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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C81A3CCA48E for ; Tue, 7 Jun 2022 17:36:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347659AbiFGRfg (ORCPT ); Tue, 7 Jun 2022 13:35:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39620 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346415AbiFGR1u (ORCPT ); Tue, 7 Jun 2022 13:27:50 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1BE56113FB7; Tue, 7 Jun 2022 10:24:21 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id AD050B822AF; Tue, 7 Jun 2022 17:24:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 18F99C385A5; Tue, 7 Jun 2022 17:24:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1654622658; bh=c7Bux8gORtIUyKX+nEOcBp7LJR8TG4CjpwtkMuws2Hw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ltSIyk5d6fmZhFWcIhp65a+cYH4IGw21s12tekMKl0hZok6DZBolKyuY2RxAelhpj Jf6w4J3NS0VGmLcI96Iwl/RPF7g72ChhPFGswbwZGHvqljea615J34nGrM+RLGEoWB 5d4yZ2A+8gNPjJpJlr9HZae9mLG/8JvhubNRDNro= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Zhou Qingyang , Liviu Dudau , Sasha Levin Subject: [PATCH 5.10 138/452] drm/komeda: Fix an undefined behavior bug in komeda_plane_add() Date: Tue, 7 Jun 2022 18:59:55 +0200 Message-Id: <20220607164912.671974322@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220607164908.521895282@linuxfoundation.org> References: <20220607164908.521895282@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Zhou Qingyang [ Upstream commit f5e284bb74ab296f98122673c7ecd22028b2c200 ] In komeda_plane_add(), komeda_get_layer_fourcc_list() is assigned to formats and used in drm_universal_plane_init(). drm_universal_plane_init() passes formats to __drm_universal_plane_init(). __drm_universal_plane_init() further passes formats to memcpy() as src parameter, which could lead to an undefined behavior bug on failure of komeda_get_layer_fourcc_list(). Fix this bug by adding a check of formats. This bug was found by a static analyzer. The analysis employs differential checking to identify inconsistent security operations (e.g., checks or kfrees) between two code paths and confirms that the inconsistent operations are not recovered in the current function or the callers, so they constitute bugs. Note that, as a bug found by static analysis, it can be a false positive or hard to trigger. Multiple researchers have cross-reviewed the bug. Builds with CONFIG_DRM_KOMEDA=m show no new warnings, and our static analyzer no longer warns about this code. Fixes: 61f1c4a8ab75 ("drm/komeda: Attach komeda_dev to DRM-KMS") Signed-off-by: Zhou Qingyang Signed-off-by: Liviu Dudau Link: https://lore.kernel.org/dri-devel/20211201033704.32054-1-zhou1615@umn.edu Signed-off-by: Sasha Levin --- drivers/gpu/drm/arm/display/komeda/komeda_plane.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_plane.c b/drivers/gpu/drm/arm/display/komeda/komeda_plane.c index a5f57b38d193..bc3f42e915e9 100644 --- a/drivers/gpu/drm/arm/display/komeda/komeda_plane.c +++ b/drivers/gpu/drm/arm/display/komeda/komeda_plane.c @@ -264,6 +264,10 @@ static int komeda_plane_add(struct komeda_kms_dev *kms, formats = komeda_get_layer_fourcc_list(&mdev->fmt_tbl, layer->layer_type, &n_formats); + if (!formats) { + kfree(kplane); + return -ENOMEM; + } err = drm_universal_plane_init(&kms->base, plane, get_possible_crtcs(kms, c->pipeline), -- 2.35.1