From mboxrd@z Thu Jan 1 00:00:00 1970 From: giulio.benetti@micronovasrl.com (Giulio Benetti) Date: Fri, 5 Oct 2018 23:59:51 +0200 Subject: [PATCH v3 2/2] drm/sun4i: tcon: prevent tcon->panel dereference if NULL In-Reply-To: <20181005215951.99003-1-giulio.benetti@micronovasrl.com> References: <20181004195605.txvbkshvxklyzxyb@flea> <20181005215951.99003-1-giulio.benetti@micronovasrl.com> Message-ID: <20181005215951.99003-2-giulio.benetti@micronovasrl.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 Fixes: f11adcecbd5f ("drm/sun4i: tcon: Add dithering support for RGB565/RGB666 LCD panels") Reviewed-by: Chen-Yu Tsai --- 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