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=-8.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT 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 DA662C43387 for ; Mon, 24 Dec 2018 10:53:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A305C2173C for ; Mon, 24 Dec 2018 10:53:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="a6Pb/AwF" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725806AbeLXKxX (ORCPT ); Mon, 24 Dec 2018 05:53:23 -0500 Received: from mail-ed1-f66.google.com ([209.85.208.66]:45659 "EHLO mail-ed1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725385AbeLXKxX (ORCPT ); Mon, 24 Dec 2018 05:53:23 -0500 Received: by mail-ed1-f66.google.com with SMTP id d39so9786539edb.12 for ; Mon, 24 Dec 2018 02:53:22 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=sender:date:from:to:cc:subject:message-id:mail-followup-to :references:mime-version:content-disposition:in-reply-to:user-agent; bh=79REX5h0sIpW7jzF4+vTzE6KwVFoWwLAdDLIOrCt8sY=; b=a6Pb/AwFAHUuFsS9h+qp/J1tzkxsDT6/Wbq0jZ0SMvIyw2ZQ/WCpXzcgqnpJzFYvL7 CYVW+akkTawSEqegFAaNEDS3E/3HmdjSn3QQ36bT68d6HuqCM7NTZipxglKDf+FJxEXa 7uM+LEbUEfIz8iEgqcgTfgHi2yyNeypHkYsFE= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :mail-followup-to:references:mime-version:content-disposition :in-reply-to:user-agent; bh=79REX5h0sIpW7jzF4+vTzE6KwVFoWwLAdDLIOrCt8sY=; b=lNl9tVm1VFjiTMxOxtgO/w1YZ62g41aGu84i/74R5/O0BDlsvISvJWzYnTJSkedShd gCttbgxOemK5dVJ4XYSiKtCg+KeXfRFbxp7qQb8LszfyQK3TMVfZfEVL1932sNUt8wG3 8m3oIjKHQCIne/MxctizE6OswjMDFofxnUQ27l9oUqJ/oOY7AsBjf5BO46CiUbeLu/cn IdlKh0VsPGxcCcfjWf5q4a2mvRxGV+WeTv1VT1da6nNURhMsXHQt19z0b6BnEDDPrz+x OtbTOOj39E0biYQ1BuX/P6dSHhvHPavrad4X2Pi9ODt+Ka1VcUSHBl2nuY/mdbE+w7Dq al3g== X-Gm-Message-State: AA+aEWY2DuVRgUlbtuE8+ZvjfJCMV7BoTCSIhCKPrmPNMIQZqZbACrrM qli09RZglNN/PiUqe3PnBVN77w== X-Google-Smtp-Source: AFSGD/Uq+QyjQoGVIKT1/F+QjM7F7+GcH/01pWeBrVEY/4l8zv329SCrHzcXvLnCEgIk1qlun/fgog== X-Received: by 2002:a17:906:5118:: with SMTP id w24-v6mr8588068ejk.215.1545648801711; Mon, 24 Dec 2018 02:53:21 -0800 (PST) Received: from dvetter-linux.ger.corp.intel.com ([194.230.159.220]) by smtp.gmail.com with ESMTPSA id t15-v6sm4712025ejt.0.2018.12.24.02.53.20 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 24 Dec 2018 02:53:20 -0800 (PST) Date: Mon, 24 Dec 2018 11:53:18 +0100 From: Daniel Vetter To: Colin King Cc: Rob Clark , Maarten Lankhorst , Maxime Ripard , Sean Paul , David Airlie , Daniel Vetter , dri-devel@lists.freedesktop.org, kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH][next] drm: fix null pointer dereference on null state pointer Message-ID: <20181224105317.GC30772@dvetter-linux.ger.corp.intel.com> Mail-Followup-To: Colin King , Rob Clark , Maarten Lankhorst , Maxime Ripard , Sean Paul , David Airlie , dri-devel@lists.freedesktop.org, kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org References: <20181222130046.14083-1-colin.king@canonical.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181222130046.14083-1-colin.king@canonical.com> X-Operating-System: Linux dvetter-linux.ger.corp.intel.com 4.18.17-200.fc28.x86_64 User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Dec 22, 2018 at 01:00:46PM +0000, Colin King wrote: > 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 Looks correct to me, merged into drm-misc-next-fixes for 4.21. Thanks, Daniel > --- > 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 > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch