From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755858Ab3KVQii (ORCPT ); Fri, 22 Nov 2013 11:38:38 -0500 Received: from fm2nodo5.polito.it ([130.192.180.14]:44178 "EHLO fm2nodo5.polito.it" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753381Ab3KVQig (ORCPT ); Fri, 22 Nov 2013 11:38:36 -0500 X-ExtScanner: Niversoft's FindAttachments (free) Message-ID: <528F882B.5050808@polito.it> Date: Fri, 22 Nov 2013 17:36:59 +0100 From: Roberto Sassu Organization: Politecnico di Torino User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.1.0 MIME-Version: 1.0 To: Heiko Carstens CC: Mimi Zohar , Martin Schwidefsky , linux-kernel@vger.kernel.org Subject: Re: [BUG] 3ce1217d6cd5 ima patch causes s390 to crash on boot References: <20131122114819.GB4208@osiris> <528F5C01.8020304@polito.it> <20131122141314.GC4208@osiris> <528F8515.7040201@polito.it> <20131122163502.GE4208@osiris> In-Reply-To: <20131122163502.GE4208@osiris> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-FEAS-SYSTEM-WL: 130.192.180.41 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/22/2013 05:35 PM, Heiko Carstens wrote: > On Fri, Nov 22, 2013 at 05:23:49PM +0100, Roberto Sassu wrote: >> Another problem that I found is that strsep() >> modifies the source buffer by replacing the separator >> character with '\0'. In particular, this function >> modifies static data initialized at the beginning >> of the ima_template.c file. Maybe, this is causing >> the kernel panic. I already sent a patch to fix this >> problem (attached to the email) even if it is not >> supposed to land on the 3.13 kernel. Let me know >> if this fixes the issue. Otherwise, I will check >> the code more in depth. > > With your patch below applied the kernel boots again. > So it should go into 3.13 (or a different fix). > Ok, good. Yes, we will apply this patch to the 3.13 kernel. > Thanks! No problem. Roberto > >> From 2d3aa1c0328c44ecc3af7de162791c8cddfb6dfd Mon Sep 17 00:00:00 2001 >> From: Roberto Sassu >> Date: Wed, 6 Nov 2013 13:51:35 +0100 >> Subject: [RFC][PATCH 2/4] ima: make a copy of template_fmt in >> template_desc_init_fields() >> >> This patch makes a copy of the 'template_fmt' function argument so that >> the latter will not be modified by strsep(), which does the splitting by >> replacing the given separator with '\0'. >> >> Signed-off-by: Roberto Sassu >> --- >> security/integrity/ima/ima_template.c | 9 ++++++++- >> 1 file changed, 8 insertions(+), 1 deletion(-) >> >> diff --git a/security/integrity/ima/ima_template.c b/security/integrity/ima/ima_template.c >> index 7bcff5c..bb33576 100644 >> --- a/security/integrity/ima/ima_template.c >> +++ b/security/integrity/ima/ima_template.c >> @@ -113,13 +113,19 @@ static int template_desc_init_fields(char *template_fmt, >> struct ima_template_field ***fields, >> int *num_fields) >> { >> - char *c, *template_fmt_ptr = template_fmt; >> + char *c, *template_fmt_ptr, *template_fmt_copy = NULL; >> int template_num_fields = template_fmt_size(template_fmt); >> int i, result = 0; >> >> if (template_num_fields > IMA_TEMPLATE_NUM_FIELDS_MAX) >> return -EINVAL; >> >> + /* copying is needed as strsep() modifies the original buffer */ >> + template_fmt_copy = kstrdup(template_fmt, GFP_KERNEL); >> + if (template_fmt_copy == NULL) >> + return -ENOMEM; >> + >> + template_fmt_ptr = template_fmt_copy; >> *fields = kzalloc(template_num_fields * sizeof(*fields), GFP_KERNEL); >> if (*fields == NULL) { >> result = -ENOMEM; >> @@ -139,6 +145,7 @@ static int template_desc_init_fields(char *template_fmt, >> *num_fields = i; >> return 0; >> out: >> + kfree(template_fmt_copy); >> kfree(*fields); >> *fields = NULL; >> return result; >> -- >> 1.8.1.4 >> >