On Wed, Nov 28, 2018 at 10:22:21AM -0500, Sasha Levin wrote:
On Tue, Nov 27, 2018 at 07:16:56AM -0800, Johan Hovold wrote:
On Sun, Nov 11, 2018 at 08:17:40AM -0800, Greg Kroah-Hartman wrote:
The patch below does not apply to the 4.9-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 stable@vger.kernel.org.
This one also depends on
36156f9241cb ("of: add helper to lookup compatible child node")
It seems to have more dependencies for 4.9.
Apparently just a trivial context change due to 4bf99144d2b4 ("drm: Convert to using %pOF instead of full_name").
Compile-tested backport below.
Johan
From 25904658b8a0975376a9118cfc07f5f3ebb1ea34 Mon Sep 17 00:00:00 2001
From: Johan Hovold johan@kernel.org Date: Mon, 27 Aug 2018 10:21:46 +0200 Subject: [PATCH] drm/mediatek: fix OF sibling-node lookup
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 stable@vger.kernel.org # 4.8 Cc: Junzhi Zhao junzhi.zhao@mediatek.com Cc: Philipp Zabel p.zabel@pengutronix.de Cc: CK Hu ck.hu@mediatek.com Cc: David Airlie airlied@linux.ie Signed-off-by: Johan Hovold johan@kernel.org Signed-off-by: Rob Herring robh@kernel.org [ johan: backport to 4.9 ] Signed-off-by: Johan Hovold johan@kernel.org --- drivers/gpu/drm/mediatek/mtk_hdmi.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/mediatek/mtk_hdmi.c b/drivers/gpu/drm/mediatek/mtk_hdmi.c index e097780752f6..863d030786e5 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 %s\n", cec_np->full_name); + of_node_put(cec_np); return -EPROBE_DEFER; } + of_node_put(cec_np); hdmi->cec_dev = &cec_pdev->dev;
/*