Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932658AbcKIKsA (ORCPT ); Wed, 9 Nov 2016 05:48:00 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:52942 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932393AbcKIKps (ORCPT ); Wed, 9 Nov 2016 05:45:48 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dmitry Vyukov , David Rientjes , One Thousand Gnomes , Jiri Slaby , Peter Hurley , syzkaller@googlegroups.com Subject: [PATCH 4.4 31/69] tty: limit terminal size to 4M chars Date: Wed, 9 Nov 2016 11:44:09 +0100 Message-Id: <20161109102902.431528948@linuxfoundation.org> X-Mailer: git-send-email 2.10.2 In-Reply-To: <20161109102901.127641653@linuxfoundation.org> References: <20161109102901.127641653@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1185 Lines: 38 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dmitry Vyukov commit 32b2921e6a7461fe63b71217067a6cf4bddb132f upstream. Size of kmalloc() in vc_do_resize() is controlled by user. Too large kmalloc() size triggers WARNING message on console. Put a reasonable upper bound on terminal size to prevent WARNINGs. Signed-off-by: Dmitry Vyukov CC: David Rientjes Cc: One Thousand Gnomes Cc: Greg Kroah-Hartman Cc: Jiri Slaby Cc: Peter Hurley Cc: linux-kernel@vger.kernel.org Cc: syzkaller@googlegroups.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/vt/vt.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/tty/vt/vt.c +++ b/drivers/tty/vt/vt.c @@ -872,6 +872,8 @@ static int vc_do_resize(struct tty_struc if (new_cols == vc->vc_cols && new_rows == vc->vc_rows) return 0; + if (new_screen_size > (4 << 20)) + return -EINVAL; newscreen = kmalloc(new_screen_size, GFP_USER); if (!newscreen) return -ENOMEM;