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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 A8CEEC3F68F for ; Tue, 7 Jan 2020 20:56:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7CEBA2087F for ; Tue, 7 Jan 2020 20:56:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578430576; bh=hgVZmdjmoaFFQFb3gUYdr4Lz0gk+Zd7/7MRIZfKlTOA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=UoSm9zIkL4uRqHsDPZLwNN79G4yGhRkSCnSRdfKkd9shA5Tc5RMPxzRov9L1NlSHm xso3WsEi2HIOBnN3YB283hMGvtIvS6pS89mErrNmaw5I3VCsZbi8NomhreODjcfCyb /aTcHKmoCH7/RVk3d8d/GifWGZmeb/VQrHG6oLFA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726955AbgAGU4Q (ORCPT ); Tue, 7 Jan 2020 15:56:16 -0500 Received: from mail.kernel.org ([198.145.29.99]:51248 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726142AbgAGU4P (ORCPT ); Tue, 7 Jan 2020 15:56:15 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3902B2081E; Tue, 7 Jan 2020 20:56:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578430574; bh=hgVZmdjmoaFFQFb3gUYdr4Lz0gk+Zd7/7MRIZfKlTOA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nD+8Cj+mqJo7TX2zjtB0FNVKIhkG/30NlfStQq/zwhjL5F01a/dp5xoJbKU72mYKz z1Ac7mL6RZjFjIouBK9w2xiFovXdHM46vXm1k7UlftnwONVW/A1cgeOo0xqn8m1gWV Xc5+QPPZOWxyFKBJzAwaC5jDnYZ1rI3FaotTGVaQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Stephan Gerhold , Linus Walleij , Sasha Levin Subject: [PATCH 5.4 001/191] drm/mcde: dsi: Fix invalid pointer dereference if panel cannot be found Date: Tue, 7 Jan 2020 21:52:01 +0100 Message-Id: <20200107205333.084061484@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200107205332.984228665@linuxfoundation.org> References: <20200107205332.984228665@linuxfoundation.org> User-Agent: quilt/0.66 X-stable: review X-Patchwork-Hint: ignore 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: Stephan Gerhold [ Upstream commit c131280c03bd1c225c2e64e9ef75873ffca3d96e ] The "panel" pointer is not reset to NULL if of_drm_find_panel() returns an error. Therefore we later assume that a panel was found, and try to dereference the error pointer, resulting in: mcde-dsi a0351000.dsi: failed to find panel try bridge (4294966779) Unable to handle kernel paging request at virtual address fffffe03 PC is at drm_panel_bridge_add.part.0+0x10/0x5c LR is at mcde_dsi_bind+0x120/0x464 ... Reset "panel" to NULL to avoid this problem. Also change the format string of the error to %ld to print the negative errors correctly. The crash above then becomes: mcde-dsi a0351000.dsi: failed to find panel try bridge (-517) mcde-dsi a0351000.dsi: no panel or bridge ... Fixes: 5fc537bfd000 ("drm/mcde: Add new driver for ST-Ericsson MCDE") Signed-off-by: Stephan Gerhold Signed-off-by: Linus Walleij Link: https://patchwork.freedesktop.org/patch/msgid/20191118130252.170324-1-stephan@gerhold.net Signed-off-by: Sasha Levin --- drivers/gpu/drm/mcde/mcde_dsi.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/mcde/mcde_dsi.c b/drivers/gpu/drm/mcde/mcde_dsi.c index f9c9e32b299c..35bb825d1918 100644 --- a/drivers/gpu/drm/mcde/mcde_dsi.c +++ b/drivers/gpu/drm/mcde/mcde_dsi.c @@ -935,11 +935,13 @@ static int mcde_dsi_bind(struct device *dev, struct device *master, for_each_available_child_of_node(dev->of_node, child) { panel = of_drm_find_panel(child); if (IS_ERR(panel)) { - dev_err(dev, "failed to find panel try bridge (%lu)\n", + dev_err(dev, "failed to find panel try bridge (%ld)\n", PTR_ERR(panel)); + panel = NULL; + bridge = of_drm_find_bridge(child); if (IS_ERR(bridge)) { - dev_err(dev, "failed to find bridge (%lu)\n", + dev_err(dev, "failed to find bridge (%ld)\n", PTR_ERR(bridge)); return PTR_ERR(bridge); } -- 2.20.1