From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=3.0 tests=DATE_IN_PAST_03_06, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 71DA7C43387 for ; Sat, 22 Dec 2018 18:31:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 44DC321917 for ; Sat, 22 Dec 2018 18:31:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392074AbeLVSbV (ORCPT ); Sat, 22 Dec 2018 13:31:21 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:42517 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391926AbeLVSbI (ORCPT ); Sat, 22 Dec 2018 13:31:08 -0500 Received: from 1.general.cking.uk.vpn ([10.172.193.212] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.76) (envelope-from ) id 1gagta-0000Uj-Et; Sat, 22 Dec 2018 13:00:46 +0000 From: Colin King To: Rob Clark , Maarten Lankhorst , Maxime Ripard , Sean Paul , David Airlie , Daniel Vetter , dri-devel@lists.freedesktop.org Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH][next] drm: fix null pointer dereference on null state pointer Date: Sat, 22 Dec 2018 13:00:46 +0000 Message-Id: <20181222130046.14083-1-colin.king@canonical.com> X-Mailer: git-send-email 2.19.1 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Colin Ian King In the case where state cannot be allocated, the current exit path via label 'out' will dereference the null state pointer when calling drm_atomic_state_put. Fix this by adding a new error exit label and jumping to this to avoid the drm_atomic_state_put. Detected by CoverityScan, CID#1476034 ("Dereference after null check") Fixes: b9fc5e01d1ce ("drm: Add helper to implement legacy dirtyfb") Signed-off-by: Colin Ian King --- drivers/gpu/drm/drm_damage_helper.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/drm_damage_helper.c b/drivers/gpu/drm/drm_damage_helper.c index d2a1c7372f36..31032407254d 100644 --- a/drivers/gpu/drm/drm_damage_helper.c +++ b/drivers/gpu/drm/drm_damage_helper.c @@ -178,7 +178,7 @@ int drm_atomic_helper_dirtyfb(struct drm_framebuffer *fb, state = drm_atomic_state_alloc(fb->dev); if (!state) { ret = -ENOMEM; - goto out; + goto out_drop_locks; } state->acquire_ctx = &ctx; @@ -238,6 +238,7 @@ int drm_atomic_helper_dirtyfb(struct drm_framebuffer *fb, kfree(rects); drm_atomic_state_put(state); +out_drop_locks: drm_modeset_drop_locks(&ctx); drm_modeset_acquire_fini(&ctx); -- 2.19.1