linux-kernel - [PATCH v3 08/10] drm/display: hdmi_state_helper: don't generate unsupported InfoFrames

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-Id: <20251224-limit-infoframes-2-v3-8-7fd3cacfefed@oss.qualcomm.com>
Date: Wed, 24 Dec 2025 03:02:57 +0200
From: Dmitry Baryshkov <dmitry.baryshkov@....qualcomm.com>
To: Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
        Maxime Ripard <mripard@...nel.org>,
        Thomas Zimmermann <tzimmermann@...e.de>,
        David Airlie <airlied@...il.com>, Simona Vetter <simona@...ll.ch>,
        Dave Stevenson <dave.stevenson@...pberrypi.com>,
        Maíra Canal <mcanal@...lia.com>,
        Raspberry Pi Kernel Maintenance <kernel-list@...pberrypi.com>,
        Chen-Yu Tsai <wens@...nel.org>,
        Jernej Skrabec <jernej.skrabec@...il.com>,
        Samuel Holland <samuel@...lland.org>,
        Andrzej Hajda <andrzej.hajda@...el.com>,
        Neil Armstrong <neil.armstrong@...aro.org>,
        Robert Foss <rfoss@...nel.org>,
        Laurent Pinchart <Laurent.pinchart@...asonboard.com>,
        Jonas Karlman <jonas@...boo.se>, Liu Ying <victor.liu@....com>,
        Chun-Kuang Hu <chunkuang.hu@...nel.org>,
        Philipp Zabel <p.zabel@...gutronix.de>,
        Matthias Brugger <matthias.bgg@...il.com>,
        AngeloGioacchino Del Regno <angelogioacchino.delregno@...labora.com>,
        Rob Clark <robin.clark@....qualcomm.com>,
        Dmitry Baryshkov <lumag@...nel.org>,
        Abhinav Kumar <abhinav.kumar@...ux.dev>,
        Jessica Zhang <jesszhan0024@...il.com>, Sean Paul <sean@...rly.run>,
        Marijn Suijten <marijn.suijten@...ainline.org>,
        Sandy Huang <hjc@...k-chips.com>,
        Heiko Stübner <heiko@...ech.de>,
        Andy Yan <andy.yan@...k-chips.com>
Cc: dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org, linux-sunxi@...ts.linux.dev,
        linux-mediatek@...ts.infradead.org, linux-arm-msm@...r.kernel.org,
        freedreno@...ts.freedesktop.org, linux-rockchip@...ts.infradead.org
Subject: [PATCH v3 08/10] drm/display: hdmi_state_helper: don't generate
 unsupported InfoFrames

There is little point in generating InfoFrames which are not supported
by the driver. Skip generating the unsupported InfoFrames, making sure
that the kernel never tries to write the unsupported frame. As there are
no remaining usecases, change write_infoframe / clear_infoframe helpers
return an error if the corresponding callback is NULL.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@....qualcomm.com>
---
 drivers/gpu/drm/display/drm_hdmi_state_helper.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/display/drm_hdmi_state_helper.c b/drivers/gpu/drm/display/drm_hdmi_state_helper.c
index e8556bf9e1da..a1d16762ac7a 100644
--- a/drivers/gpu/drm/display/drm_hdmi_state_helper.c
+++ b/drivers/gpu/drm/display/drm_hdmi_state_helper.c
@@ -718,6 +718,9 @@ static int hdmi_generate_spd_infoframe(const struct drm_connector *connector,
 
 	infoframe->set = false;
 
+	if (!connector->hdmi.funcs->spd.write_infoframe)
+		return 0;
+
 	ret = hdmi_spd_infoframe_init(frame,
 				      connector->hdmi.vendor,
 				      connector->hdmi.product);
@@ -742,6 +745,9 @@ static int hdmi_generate_hdr_infoframe(const struct drm_connector *connector,
 
 	infoframe->set = false;
 
+	if (!connector->hdmi.funcs->hdr_drm.write_infoframe)
+		return 0;
+
 	if (connector->max_bpc < 10)
 		return 0;
 
@@ -902,7 +908,7 @@ static int clear_infoframe(struct drm_connector *connector,
 
 	if (!funcs->clear_infoframe) {
 		drm_dbg_kms(dev, "Function not implemented, bailing.\n");
-		return 0;
+		return -EOPNOTSUPP;
 	}
 
 	ret = funcs->clear_infoframe(connector);
@@ -928,7 +934,7 @@ static int write_infoframe(struct drm_connector *connector,
 
 	if (!funcs->write_infoframe) {
 		drm_dbg_kms(dev, "Function not implemented, bailing.\n");
-		return 0; /* XXX: temporal until we stop generating unsupported frames */
+		return -EOPNOTSUPP;
 	}
 
 	len = hdmi_infoframe_pack(&new_frame->data, buffer, sizeof(buffer));

-- 
2.47.3