From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf1-f194.google.com ([209.85.210.194]:39627 "EHLO mail-pf1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729342AbeK1CQc (ORCPT ); Tue, 27 Nov 2018 21:16:32 -0500 Received: by mail-pf1-f194.google.com with SMTP id c72so8523819pfc.6 for ; Tue, 27 Nov 2018 07:18:18 -0800 (PST) Date: Tue, 27 Nov 2018 07:17:07 -0800 From: Johan Hovold To: gregkh@linuxfoundation.org Cc: johan@kernel.org, airlied@linux.ie, ck.hu@mediatek.com, junzhi.zhao@mediatek.com, p.zabel@pengutronix.de, robh@kernel.org, stable@vger.kernel.org Subject: Re: FAILED: patch "[PATCH] drm/mediatek: fix OF sibling-node lookup" failed to apply to 4.14-stable tree Message-ID: <20181127151707.GQ2403@localhost> References: <1541953116222224@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1541953116222224@kroah.com> Sender: stable-owner@vger.kernel.org List-ID: On Sun, Nov 11, 2018 at 08:18:36AM -0800, Greg Kroah-Hartman wrote: > > The patch below does not apply to the 4.14-stable tree. > If someone wants it applied there, or to any other stable or longterm > tree, then please email the backport, including the original git commit > id to . This one also depends on 36156f9241cb ("of: add helper to lookup compatible child node") Johan > ------------------ original commit in Linus's tree ------------------ > > From ceff2f4dcd44abf35864d9a99f85ac619e89a01d Mon Sep 17 00:00:00 2001 > From: Johan Hovold > Date: Mon, 27 Aug 2018 10:21:46 +0200 > Subject: [PATCH] drm/mediatek: fix OF sibling-node lookup > > 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 > > diff --git a/drivers/gpu/drm/mediatek/mtk_hdmi.c b/drivers/gpu/drm/mediatek/mtk_hdmi.c > index 2d45d1dd9554..643f5edd68fe 100644 > --- 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(struct mtk_hdmi *hdmi, > } > > /* 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(struct mtk_hdmi *hdmi, > 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; > > /* >