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From: Maxime Ripard <maxime@cerno.tech>
To: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
	Thomas Zimmermann <tzimmermann@suse.de>,
	Maxime Ripard <maxime@cerno.tech>,
	Daniel Vetter <daniel.vetter@intel.com>,
	David Airlie <airlied@linux.ie>, Eric Anholt <eric@anholt.net>
Cc: dri-devel@lists.freedesktop.org,
	bcm-kernel-feedback-list@broadcom.com,
	linux-rpi-kernel@lists.infradead.org,
	linux-arm-kernel@lists.infradead.org,
	Dave Stevenson <dave.stevenson@raspberrypi.com>
Subject: [PATCH v6 4/9] drm/vc4: hdmi: Don't access the connector state in reset if kmalloc fails
Date: Thu, 10 Dec 2020 15:23:24 +0100	[thread overview]
Message-ID: <20201210142329.10640-5-maxime@cerno.tech> (raw)
In-Reply-To: <20201210142329.10640-1-maxime@cerno.tech>

drm_atomic_helper_connector_reset uses kmalloc which, from an API
standpoint, can fail, and thus setting connector->state to NULL.
However, our reset hook then calls drm_atomic_helper_connector_tv_reset
that will access connector->state without checking if it's a valid
pointer or not.

Make sure we don't end up accessing a NULL pointer.

Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Suggested-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
---
 drivers/gpu/drm/vc4/vc4_hdmi.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index a88aa20beeb6..61039cc89d9d 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -171,7 +171,9 @@ static int vc4_hdmi_connector_get_modes(struct drm_connector *connector)
 static void vc4_hdmi_connector_reset(struct drm_connector *connector)
 {
 	drm_atomic_helper_connector_reset(connector);
-	drm_atomic_helper_connector_tv_reset(connector);
+
+	if (connector->state)
+		drm_atomic_helper_connector_tv_reset(connector);
 }
 
 static const struct drm_connector_funcs vc4_hdmi_connector_funcs = {
-- 
2.28.0


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

WARNING: multiple messages have this Message-ID (diff)
From: Maxime Ripard <maxime@cerno.tech>
To: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
	Thomas Zimmermann <tzimmermann@suse.de>,
	Maxime Ripard <maxime@cerno.tech>,
	Daniel Vetter <daniel.vetter@intel.com>,
	David Airlie <airlied@linux.ie>, Eric Anholt <eric@anholt.net>
Cc: dri-devel@lists.freedesktop.org,
	bcm-kernel-feedback-list@broadcom.com,
	linux-rpi-kernel@lists.infradead.org,
	linux-arm-kernel@lists.infradead.org,
	Dave Stevenson <dave.stevenson@raspberrypi.com>
Subject: [PATCH v6 4/9] drm/vc4: hdmi: Don't access the connector state in reset if kmalloc fails
Date: Thu, 10 Dec 2020 15:23:24 +0100	[thread overview]
Message-ID: <20201210142329.10640-5-maxime@cerno.tech> (raw)
In-Reply-To: <20201210142329.10640-1-maxime@cerno.tech>

drm_atomic_helper_connector_reset uses kmalloc which, from an API
standpoint, can fail, and thus setting connector->state to NULL.
However, our reset hook then calls drm_atomic_helper_connector_tv_reset
that will access connector->state without checking if it's a valid
pointer or not.

Make sure we don't end up accessing a NULL pointer.

Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Suggested-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
---
 drivers/gpu/drm/vc4/vc4_hdmi.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index a88aa20beeb6..61039cc89d9d 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -171,7 +171,9 @@ static int vc4_hdmi_connector_get_modes(struct drm_connector *connector)
 static void vc4_hdmi_connector_reset(struct drm_connector *connector)
 {
 	drm_atomic_helper_connector_reset(connector);
-	drm_atomic_helper_connector_tv_reset(connector);
+
+	if (connector->state)
+		drm_atomic_helper_connector_tv_reset(connector);
 }
 
 static const struct drm_connector_funcs vc4_hdmi_connector_funcs = {
-- 
2.28.0

_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

  parent reply	other threads:[~2020-12-10 14:25 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-10 14:23 [PATCH v6 0/9] drm/vc4: hdmi: Support the 10/12 bit output Maxime Ripard
2020-12-10 14:23 ` Maxime Ripard
2020-12-10 14:23 ` [PATCH v6 1/9] drm/vc4: hvs: Align the HVS atomic hooks to the new API Maxime Ripard
2020-12-10 14:23   ` Maxime Ripard
2020-12-10 14:23 ` [PATCH v6 2/9] drm/vc4: Pass the atomic state to encoder hooks Maxime Ripard
2020-12-10 14:23   ` Maxime Ripard
2020-12-10 14:23 ` [PATCH v6 3/9] drm/vc4: hdmi: Take into account the clock doubling flag in atomic_check Maxime Ripard
2020-12-10 14:23   ` Maxime Ripard
2020-12-10 14:23 ` Maxime Ripard [this message]
2020-12-10 14:23   ` [PATCH v6 4/9] drm/vc4: hdmi: Don't access the connector state in reset if kmalloc fails Maxime Ripard
2020-12-10 14:23 ` [PATCH v6 5/9] drm/vc4: hdmi: Create a custom connector state Maxime Ripard
2020-12-10 14:23   ` Maxime Ripard
2020-12-10 14:26   ` Maxime Ripard
2020-12-10 14:26     ` Maxime Ripard
2020-12-15 11:02   ` Dave Stevenson
2020-12-15 11:02     ` Dave Stevenson
2020-12-10 14:23 ` [PATCH v6 6/9] drm/vc4: hdmi: Store pixel frequency in the " Maxime Ripard
2020-12-10 14:23   ` Maxime Ripard
2020-12-10 14:23 ` [PATCH v6 7/9] drm/vc4: hdmi: Use the connector state pixel rate for the PHY Maxime Ripard
2020-12-10 14:23   ` Maxime Ripard
2020-12-10 14:23 ` [PATCH v6 8/9] drm/vc4: hdmi: Limit the BCM2711 to the max without scrambling Maxime Ripard
2020-12-10 14:23   ` Maxime Ripard
2020-12-10 14:23 ` [PATCH v6 9/9] drm/vc4: hdmi: Enable 10/12 bpc output Maxime Ripard
2020-12-10 14:23   ` Maxime Ripard
2020-12-15 11:04   ` Dave Stevenson
2020-12-15 11:04     ` Dave Stevenson

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