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 B35AEC43334 for ; Mon, 11 Jul 2022 09:15:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229984AbiGKJPC (ORCPT ); Mon, 11 Jul 2022 05:15:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59700 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229606AbiGKJNy (ORCPT ); Mon, 11 Jul 2022 05:13:54 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 039AB23BFB; Mon, 11 Jul 2022 02:10:01 -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 dfw.source.kernel.org (Postfix) with ESMTPS id 94C75611E4; Mon, 11 Jul 2022 09:10:00 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9D05EC341CE; Mon, 11 Jul 2022 09:09:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1657530600; bh=YRJkLFHxetNc+M6P65Y2zU3igiMyD3cTSTXJPlfQY80=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GQjQf6EnMVROO37SjeLgqEceU4U/6tgZDiavjrJ171yiMtX0G1YOJ4ahLltu8su2c yNrsW1iFAgpBOnFW7T8uWtsAYPAB+lBxqk/2s2F42UY8RBNr56j/HMBdW4zIe6nzCn 5LL3KCtF2In6wOewOF5kVFPn1QPw/O1sI3OLckow= 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 5.4 11/38] fbcon: Disallow setting font bigger than screen size Date: Mon, 11 Jul 2022 11:06:53 +0200 Message-Id: <20220711090539.061048698@linuxfoundation.org> X-Mailer: git-send-email 2.37.0 In-Reply-To: <20220711090538.722676354@linuxfoundation.org> References: <20220711090538.722676354@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 @@ -2490,6 +2490,11 @@ 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))))