From patchwork Thu Aug 4 12:41:23 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zheyu Ma X-Patchwork-Id: 595409 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 DD482C19F2D for ; Thu, 4 Aug 2022 12:41:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239344AbiHDMlt (ORCPT ); Thu, 4 Aug 2022 08:41:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58606 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239368AbiHDMlr (ORCPT ); Thu, 4 Aug 2022 08:41:47 -0400 Received: from mail-pg1-x535.google.com (mail-pg1-x535.google.com [IPv6:2607:f8b0:4864:20::535]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5AFCB3205A; Thu, 4 Aug 2022 05:41:45 -0700 (PDT) Received: by mail-pg1-x535.google.com with SMTP id 12so17863333pga.1; Thu, 04 Aug 2022 05:41:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc; bh=w0Xxsd10rxzXzo6/5gdWcIy61xCxC4G1bz1u1E9fXCo=; b=qD8j7MqqhHWzCEXuJN+GpeSzUdlAxRyaiur92DU6at98u5tgv2exchm9KnIJRPGGwS 4RgMLhbFh/yr8Q5O4ECnkUGj9S8gVPjiXPm2LAFsx62EZjdxCo/OrIO5X5UEUWZsK5PU UJFOkziuTiJVtruzn+BZy2AXNBM9tOueP9AeUKB8Os84d2OHraomImWx0uk3mxj4ocS9 yt97Dn5UzB1sUM9GM90TBP/DX0MFg4Jas3MDnu477/0yYH7Q8QAuxZGpZ0l1JAg0BiAr f1sP+x3t5jzGDNAbbDywp0l0mt82aC4dm5lR37ou1KVyg69+j4Q+f6p4AxwrxFDJ3bHw 8OLQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc; bh=w0Xxsd10rxzXzo6/5gdWcIy61xCxC4G1bz1u1E9fXCo=; b=WDF3klEnKUm4HXOPV8XktOXTkjLHfohs84MJffvV75wcTfElTMfDSMzmr6lvoaMads 2zO7QWfg/r3e8wldVIrffJO+yq9pnL6ogrKneRll71mbliS2i/ydeJRW4YVdvzZtzNQl oyiKSZDTf7hzwNk4oWJpQwvYnzJSwVVKzfGFgYZCz/u7lKlLRAGhACV4Q+0/r8gGODsR Eu0aQDd8QQfa+97uReqZ3c26iLVTNJLsTXc2+O+9TQYCnJYZR/47XknSzHDUQIWREmCS Vl1pJsng5ccsF2LHKrsXkblWVH8p6NnCxjHN1BXBU8dRyd4x0j9NmvvTGvB6SfoPqtZC Yo7A== X-Gm-Message-State: ACgBeo0V4BJvoK5TdxcVQcKOAN6Vj5dQqL57wn49Lo6fJMFrU874QFp3 R86L1JCA0wLVjL58u1Srpw== X-Google-Smtp-Source: AA6agR5DWlGw0W1xZXujx2KGDv9sHfvTIt+iTdErPfZLMXgRlBBtcYlNDb72wX2TK2CqsJhy7Jwogw== X-Received: by 2002:a63:1658:0:b0:41a:4118:f4b9 with SMTP id 24-20020a631658000000b0041a4118f4b9mr1497090pgw.153.1659616904598; Thu, 04 Aug 2022 05:41:44 -0700 (PDT) Received: from localhost.localdomain ([166.111.133.51]) by smtp.gmail.com with ESMTPSA id i8-20020a63bf48000000b0041b672e93c2sm1070769pgo.17.2022.08.04.05.41.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 04 Aug 2022 05:41:44 -0700 (PDT) From: Zheyu Ma To: deller@gmx.de, adaplas@gmail.com, santiago@crfreenet.org, akpm@linux-foundation.org Cc: linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Zheyu Ma Subject: [PATCH 1/3] video: fbdev: vt8623fb: Check the size of screen before memset_io() Date: Thu, 4 Aug 2022 20:41:23 +0800 Message-Id: <20220804124125.3506755-2-zheyuma97@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220804124125.3506755-1-zheyuma97@gmail.com> References: <20220804124125.3506755-1-zheyuma97@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org In the function vt8623fb_set_par(), the value of 'screen_size' is calculated by the user input. If the user provides the improper value, the value of 'screen_size' may larger than 'info->screen_size', which may cause the following bug: [ 583.339036] BUG: unable to handle page fault for address: ffffc90005000000 [ 583.339049] #PF: supervisor write access in kernel mode [ 583.339052] #PF: error_code(0x0002) - not-present page [ 583.339074] RIP: 0010:memset_orig+0x33/0xb0 [ 583.339110] Call Trace: [ 583.339118] vt8623fb_set_par+0x11cd/0x21e0 [ 583.339146] fb_set_var+0x604/0xeb0 [ 583.339181] do_fb_ioctl+0x234/0x670 [ 583.339209] fb_ioctl+0xdd/0x130 Fix the this by checking the value of 'screen_size' before memset_io(). Fixes: 558b7bd86c32 ("vt8623fb: new framebuffer driver for VIA VT8623") Signed-off-by: Zheyu Ma --- drivers/video/fbdev/vt8623fb.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/video/fbdev/vt8623fb.c b/drivers/video/fbdev/vt8623fb.c index a92a8c670cf0..4274c6efb249 100644 --- a/drivers/video/fbdev/vt8623fb.c +++ b/drivers/video/fbdev/vt8623fb.c @@ -507,6 +507,8 @@ static int vt8623fb_set_par(struct fb_info *info) (info->var.vmode & FB_VMODE_DOUBLE) ? 2 : 1, 1, 1, info->node); + if (screen_size > info->screen_size) + screen_size = info->screen_size; memset_io(info->screen_base, 0x00, screen_size); /* Device and screen back on */