From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jingoo Han Subject: Re: [PATCH] drm/exynos: dpi: Fix NULL pointer dereference with legacy bindings Date: Wed, 18 Jun 2014 10:07:48 +0900 Message-ID: <004d01cf8a91$b8b849d0$2a28dd70$%han@samsung.com> References: <1402433877-10867-1-git-send-email-tomasz.figa@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: In-reply-to: <1402433877-10867-1-git-send-email-tomasz.figa@gmail.com> Content-language: ko Sender: linux-samsung-soc-owner@vger.kernel.org To: 'Tomasz Figa' , 'Inki Dae' Cc: dri-devel@lists.freedesktop.org, linux-samsung-soc@vger.kernel.org, 'Andrzej Hajda' , 'Jingoo Han' List-Id: dri-devel@lists.freedesktop.org On Wednesday, June 11, 2014 5:58 AM, Tomasz Figa wrote: > > If there is no panel node in DT and instead display timings are provided > directly in FIMD node, there is no panel object created and ctx->panel > becomes NULL. However during Exynos DRM initialization > drm_helper_hpd_irq_event() is called, which in turns calls > exynos_dpi_detect(), which dereferences ctx->panel without a check, > causing a NULL pointer derefrence. > > This patch fixes the issue by adding necessary NULL pointer check. > > Signed-off-by: Tomasz Figa (+cc Inki Dae) Reviewed-by: Jingoo Han Best regards, Jingoo Han > --- > drivers/gpu/drm/exynos/exynos_drm_dpi.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/exynos/exynos_drm_dpi.c b/drivers/gpu/drm/exynos/exynos_drm_dpi.c > index f1b8587..f44bd90 100644 > --- a/drivers/gpu/drm/exynos/exynos_drm_dpi.c > +++ b/drivers/gpu/drm/exynos/exynos_drm_dpi.c > @@ -40,7 +40,7 @@ exynos_dpi_detect(struct drm_connector *connector, bool force) > { > struct exynos_dpi *ctx = connector_to_dpi(connector); > > - if (!ctx->panel->connector) > + if (ctx->panel && !ctx->panel->connector) > drm_panel_attach(ctx->panel, &ctx->connector); > > return connector_status_connected; > --