From 08f87f769b595151be1afeff53e144f543faa614 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Wed, 06 Dec 2023 09:51:13 +0000
Subject: [PATCH] add dts config

---
 kernel/security/integrity/ima/ima_template.c |   98 +++++++++++++++++++++++++++++++++++-------------
 1 files changed, 71 insertions(+), 27 deletions(-)

diff --git a/kernel/security/integrity/ima/ima_template.c b/kernel/security/integrity/ima/ima_template.c
index 4dfdccc..f64c01d 100644
--- a/kernel/security/integrity/ima/ima_template.c
+++ b/kernel/security/integrity/ima/ima_template.c
@@ -1,19 +1,13 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2013 Politecnico di Torino, Italy
- *                    TORSEC group -- http://security.polito.it
+ *                    TORSEC group -- https://security.polito.it
  *
  * Author: Roberto Sassu <roberto.sassu@polito.it>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation, version 2 of the
- * License.
  *
  * File: ima_template.c
  *      Helpers to manage template descriptors.
  */
-
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/rculist.h>
 #include "ima.h"
@@ -26,6 +20,8 @@
 	{.name = IMA_TEMPLATE_IMA_NAME, .fmt = IMA_TEMPLATE_IMA_FMT},
 	{.name = "ima-ng", .fmt = "d-ng|n-ng"},
 	{.name = "ima-sig", .fmt = "d-ng|n-ng|sig"},
+	{.name = "ima-buf", .fmt = "d-ng|n-ng|buf"},
+	{.name = "ima-modsig", .fmt = "d-ng|n-ng|sig|d-modsig|modsig"},
 	{.name = "", .fmt = ""},	/* placeholder for a custom format */
 };
 
@@ -33,7 +29,7 @@
 static DEFINE_SPINLOCK(template_list);
 static int template_setup_done;
 
-static struct ima_template_field supported_fields[] = {
+static const struct ima_template_field supported_fields[] = {
 	{.field_id = "d", .field_init = ima_eventdigest_init,
 	 .field_show = ima_show_template_digest},
 	{.field_id = "n", .field_init = ima_eventname_init,
@@ -44,14 +40,41 @@
 	 .field_show = ima_show_template_string},
 	{.field_id = "sig", .field_init = ima_eventsig_init,
 	 .field_show = ima_show_template_sig},
+	{.field_id = "buf", .field_init = ima_eventbuf_init,
+	 .field_show = ima_show_template_buf},
+	{.field_id = "d-modsig", .field_init = ima_eventdigest_modsig_init,
+	 .field_show = ima_show_template_digest_ng},
+	{.field_id = "modsig", .field_init = ima_eventmodsig_init,
+	 .field_show = ima_show_template_sig},
 };
-#define MAX_TEMPLATE_NAME_LEN 15
+
+/*
+ * Used when restoring measurements carried over from a kexec. 'd' and 'n' don't
+ * need to be accounted for since they shouldn't be defined in the same template
+ * description as 'd-ng' and 'n-ng' respectively.
+ */
+#define MAX_TEMPLATE_NAME_LEN sizeof("d-ng|n-ng|sig|buf|d-modisg|modsig")
 
 static struct ima_template_desc *ima_template;
-static struct ima_template_desc *lookup_template_desc(const char *name);
-static int template_desc_init_fields(const char *template_fmt,
-				     struct ima_template_field ***fields,
-				     int *num_fields);
+
+/**
+ * ima_template_has_modsig - Check whether template has modsig-related fields.
+ * @ima_template: IMA template to check.
+ *
+ * Tells whether the given template has fields referencing a file's appended
+ * signature.
+ */
+bool ima_template_has_modsig(const struct ima_template_desc *ima_template)
+{
+	int i;
+
+	for (i = 0; i < ima_template->num_fields; i++)
+		if (!strcmp(ima_template->fields[i]->field_id, "modsig") ||
+		    !strcmp(ima_template->fields[i]->field_id, "d-modsig"))
+			return true;
+
+	return false;
+}
 
 static int __init ima_template_setup(char *str)
 {
@@ -112,7 +135,7 @@
 }
 __setup("ima_template_fmt=", ima_template_fmt_setup);
 
