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From: Miles Krause via B4 Relay <devnull+mileskrause5200.gmail.com@kernel.org>
To: Neil Armstrong <neil.armstrong@linaro.org>,
	 Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
	 Maxime Ripard <mripard@kernel.org>,
	Thomas Zimmermann <tzimmermann@suse.de>,
	 David Airlie <airlied@gmail.com>,
	Simona Vetter <simona@ffwll.ch>,
	 Kevin Hilman <khilman@baylibre.com>,
	Jerome Brunet <jbrunet@baylibre.com>,
	 Martin Blumenstingl <martin.blumenstingl@googlemail.com>,
	 Nicolas Belin <nbelin@baylibre.com>,
	 Jagan Teki <jagan@amarulasolutions.com>
Cc: dri-devel@lists.freedesktop.org,
	linux-amlogic@lists.infradead.org,
	 linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org,
	 Miles Krause <mileskrause5200@gmail.com>
Subject: [PATCH] drm/meson: fix device_node leak in meson_encoder_dsi_probe()
Date: Sun, 06 Sep 2026 15:43:48 -0400	[thread overview]
Message-ID: <20260906-meson-dsi-of-node-leak-v1-1-9d183560279d@gmail.com> (raw)

From: Miles Krause <mileskrause5200@gmail.com>

meson_encoder_dsi_probe() looks up the DSI transceiver's device node
with of_graph_get_remote_node() and hands it to
of_drm_find_and_get_bridge(), but never drops the reference that the
lookup returned.

of_graph_get_remote_node() returns the node with its refcount
incremented, and of_drm_find_and_get_bridge() takes its own reference
on the bridge it finds, so 'remote' is leaked on every path once the
lookup succeeds: on the -EPROBE_DEFER return taken when no bridge is
found, and on a fully successful probe alike.

The two sibling encoders in this driver already handle this correctly.
meson_encoder_cvbs_probe() calls of_node_put(remote) immediately after
of_drm_find_and_get_bridge(), and meson_encoder_hdmi_probe() releases
the node both on its error path and after of_find_device_by_node().

Release the reference in the same place meson_encoder_cvbs_probe()
does, which covers both the error and the success path.

Fixes: 42dcf15f901c ("drm/meson: add DSI encoder")
Signed-off-by: Miles Krause <mileskrause5200@gmail.com>
---
 drivers/gpu/drm/meson/meson_encoder_dsi.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/meson/meson_encoder_dsi.c b/drivers/gpu/drm/meson/meson_encoder_dsi.c
index 3e422b612f74..3fe604496294 100644
--- a/drivers/gpu/drm/meson/meson_encoder_dsi.c
+++ b/drivers/gpu/drm/meson/meson_encoder_dsi.c
@@ -120,6 +120,7 @@ int meson_encoder_dsi_probe(struct meson_drm *priv)
 	}
 
 	meson_encoder_dsi->bridge.next_bridge = of_drm_find_and_get_bridge(remote);
+	of_node_put(remote);
 	if (!meson_encoder_dsi->bridge.next_bridge)
 		return dev_err_probe(priv->dev, -EPROBE_DEFER,
 				     "Failed to find DSI transceiver bridge\n");

---
base-commit: 88405f0ad1d5c680afe3ea0ce9345fa9e1deaac8
change-id: 20260906-meson-dsi-of-node-leak-744899da5712

Best regards,
-- 
Miles Krause <mileskrause5200@gmail.com>



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             reply	other threads:[~2026-09-06 19:44 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-09-06 19:43 Miles Krause via B4 Relay [this message]
2026-09-06 19:55 ` sashiko-bot
2026-09-10  7:23 ` Neil Armstrong

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