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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS 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 3E652C00449 for ; Fri, 5 Oct 2018 21:38:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 008B1213A2 for ; Fri, 5 Oct 2018 21:38:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=micronovasrl.com header.i=@micronovasrl.com header.b="cn1MkxsC" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 008B1213A2 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=micronovasrl.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727317AbeJFEio (ORCPT ); Sat, 6 Oct 2018 00:38:44 -0400 Received: from mail.micronovasrl.com ([212.103.203.10]:44646 "EHLO mail.micronovasrl.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725928AbeJFEio (ORCPT ); Sat, 6 Oct 2018 00:38:44 -0400 Received: from mail.micronovasrl.com (mail.micronovasrl.com [127.0.0.1]) by mail.micronovasrl.com (Postfix) with ESMTP id CEA9CB007A0 for ; Fri, 5 Oct 2018 23:38:07 +0200 (CEST) Authentication-Results: mail.micronovasrl.com (amavisd-new); dkim=pass reason="pass (just generated, assumed good)" header.d=micronovasrl.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=micronovasrl.com; h=content-transfer-encoding:content-language:content-type :content-type:in-reply-to:mime-version:user-agent:date:date :message-id:from:from:references:to:subject:subject; s=dkim; t= 1538775487; x=1539639488; bh=O7OP41IKVVl16KvfKVxbCQMXgQ1YNm+KcrC iK55JFH8=; b=cn1MkxsCywXDOSBAbgsR97Zrho1qc/Sorc3lCgTLmptVjvSiTZX hscTcIfwZnIS81WJuHCtCy/mvtat3JSE+oD2nVviUSYDIefamlbp1C+N2VSu/RiK Rl4yK3tQyBYhETu9tUM81Mr8GiA0ComAOGbgOnQ1DTambYdQRLoby1ik= X-Virus-Scanned: Debian amavisd-new at mail.micronovasrl.com Received: from mail.micronovasrl.com ([127.0.0.1]) by mail.micronovasrl.com (mail.micronovasrl.com [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id U_2P60P5aOxe for ; Fri, 5 Oct 2018 23:38:07 +0200 (CEST) Received: from [192.168.123.60] (unknown [192.168.123.60]) by mail.micronovasrl.com (Postfix) with ESMTPSA id DEA9EB003B2; Fri, 5 Oct 2018 23:38:06 +0200 (CEST) Subject: Re: [PATCH v2 2/2] drm/sun4i: tcon: prevent tcon->panel dereference if null To: Maxime Ripard Cc: David Airlie , Chen-Yu Tsai , linux-arm-kernel@lists.infradead.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org References: <9a545739-eed5-7af1-3b75-108bdd3427a2@micronovasrl.com> <20181003142458.33120-1-giulio.benetti@micronovasrl.com> <20181003142458.33120-2-giulio.benetti@micronovasrl.com> <20181004195605.txvbkshvxklyzxyb@flea> From: Giulio Benetti Message-ID: <5c45b263-e310-82af-ffb3-85eac93622d5@micronovasrl.com> Date: Fri, 5 Oct 2018 23:38:06 +0200 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 MIME-Version: 1.0 In-Reply-To: <20181004195605.txvbkshvxklyzxyb@flea> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: it Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Il 04/10/2018 21:56, Maxime Ripard ha scritto: > On Wed, Oct 03, 2018 at 04:24:58PM +0200, Giulio Benetti wrote: >> If using tcon with VGA, > > We don't have support for VGA at the moment. Or are you talking about > using a VGA bridge? You're right, in general VGA is not the point. tcon->panel is retrieved by drm_of_find_panel_or_bridge() and panel can be present or not. >> tcon->panel will be null(0), this will cause segmentation fault when >> trying to dereference tcon->panel->connector. > > It's not a segmentation fault, but a null pointer dereference. And > that case will also happen with bridges. Right. Going to improve/rewrite commit logs and submit v2 patchset. Thanks for reviewing. Best regards -- Giulio Benetti CTO MICRONOVA SRL Sede: Via A. Niedda 3 - 35010 Vigonza (PD) Tel. 049/8931563 - Fax 049/8931346 Cod.Fiscale - P.IVA 02663420285 Capitale Sociale € 26.000 i.v. Iscritta al Reg. Imprese di Padova N. 02663420285 Numero R.E.A. 258642 From mboxrd@z Thu Jan 1 00:00:00 1970 From: giulio.benetti@micronovasrl.com (Giulio Benetti) Date: Fri, 5 Oct 2018 23:38:06 +0200 Subject: [PATCH v2 2/2] drm/sun4i: tcon: prevent tcon->panel dereference if null In-Reply-To: <20181004195605.txvbkshvxklyzxyb@flea> References: <9a545739-eed5-7af1-3b75-108bdd3427a2@micronovasrl.com> <20181003142458.33120-1-giulio.benetti@micronovasrl.com> <20181003142458.33120-2-giulio.benetti@micronovasrl.com> <20181004195605.txvbkshvxklyzxyb@flea> Message-ID: <5c45b263-e310-82af-ffb3-85eac93622d5@micronovasrl.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi, Il 04/10/2018 21:56, Maxime Ripard ha scritto: > On Wed, Oct 03, 2018 at 04:24:58PM +0200, Giulio Benetti wrote: >> If using tcon with VGA, > > We don't have support for VGA at the moment. Or are you talking about > using a VGA bridge? You're right, in general VGA is not the point. tcon->panel is retrieved by drm_of_find_panel_or_bridge() and panel can be present or not. >> tcon->panel will be null(0), this will cause segmentation fault when >> trying to dereference tcon->panel->connector. > > It's not a segmentation fault, but a null pointer dereference. And > that case will also happen with bridges. Right. Going to improve/rewrite commit logs and submit v2 patchset. Thanks for reviewing. Best regards -- Giulio Benetti CTO MICRONOVA SRL Sede: Via A. Niedda 3 - 35010 Vigonza (PD) Tel. 049/8931563 - Fax 049/8931346 Cod.Fiscale - P.IVA 02663420285 Capitale Sociale ? 26.000 i.v. Iscritta al Reg. Imprese di Padova N. 02663420285 Numero R.E.A. 258642