From patchwork Wed Jun 29 20:00:23 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Helge Deller X-Patchwork-Id: 12900660 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 33D55CCA482 for ; Wed, 29 Jun 2022 20:00:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230080AbiF2UAg (ORCPT ); Wed, 29 Jun 2022 16:00:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37006 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230027AbiF2UAe (ORCPT ); Wed, 29 Jun 2022 16:00:34 -0400 Received: from mout.gmx.net (mout.gmx.net [212.227.15.19]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A5E506582 for ; Wed, 29 Jun 2022 13:00:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1656532826; bh=X9zbpRPOh+ldE1nkJcYIH0k5ZFae+4Rxt79Zmb1FBKw=; h=X-UI-Sender-Class:From:To:Subject:Date:In-Reply-To:References; b=gzCJCr+O0d3IlfHCTZCcpw9St22P4VvmLORGZjEkaCaVYJx7KN6c0vsHC2U6NhWYN XmVWASz30uvH/4/kLnOIE7pC4riAIzUXa93CDtuHN+JQWMZjQUXn4PSEcJX5rueYPx Zij1yl2qH3Q2kM1mwp/rAQ4lbahuLmtmmlAtQucU= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from p100.fritz.box ([92.116.135.51]) by mail.gmx.net (mrgmx005 [212.227.17.190]) with ESMTPSA (Nemesis) id 1N2mFi-1ncpPR3KJQ-0132qo; Wed, 29 Jun 2022 22:00:25 +0200 From: Helge Deller To: daniel.vetter@ffwll.ch, linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, geert@linux-m68k.org Subject: [PATCH 4/5] fbmem: Prevent invalid virtual screen sizes in fb_set_var() Date: Wed, 29 Jun 2022 22:00:23 +0200 Message-Id: <20220629200024.187187-5-deller@gmx.de> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20220629200024.187187-1-deller@gmx.de> References: <20220629200024.187187-1-deller@gmx.de> MIME-Version: 1.0 X-Provags-ID: V03:K1:xKmtO/00TE159LdMjEf8AoxwSphDIXVRMyd7+AbgNBGf/mNYsg7 BJK3LQnJudJo9b17lqFUIfsuxBjn87oIF7BsMcF38xCJfSNNIDmZJpW1JJTYcai485HnKso 6GZQ7v/xsITxgNjfX8fOQl7MBjpOIShDfJqGvfqANw1H4/QxPQtqGdpJhmBATwQkJIuRn1e QhO2DHiOV43psWk2N9dog== X-UI-Out-Filterresults: notjunk:1;V03:K0:6M8ukoIwx44=:+xv3kOYUuYBStueuar11to NNzzqBZa1bBHnUd1f5Lwchha/9YEyzKkFfcFFxEvfouQ4jB+5z3Myt41hBa3dugnhtUhA4p8c ruRPZRyYxUgZsC+oJsKgw7D+Nr4xDajUEzMjYXeoAjH2odNU544E49TgQTDt8ImjEZ33LXkFa RLp0Ppfn4LAHxksRENc+NFbfk0NuDmj1HBUKaGJC4PdrAXgibIwpysSRUF0HCBlLdxIVUfW22 RxFueQqi0PC0U3vFBzJPSSEx07n//hb91geZoGjcAQnUhpxcsOC7frEKIc1etjQImV+jDK6Ov cJWh/4DXbEX0oY7g1V2GRSrEsk6SDcVeybHglGuBEb837TD6x/rPziEw0jrM2uCQ4nxD7K0nY m4wVdTUipEVwVtPj82HprreFQ9pIMZ1TumDD61IGq3a6E0X+Lh7Y6HiQHxSpnMdTl14MqudbR +7dE6BtMRcb9d9yc/H9YmYEelkljwEWidv/vo+usNSQ+/FoYxgMyrX5Pr3G5GA5THJjYpa3Hm hhSK53aHaaNkJxN+YsamEq6BZlLejEkI4JTIUQwBOxQMtqAcZtJkFZeP04OG9ti5KDD7ls0Ys YlpW0Pxy0eSS3GdX+Bc/o2Yg1atZg2Hckp/7IChI2p66io4LvYrKlXUvf1wAlWp+hxyfwkeED 9d51JSDtOzde+64XTG6DfTznsjMseJJkr/KZjlwU13bJPzX7HxRRmUMPHSzembOZzykt42LKj LbQyv02oeaYoPHw+P4mGw17ujpqSYQdlm8sBKy6QuVKy7WpP2O+s/8WurrTd64tChNMqFQB3y ha8PZIxnBeXvOJr7TEr72r6kTAfTSJR/qEewjB8VjZ3DJToduYAeO4Beym7c99yxQOyU5H0TY +PIZysDyD76ftt9qzSdPFMxGKvkqYn4kg0MrKt8sLaWRbRty3Y7JD5wEDM4XhiCjyI3Mqi+ZC Wyai0p17eMVZWY26o/35gLaYCS5dPlGGYrbFBLirlnNXg+f29VqCuPEidIiWBV0diEUegSCjp 0x+RJPZ7GOb7d/EggB4DLzr/cotU5VDxs+v7hP5s2ZAylzvkJSNj2RYMyk+oJVykneGR2CLrm VbCHNnJGHt6U8YDOLJ4jE302rYuPLILCoZ4jxjXpfctsZrMeD8kBhKSVw== Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org Prevent that drivers configure a virtual screen resolution smaller than the physical screen resolution. This is important, because otherwise we may access memory outside of the graphics memory area. Signed-off-by: Helge Deller Cc: stable@vger.kernel.org # v5.4+ --- drivers/video/fbdev/core/fbmem.c | 6 ++++++ 1 file changed, 6 insertions(+) -- 2.35.3 diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c index 324f726739c4..222d94e2e0a2 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 (WARN_ON(var->xres_virtual < var->xres)) + var->xres_virtual = var->xres; + if (WARN_ON(var->yres_virtual < var->yres)) + var->yres_virtual = var->yres; + /* 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))