Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752939AbdLDVyc (ORCPT ); Mon, 4 Dec 2017 16:54:32 -0500 Received: from gateway20.websitewelcome.com ([192.185.65.13]:39911 "EHLO gateway20.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752687AbdLDVy2 (ORCPT ); Mon, 4 Dec 2017 16:54:28 -0500 Date: Mon, 4 Dec 2017 15:54:18 -0600 From: "Gustavo A. R. Silva" To: VMware Graphics , Sinclair Yeh , Thomas Hellstrom , David Airlie Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH] drm/vmwgfx_kms: Fix potential NULL pointer dereference Message-ID: <20171204215418.GA23874@embeddedor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.24 (2015-08-30) X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - gator4166.hostgator.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - embeddedor.com X-BWhitelist: no X-Source-IP: 189.145.56.156 X-Source-L: No X-Exim-ID: 1eLyh1-003NKm-0z X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.145.56.156]:57744 X-Source-Auth: garsilva@embeddedor.com X-Email-Count: 6 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1145 Lines: 31 crtc_state is being null checked in a previous code block, which implies that such pointer might be null. crtc_state is dereferenced in drm_atomic_helper_check_plane_state, hence there is a potential null pointer dereference. Fix this by warning-on and returning -EINVAL in case crtc_state is null. Addresses-Coverity-ID: 1462412 ("Dereference after null check") Fixes: a01cb8ba3f62 ("drm: Move drm_plane_helper_check_state() into drm_atomic_helper.c") Signed-off-by: Gustavo A. R. Silva --- drivers/gpu/drm/vmwgfx/vmwgfx_kms.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c index a2a93d7..72c3b290 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c @@ -454,6 +454,9 @@ int vmw_du_primary_plane_atomic_check(struct drm_plane *plane, clip.y2 = crtc_state->adjusted_mode.vdisplay; } + if (WARN_ON(!crtc_state)) + return -EINVAL; + ret = drm_atomic_helper_check_plane_state(state, crtc_state, &clip, DRM_PLANE_HELPER_NO_SCALING, DRM_PLANE_HELPER_NO_SCALING, -- 2.7.4