From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755395Ab0IOVur (ORCPT ); Wed, 15 Sep 2010 17:50:47 -0400 Received: from mx1.vsecurity.com ([209.67.252.12]:61126 "EHLO mx1.vsecurity.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755213Ab0IOVub (ORCPT ); Wed, 15 Sep 2010 17:50:31 -0400 Subject: [PATCH] drivers/serial/serial_core.c: prevent reading uninitialized stack memory From: Dan Rosenberg To: gregkh@suse.de Cc: linux-kernel@vger.kernel.org, security@kernel.org Content-Type: text/plain; charset="UTF-8" Date: Wed, 15 Sep 2010 17:44:09 -0400 Message-ID: <1284587049.6275.99.camel@dan> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The TIOCGICOUNT device ioctl allows unprivileged users to read uninitialized stack memory, because the "reserved" member of the serial_icounter_struct struct declared on the stack is not altered or zeroed before being copied back to the user. This patch takes care of it. Signed-off-by: Dan Rosenberg --- linux-2.6.35.4.orig/drivers/serial/serial_core.c 2010-08-26 19:47:12.000000000 -0400 +++ linux-2.6.35.4/drivers/serial/serial_core.c 2010-09-15 13:57:04.767375072 -0400 @@ -1081,6 +1081,8 @@ static int uart_get_count(struct uart_st struct uart_icount cnow; struct uart_port *uport = state->uart_port; + memset(&icount, 0, sizeof(struct serial_icounter_struct)); + spin_lock_irq(&uport->lock); memcpy(&cnow, &uport->icount, sizeof(struct uart_icount)); spin_unlock_irq(&uport->lock);