Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752659AbdGPOOa (ORCPT ); Sun, 16 Jul 2017 10:14:30 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:44258 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752913AbdGPOOZ (ORCPT ); Sun, 16 Jul 2017 10:14:25 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Roee Hay" , "Greg Kroah-Hartman" , "Willy Tarreau" Date: Sun, 16 Jul 2017 14:56:46 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 175/178] char: lp: fix possible integer overflow in lp_setup() In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1185 Lines: 36 3.16.46-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Willy Tarreau commit 3e21f4af170bebf47c187c1ff8bf155583c9f3b1 upstream. The lp_setup() code doesn't apply any bounds checking when passing "lp=none", and only in this case, resulting in an overflow of the parport_nr[] array. All versions in Git history are affected. Reported-By: Roee Hay Cc: Ben Hutchings Signed-off-by: Willy Tarreau Signed-off-by: Greg Kroah-Hartman Signed-off-by: Ben Hutchings --- drivers/char/lp.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/drivers/char/lp.c +++ b/drivers/char/lp.c @@ -859,7 +859,11 @@ static int __init lp_setup (char *str) } else if (!strcmp(str, "auto")) { parport_nr[0] = LP_PARPORT_AUTO; } else if (!strcmp(str, "none")) { - parport_nr[parport_ptr++] = LP_PARPORT_NONE; + if (parport_ptr < LP_NO) + parport_nr[parport_ptr++] = LP_PARPORT_NONE; + else + printk(KERN_INFO "lp: too many ports, %s ignored.\n", + str); } else if (!strcmp(str, "reset")) { reset = 1; }