linux-kernel - [PATCH 6/6] ima: do not send field length to userspace for digest of ima template

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1384523146-9290-7-git-send-email-roberto.sassu@polito.it>
Date:	Fri, 15 Nov 2013 14:45:44 +0100
From:	Roberto Sassu <roberto.sassu@...ito.it>
To:	linux-security-module@...r.kernel.org
Cc:	linux-kernel@...r.kernel.org,
	linux-ima-devel@...ts.sourceforge.net, zohar@...ibm.com,
	d.kasatkin@...sung.com, james.l.morris@...cle.com,
	Roberto Sassu <roberto.sassu@...ito.it>,
	Mimi Zohar <zohar@...ux.vnet.ibm.com>
Subject: [PATCH 6/6] ima: do not send field length to userspace for digest of ima template

This patch defines a new value for the 'ima_show_type' enumerator
(IMA_SHOW_BINARY_NO_FIELD_LEN) to prevent that the field length
is transmitted through the 'binary_runtime_measurements' interface
for the digest field of the 'ima' template.

Signed-off-by: Roberto Sassu <roberto.sassu@...ito.it>
Signed-off-by: Mimi Zohar <zohar@...ux.vnet.ibm.com>
---
 security/integrity/ima/ima.h              |  3 ++-
 security/integrity/ima/ima_fs.c           | 14 +++++++++++---
 security/integrity/ima/ima_template_lib.c |  6 +++++-
 3 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index a21cf70..9636e17 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -26,7 +26,8 @@
 
 #include "../integrity.h"
 
-enum ima_show_type { IMA_SHOW_BINARY, IMA_SHOW_ASCII };
+enum ima_show_type { IMA_SHOW_BINARY, IMA_SHOW_BINARY_NO_FIELD_LEN,
+		     IMA_SHOW_ASCII };
 enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = 8 };
 
 /* digest size for IMA, fits SHA1 or MD5 */
diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c
index d47a7c8..db01125 100644
--- a/security/integrity/ima/ima_fs.c
+++ b/security/integrity/ima/ima_fs.c
@@ -120,6 +120,7 @@ static int ima_measurements_show(struct seq_file *m, void *v)
 	struct ima_template_entry *e;
 	int namelen;
 	u32 pcr = CONFIG_IMA_MEASURE_PCR_IDX;
+	bool is_ima_template = false;
 	int i;
 
 	/* get entry */
@@ -145,14 +146,21 @@ static int ima_measurements_show(struct seq_file *m, void *v)
 	ima_putc(m, e->template_desc->name, namelen);
 
 	/* 5th:  template length (except for 'ima' template) */
-	if (strcmp(e->template_desc->name, IMA_TEMPLATE_IMA_NAME) != 0)
+	if (strcmp(e->template_desc->name, IMA_TEMPLATE_IMA_NAME) == 0)
+		is_ima_template = true;
+
+	if (!is_ima_template)
 		ima_putc(m, &e->template_data_len,
 			 sizeof(e->template_data_len));
 
 	/* 6th:  template specific data */
 	for (i = 0; i < e->template_desc->num_fields; i++) {
-		e->template_desc->fields[i]->field_show(m, IMA_SHOW_BINARY,
-							&e->template_data[i]);
+		enum ima_show_type show = IMA_SHOW_BINARY;
+		struct ima_template_field *field = e->template_desc->fields[i];
+
+		if (is_ima_template && strcmp(field->field_id, "d") == 0)
+			show = IMA_SHOW_BINARY_NO_FIELD_LEN;
+		field->field_show(m, show, &e->template_data[i]);
 	}
 	return 0;
 }
diff --git a/security/integrity/ima/ima_template_lib.c b/security/integrity/ima/ima_template_lib.c
index 6d01c69..1683bbf 100644
--- a/security/integrity/ima/ima_template_lib.c
+++ b/security/integrity/ima/ima_template_lib.c
@@ -109,9 +109,12 @@ static void ima_show_template_data_binary(struct seq_file *m,
 					  enum data_formats datafmt,
 					  struct ima_field_data *field_data)
 {
-	ima_putc(m, &field_data->len, sizeof(u32));
+	if (show != IMA_SHOW_BINARY_NO_FIELD_LEN)
+		ima_putc(m, &field_data->len, sizeof(u32));
+
 	if (!field_data->len)
 		return;
+
 	ima_putc(m, field_data->data, field_data->len);
 }
 
@@ -125,6 +128,7 @@ static void ima_show_template_field_data(struct seq_file *m,
 		ima_show_template_data_ascii(m, show, datafmt, field_data);
 		break;
 	case IMA_SHOW_BINARY:
+	case IMA_SHOW_BINARY_NO_FIELD_LEN:
 		ima_show_template_data_binary(m, show, datafmt, field_data);
 		break;
 	default:
-- 
1.8.1.4


Download attachment "smime.p7s" of type "application/x-pkcs7-signature" (2061 bytes)