From 3e8e5503a33577d89bdb7469b851b11f507bbed6 Mon Sep 17 00:00:00 2001
From: Roberto Sassu <roberto.sassu@polito.it>
Date: Fri, 8 Nov 2013 19:21:40 +0100
Subject: [PATCH] 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.
Fixes commit: 3ce1217 ima: define template fields library and new helpers
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.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 a21cf706d213..9636e17c9f5d 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 d47a7c86a21d..db01125926bd 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 6d66ad6ed265..c38adcc910fb 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:
--
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