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 680E8C433EF for ; Mon, 11 Jul 2022 09:57:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234198AbiGKJ5S (ORCPT ); Mon, 11 Jul 2022 05:57:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49332 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234041AbiGKJ4t (ORCPT ); Mon, 11 Jul 2022 05:56:49 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 82E8FB4189; Mon, 11 Jul 2022 02:26:50 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 30F2AB80E92; Mon, 11 Jul 2022 09:26:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 86B7AC34115; Mon, 11 Jul 2022 09:26:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1657531595; bh=S9mbCzU3aDaS30PbSuhcVdHDJcVEx5OvHyDJ8pSdBd8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MIvELIldhA0oAz3LghBU2dP/0GiSSkz2/CS/t4Yjqq/5lHReDLU/8Wu1vS1LHeQI6 uEi91IB8vu0vUT9lQYEs4Uhm8OhkHvnUGmLLbtTWWw0d1VZPH7P/W+uZKQ5MRA5eQG Jnf/Edpo0LyvtURQK2YbHTSrKQYc5ihEHkNg+/nM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Helge Deller , Daniel Vetter , Geert Uytterhoeven Subject: [PATCH 5.15 161/230] fbcon: Disallow setting font bigger than screen size Date: Mon, 11 Jul 2022 11:06:57 +0200 Message-Id: <20220711090608.628351902@linuxfoundation.org> X-Mailer: git-send-email 2.37.0 In-Reply-To: <20220711090604.055883544@linuxfoundation.org> References: <20220711090604.055883544@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Helge Deller commit 65a01e601dbba8b7a51a2677811f70f783766682 upstream. Prevent that users set a font size which is bigger than the physical screen. It's unlikely this may happen (because screens are usually much larger than the fonts and each font char is limited to 32x32 pixels), but it may happen on smaller screens/LCD displays. Signed-off-by: Helge Deller Reviewed-by: Daniel Vetter Reviewed-by: Geert Uytterhoeven Cc: stable@vger.kernel.org # v4.14+ Signed-off-by: Greg Kroah-Hartman --- drivers/video/fbdev/core/fbcon.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/drivers/video/fbdev/core/fbcon.c +++ b/drivers/video/fbdev/core/fbcon.c @@ -2480,6 +2480,11 @@ static int fbcon_set_font(struct vc_data if (charcount != 256 && charcount != 512) return -EINVAL; + /* font bigger than screen resolution ? */ + if (w > FBCON_SWAP(info->var.rotate, info->var.xres, info->var.yres) || + h > FBCON_SWAP(info->var.rotate, info->var.yres, info->var.xres)) + return -EINVAL; + /* Make sure drawing engine can handle the font */ if (!(info->pixmap.blit_x & (1 << (font->width - 1))) || !(info->pixmap.blit_y & (1 << (font->height - 1))))