From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754492AbaCKJ7Y (ORCPT ); Tue, 11 Mar 2014 05:59:24 -0400 Received: from arkanian.console-pimps.org ([212.110.184.194]:58699 "EHLO arkanian.console-pimps.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752793AbaCKJ7T (ORCPT ); Tue, 11 Mar 2014 05:59:19 -0400 Date: Tue, 11 Mar 2014 09:59:10 +0000 From: Matt Fleming To: Kees Cook Cc: Paul Mundt , kbuild test robot , LKML , Andrew Morton Subject: Re: [kees:format-security 2/3] arch/sh/kernel/dumpstack.c:118:2: error: format not a string literal and no format arguments Message-ID: <20140311095910.GA5834@console-pimps.org> References: <531d3b0e.4MeVQMzUoamEWeW7%fengguang.wu@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 10 Mar, at 10:41:57AM, Kees Cook wrote: > > 4e14dfc7 Matt Fleming 2009-08-07 113 /* > > 4e14dfc7 Matt Fleming 2009-08-07 114 * Print one address/symbol entries per line. > > 4e14dfc7 Matt Fleming 2009-08-07 115 */ > > 4e14dfc7 Matt Fleming 2009-08-07 116 static void print_trace_address(void *data, unsigned long addr, int reliable) > > 4e14dfc7 Matt Fleming 2009-08-07 117 { > > 4e14dfc7 Matt Fleming 2009-08-07 @118 printk(data); > > This needs to be "printk("%s", data);" so there is no chance of having > "data" interpreted as a format string itself. OMG, I suck. Thanks for the report Kees. Have you got a patch for x86? I think that's where this code came from. Including Andrew, because I'm not sure who else is going to take this patch. --- >>From 2284f3a27f68cec665aa982c0a226cf3fbf96ddf Mon Sep 17 00:00:00 2001 From: Matt Fleming Date: Tue, 11 Mar 2014 09:50:26 +0000 Subject: [PATCH] sh: Fix format string bug in stack tracer Kees reported the following error, arch/sh/kernel/dumpstack.c: In function 'print_trace_address': >> arch/sh/kernel/dumpstack.c:118:2: error: format not a string literal and no format arguments [-Werror=format-security] Use the "%s" format so that it's impossible to interpret 'data' as a format string. Reported-by: Kees Cook Cc: Paul Mundt Cc: Andrew Morton Cc: stable@vger.kernel.org Signed-off-by: Matt Fleming --- arch/sh/kernel/dumpstack.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/sh/kernel/dumpstack.c b/arch/sh/kernel/dumpstack.c index b959f5592604..8dfe645bcc4b 100644 --- a/arch/sh/kernel/dumpstack.c +++ b/arch/sh/kernel/dumpstack.c @@ -115,7 +115,7 @@ static int print_trace_stack(void *data, char *name) */ static void print_trace_address(void *data, unsigned long addr, int reliable) { - printk(data); + printk("%s", (char *)data); printk_address(addr, reliable); } -- 1.8.5.3 -- Matt Fleming, Intel Open Source Technology Center