-static struct ima_template_desc *lookup_template_desc(const char *name)
+struct ima_template_desc *lookup_template_desc(const char *name)
 {
 	struct ima_template_desc *template_desc;
 	int found = 0;
@@ -129,7 +152,8 @@
 	return found ? template_desc : NULL;
 }
 
-static struct ima_template_field *lookup_template_field(const char *field_id)
+static const struct ima_template_field *
+lookup_template_field(const char *field_id)
 {
 	int i;
 
@@ -156,12 +180,12 @@
 	return j + 1;
 }
 
-static int template_desc_init_fields(const char *template_fmt,
-				     struct ima_template_field ***fields,
-				     int *num_fields)
+int template_desc_init_fields(const char *template_fmt,
+			      const struct ima_template_field ***fields,
+			      int *num_fields)
 {
 	const char *template_fmt_ptr;
-	struct ima_template_field *found_fields[IMA_TEMPLATE_NUM_FIELDS_MAX];
+	const struct ima_template_field *found_fields[IMA_TEMPLATE_NUM_FIELDS_MAX];
 	int template_num_fields;
 	int i, len;
 
@@ -281,20 +305,30 @@
 				     int template_data_size,
 				     struct ima_template_entry **entry)
 {
+	struct tpm_digest *digests;
 	int ret = 0;
 	int i;
 
-	*entry = kzalloc(sizeof(**entry) +
-		    template_desc->num_fields * sizeof(struct ima_field_data),
-		    GFP_NOFS);
+	*entry = kzalloc(struct_size(*entry, template_data,
+				     template_desc->num_fields), GFP_NOFS);
 	if (!*entry)
 		return -ENOMEM;
+
+	digests = kcalloc(NR_BANKS(ima_tpm_chip) + ima_extra_slots,
+			  sizeof(*digests), GFP_NOFS);
+	if (!digests) {
+		kfree(*entry);
+		return -ENOMEM;
+	}
+
+	(*entry)->digests = digests;
 
 	ret = ima_parse_buf(template_data, template_data + template_data_size,
 			    NULL, template_desc->num_fields,
 			    (*entry)->template_data, NULL, NULL,
 			    ENFORCE_FIELDS | ENFORCE_BUFEND, "template data");
 	if (ret < 0) {
+		kfree((*entry)->digests);
 		kfree(*entry);
 		return ret;
 	}
@@ -327,6 +361,7 @@
 int ima_restore_measurement_list(loff_t size, void *buf)
 {
 	char template_name[MAX_TEMPLATE_NAME_LEN];
+	unsigned char zero[TPM_DIGEST_SIZE] = { 0 };
 
 	struct ima_kexec_hdr *khdr = buf;
 	struct ima_field_data hdr[HDR__LAST] = {
@@ -426,10 +461,19 @@
 		if (ret < 0)
 			break;
 
-		memcpy(entry->digest, hdr[HDR_DIGEST].data,
-		       hdr[HDR_DIGEST].len);
-		entry->pcr = !ima_canonical_fmt ? *(hdr[HDR_PCR].data) :
-			     le32_to_cpu(*(hdr[HDR_PCR].data));
+		if (memcmp(hdr[HDR_DIGEST].data, zero, sizeof(zero))) {
+			ret = ima_calc_field_array_hash(
+						&entry->template_data[0],
+						entry);
+			if (ret < 0) {
+				pr_err("cannot calculate template digest\n");
+				ret = -EINVAL;
+				break;
+			}
+		}
+
+		entry->pcr = !ima_canonical_fmt ? *(u32 *)(hdr[HDR_PCR].data) :
+			     le32_to_cpu(*(u32 *)(hdr[HDR_PCR].data));
 		ret = ima_restore_measurement_entry(entry);
 		if (ret < 0)
 			break;

--
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