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From: Giulio Benetti <giulio.benetti@micronovasrl.com>
To: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: David Airlie <airlied@linux.ie>, Chen-Yu Tsai <wens@csie.org>,
	dri-devel@lists.freedesktop.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org,
	Giulio Benetti <giulio.benetti@micronovasrl.com>
Subject: [PATCH v3 2/2] drm/sun4i: tcon: prevent tcon->panel dereference if NULL
Date: Fri,  5 Oct 2018 23:59:51 +0200	[thread overview]
Message-ID: <20181005215951.99003-2-giulio.benetti@micronovasrl.com> (raw)
In-Reply-To: <20181005215951.99003-1-giulio.benetti@micronovasrl.com>

If tcon->panel pointer is NULL, trying to dereference from it
(i.e. tcon->panel->connector) will cause a null pointer dereference.

Add tcon->panel null pointer check before calling
sun4i_tcon0_mode_set_dithering().

Signed-off-by: Giulio Benetti <giulio.benetti@micronovasrl.com>
Fixes: f11adcecbd5f ("drm/sun4i: tcon: Add dithering support for
                      RGB565/RGB666 LCD panels")
Reviewed-by: Chen-Yu Tsai <wens@csie.org>
---
Changes V1->V2:
* None

Changes V2->V3:
* Rewrite commit log

 drivers/gpu/drm/sun4i/sun4i_tcon.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
index e4b3bd0307ef..f949287d926c 100644
--- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
+++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
@@ -491,7 +491,8 @@ static void sun4i_tcon0_mode_set_rgb(struct sun4i_tcon *tcon,
 	sun4i_tcon0_mode_set_common(tcon, mode);
 
 	/* Set dithering if needed */
-	sun4i_tcon0_mode_set_dithering(tcon, tcon->panel->connector);
+	if (tcon->panel)
+		sun4i_tcon0_mode_set_dithering(tcon, tcon->panel->connector);
 
 	/* Adjust clock delay */
 	clk_delay = sun4i_tcon_get_clk_delay(mode, 0);
-- 
2.17.1


WARNING: multiple messages have this Message-ID (diff)
From: giulio.benetti@micronovasrl.com (Giulio Benetti)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v3 2/2] drm/sun4i: tcon: prevent tcon->panel dereference if NULL
Date: Fri,  5 Oct 2018 23:59:51 +0200	[thread overview]
Message-ID: <20181005215951.99003-2-giulio.benetti@micronovasrl.com> (raw)
In-Reply-To: <20181005215951.99003-1-giulio.benetti@micronovasrl.com>

If tcon->panel pointer is NULL, trying to dereference from it
(i.e. tcon->panel->connector) will cause a null pointer dereference.

Add tcon->panel null pointer check before calling
sun4i_tcon0_mode_set_dithering().

Signed-off-by: Giulio Benetti <giulio.benetti@micronovasrl.com>
Fixes: f11adcecbd5f ("drm/sun4i: tcon: Add dithering support for
                      RGB565/RGB666 LCD panels")
Reviewed-by: Chen-Yu Tsai <wens@csie.org>
---
Changes V1->V2:
* None

Changes V2->V3:
* Rewrite commit log

 drivers/gpu/drm/sun4i/sun4i_tcon.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
index e4b3bd0307ef..f949287d926c 100644
--- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
+++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
@@ -491,7 +491,8 @@ static void sun4i_tcon0_mode_set_rgb(struct sun4i_tcon *tcon,
 	sun4i_tcon0_mode_set_common(tcon, mode);
 
 	/* Set dithering if needed */
-	sun4i_tcon0_mode_set_dithering(tcon, tcon->panel->connector);
+	if (tcon->panel)
+		sun4i_tcon0_mode_set_dithering(tcon, tcon->panel->connector);
 
 	/* Adjust clock delay */
 	clk_delay = sun4i_tcon_get_clk_delay(mode, 0);
-- 
2.17.1

  reply	other threads:[~2018-10-05 22:00 UTC|newest]

