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 900BCC43334 for ; Sat, 25 Jun 2022 22:34:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233529AbiFYWeP (ORCPT ); Sat, 25 Jun 2022 18:34:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51498 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230246AbiFYWeO (ORCPT ); Sat, 25 Jun 2022 18:34:14 -0400 Received: from mail-ed1-x52f.google.com (mail-ed1-x52f.google.com [IPv6:2a00:1450:4864:20::52f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B17BDBE31 for ; Sat, 25 Jun 2022 15:34:13 -0700 (PDT) Received: by mail-ed1-x52f.google.com with SMTP id z19so8059428edb.11 for ; Sat, 25 Jun 2022 15:34:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=L4B2P55ZFiYVCJ5DZUrHpNuoCg7yfMFjsA7dxqf94Ng=; b=CqNHYBzkAe+4uRJq+tgr9R+4iN85PvgiXpvwNIYaGcGIXorRGxtHVNIGaK99IVdvHT pUVMoPtPZq21KAi119Y47YaNA7tifutRngx+CWoVeN99hg/akvJEXvPC0wNJ41pEdVG9 0ynPpYCeziouXY4GdLbb6tymzQXgUcd37bbyY= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=L4B2P55ZFiYVCJ5DZUrHpNuoCg7yfMFjsA7dxqf94Ng=; b=suJf6A8ghZBMr3PbORqgSBzAz1ifUepaKjyzcihyZT8ECs6c88mnS3IxBq6aBSjE28 iRYl7EZ8t+iB4t+jdXJp+uP8eFjUfn7asSy2hEpRYRmvE+9dsk4qDNVfFglDX7Jpqki+ fw9RpmR8Lg0Qxl949ygPlTCpsDtMFTHvilXcOfJoZc18lHjnZ6BWG0bY2wf1EiJyRdl1 ibOo7kT+aTI5APN5/36u6tlnJdsz6LylQL7moSWH9lGldec1Yr2cqGSx3lelc15Hk6Y4 rLA38CGJX43MiuYaVYo9lgtX/9E9PCUs7s5bxXR4VnkLzQ2CuHXJuxILM1fKLFWCk0j9 Ep4w== X-Gm-Message-State: AJIora+q+wYUnfmxJ7mvv40sZMGTZAnZhKMKWg89Uiym2MZSbQzhyiWd z9FXcyFtzea2khBMmoX40MjVLg== X-Google-Smtp-Source: AGRyM1vFAMaVxrejgeHUVQtzbSf/+IsHavPxXruTBVbtBZT+dYhiGU9cCoDUlUW+zQyF/K8weo8tQA== X-Received: by 2002:a05:6402:50f:b0:435:7996:e90f with SMTP id m15-20020a056402050f00b004357996e90fmr7436475edv.110.1656196452357; Sat, 25 Jun 2022 15:34:12 -0700 (PDT) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id o7-20020a170906860700b00722d5f07864sm3004263ejx.225.2022.06.25.15.34.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 25 Jun 2022 15:34:11 -0700 (PDT) Date: Sun, 26 Jun 2022 00:34:10 +0200 From: Daniel Vetter To: Helge Deller Cc: dri-devel@lists.freedesktop.org, daniel.vetter@ffwll.ch, linux-fbdev@vger.kernel.org Subject: Re: [PATCH v3 4/4] fbmem: Prevent invalid virtual screen sizes Message-ID: References: <20220625220630.333705-1-deller@gmx.de> <20220625220630.333705-5-deller@gmx.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220625220630.333705-5-deller@gmx.de> X-Operating-System: Linux phenom 5.10.0-8-amd64 Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org On Sun, Jun 26, 2022 at 12:06:30AM +0200, Helge Deller wrote: > Prevent that drivers or the user sets the virtual screen resolution > smaller than the physical screen resolution. This is important, because > otherwise we may get accesses outside of the graphics memory area. > > Signed-off-by: Helge Deller > Cc: stable@vger.kernel.org # v5.4+ Reviewed-by: Daniel Vetter > --- > drivers/video/fbdev/core/fbmem.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c > index 160389365a36..b6e1d0f2b974 100644 > --- a/drivers/video/fbdev/core/fbmem.c > +++ b/drivers/video/fbdev/core/fbmem.c > @@ -1006,6 +1006,12 @@ fb_set_var(struct fb_info *info, struct fb_var_screeninfo *var) > if (var->xres < 8 || var->yres < 8) > return -EINVAL; > > + /* make sure virtual resolution >= physical resolution */ > + if (var->xres_virtual < var->xres) > + return -EINVAL; > + if (var->yres_virtual < var->yres) > + return -EINVAL; > + > /* Too huge resolution causes multiplication overflow. */ > if (check_mul_overflow(var->xres, var->yres, &unused) || > check_mul_overflow(var->xres_virtual, var->yres_virtual, &unused)) > -- > 2.35.3 > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch