/mediatek/mtk_hdmi.c @@ -1446,8 +1446,7 @@ static int mtk_hdmi_dt_parse_pdata(struc } /* The CEC module handles HDMI hotplug detection */ - cec_np = of_find_compatible_node(np->parent, NULL, - "mediatek,mt8173-cec"); + cec_np = of_get_compatible_child(np->parent, "mediatek,mt8173-cec"); if (!cec_np) { dev_err(dev, "Failed to find CEC node\n"); return -EINVAL; @@ -1457,8 +1456,10 @@ static int mtk_hdmi_dt_parse_pdata(struc if (!cec_pdev) { dev_err(hdmi->dev, "Waiting for CEC device %pOF\n", cec_np); + of_node_put(cec_np); return -EPROBE_DEFER; } + of_node_put(cec_np); hdmi->cec_dev = &cec_pdev->dev; /*