Thread overview: 50+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-10-01  9:36 [bug report] drm/sun4i: Handle DRM_BUS_FLAG_PIXDATA_*EDGE checking if panel is used Dan Carpenter
2018-10-02 13:26 ` Giulio Benetti
2018-10-02 14:12   ` Giulio Benetti
2018-10-02 20:40     ` Giulio Benetti
2018-10-11  7:16   ` Dan Carpenter
2018-10-11 21:36     ` Giulio Benetti
2018-10-02 20:48 ` [PATCH 1/2] drm/sun4i: tcon: fix check of tcon->panel null pointer Giulio Benetti
2018-10-02 20:48   ` Giulio Benetti
2018-10-02 20:49   ` [PATCH 2/2] drm/sun4i: tcon: prevent tcon->panel dereference if null Giulio Benetti
2018-10-02 20:49     ` Giulio Benetti
2018-10-02 21:59 ` [PATCH 1/2] drm/sun4i: tcon: fix check of tcon->panel null pointer Giulio Benetti
2018-10-02 21:59   ` Giulio Benetti
2018-10-02 21:59   ` Giulio Benetti
2018-10-02 21:59   ` [PATCH 2/2] drm/sun4i: tcon: prevent tcon->panel dereference if null Giulio Benetti
2018-10-02 21:59     ` Giulio Benetti
2018-10-03  7:34     ` Chen-Yu Tsai
2018-10-03  7:34       ` Chen-Yu Tsai
2018-10-02 22:00   ` [PATCH 1/2] drm/sun4i: tcon: fix check of tcon->panel null pointer Giulio Benetti
2018-10-02 22:00     ` Giulio Benetti
2018-10-02 22:00     ` Giulio Benetti
2018-10-03  9:43   ` Chen-Yu Tsai
2018-10-03  9:43     ` Chen-Yu Tsai
2018-10-03 12:13     ` Giulio Benetti
2018-10-03 12:13       ` Giulio Benetti
2018-10-03 14:24       ` [PATCH v2 " Giulio Benetti
2018-10-03 14:24         ` Giulio Benetti
2018-10-03 14:24         ` [PATCH v2 2/2] drm/sun4i: tcon: prevent tcon->panel dereference if null Giulio Benetti
2018-10-03 14:24           ` Giulio Benetti
2018-10-03 14:24           ` Giulio Benetti
2018-10-04 19:56           ` Maxime Ripard
2018-10-04 19:56             ` Maxime Ripard
2018-10-04 19:56             ` Maxime Ripard
2018-10-05 21:38             ` Giulio Benetti
2018-10-05 21:38               ` Giulio Benetti
2018-10-05 21:59             ` [PATCH v3 1/2] drm/sun4i: tcon: fix check of tcon->panel null pointer Giulio Benetti
2018-10-05 21:59               ` Giulio Benetti
2018-10-05 21:59               ` Giulio Benetti
2018-10-05 21:59               ` Giulio Benetti [this message]
2018-10-05 21:59                 ` [PATCH v3 2/2] drm/sun4i: tcon: prevent tcon->panel dereference if NULL Giulio Benetti
2018-10-08  9:21                 ` Maxime Ripard
2018-10-08  9:21                   ` Maxime Ripard
2018-10-12 10:03                   ` Chen-Yu Tsai
2018-10-12 10:03                     ` Chen-Yu Tsai
2018-11-05 13:23                   ` Icenowy Zheng
2018-11-05 13:23                     ` Icenowy Zheng
2018-11-06 15:57                     ` Maxime Ripard
2018-11-06 15:57                       ` Maxime Ripard
2018-10-04 19:54         ` [PATCH v2 1/2] drm/sun4i: tcon: fix check of tcon->panel null pointer Maxime Ripard
2018-10-04 19:54           ` Maxime Ripard
2018-10-04 19:54           ` Maxime Ripard

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