Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

Pull IMA fixes from James Morris:
 "These three patches fix regressions in the IMA code in your current
  tree.

  The first fixes a couple of bugs in template_desc_init_fields(), and
  the other two ensure that changes in this kernel don't break
  userspace"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  ima: make a copy of template_fmt in template_desc_init_fields()
  ima: do not send field length to userspace for digest of ima template
  ima: do not include field length in template digest calc for ima template

6 files changed, 47 insertions, 18 deletions

diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index bf03c6a16cc83..9636e17c9f5d7 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 */
@@ -97,7 +98,8 @@ int ima_add_template_entry(struct ima_template_entry *entry, int violation,
 			   const char *op, struct inode *inode,
 			   const unsigned char *filename);
 int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash);
-int ima_calc_field_array_hash(struct ima_field_data *field_data, int num_fields,
+int ima_calc_field_array_hash(struct ima_field_data *field_data,
+			      struct ima_template_desc *desc, int num_fields,
 			      struct ima_digest_data *hash);
 int __init ima_calc_boot_aggregate(struct ima_digest_data *hash);
 void ima_add_violation(struct file *file, const unsigned char *filename,
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index 0e7540863fc29..80374842fe0bb 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -94,6 +94,7 @@ int ima_store_template(struct ima_template_entry *entry,
 		/* this function uses default algo */
 		hash.hdr.algo = HASH_ALGO_SHA1;
 		result = ima_calc_field_array_hash(&entry->template_data[0],
+						   entry->template_desc,
 						   num_fields, &hash.hdr);
 		if (result < 0) {
 			integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode,
diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c
index 676e0292dfecf..fdf60def52e90 100644
--- a/security/integrity/ima/ima_crypto.c
+++ b/security/integrity/ima/ima_crypto.c
@@ -140,6 +140,7 @@ int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash)
  * Calculate the hash of template data
  */
 static int ima_calc_field_array_hash_tfm(struct ima_field_data *field_data,
+					 struct ima_template_desc *td,
 					 int num_fields,
 					 struct ima_digest_data *hash,
 					 struct crypto_shash *tfm)
@@ -160,9 +161,13 @@ static int ima_calc_field_array_hash_tfm(struct ima_field_data *field_data,
 		return rc;
 
 	for (i = 0; i < num_fields; i++) {
-		rc = crypto_shash_update(&desc.shash,
-					 (const u8 *) &field_data[i].len,
-					 sizeof(field_data[i].len));
+		if (strcmp(td->name, IMA_TEMPLATE_IMA_NAME) != 0) {
+			rc = crypto_shash_update(&desc.shash,
+						(const u8 *) &field_data[i].len,
+						sizeof(field_data[i].len));
+			if (rc)
+				break;
+		}
 		rc = crypto_shash_update(&desc.shash, field_data[i].data,
 					 field_data[i].len);
 		if (rc)
@@ -175,7 +180,8 @@ static int ima_calc_field_array_hash_tfm(struct ima_field_data *field_data,
 	return rc;
 }
 
-int ima_calc_field_array_hash(struct ima_field_data *field_data, int num_fields,
+int ima_calc_field_array_hash(struct ima_field_data *field_data,
+			      struct ima_template_desc *desc, int num_fields,
 			      struct ima_digest_data *hash)
 {
 	struct crypto_shash *tfm;
@@ -185,7 +191,8 @@ int ima_calc_field_array_hash(struct ima_field_data *field_data, int num_fields,
 	if (IS_ERR(tfm))
 		return PTR_ERR(tfm);
 
-	rc = ima_calc_field_array_hash_tfm(field_data, num_fields, hash, tfm);
+	rc = ima_calc_field_array_hash_tfm(field_data, desc, num_fields,
+					   hash, tfm);
 
 	ima_free_tfm(tfm);
 
diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c
index d47a7c86a21d0..db01125926bdb 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.c b/security/integrity/ima/ima_template.c
index 4e5da990630be..913e1927f916f 100644
--- a/security/integrity/ima/ima_template.c
+++ b/security/integrity/ima/ima_template.c
@@ -90,7 +90,7 @@ static struct ima_template_field *lookup_template_field(const char *field_id)
 	return NULL;
 }
 
-static int template_fmt_size(char *template_fmt)
+static int template_fmt_size(const char *template_fmt)
 {
 	char c;
 	int template_fmt_len = strlen(template_fmt);
@@ -106,23 +106,28 @@ static int template_fmt_size(char *template_fmt)
 	return j + 1;
 }
 
-static int template_desc_init_fields(char *template_fmt,
+static int template_desc_init_fields(const char *template_fmt,
 				     struct ima_template_field ***fields,
 				     int *num_fields)
 {
-	char *c, *template_fmt_ptr = template_fmt;
+	char *c, *template_fmt_copy;
 	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;
+
 	*fields = kzalloc(template_num_fields * sizeof(*fields), GFP_KERNEL);
 	if (*fields == NULL) {
 		result = -ENOMEM;
 		goto out;
 	}
-	for (i = 0; (c = strsep(&template_fmt_ptr, "|")) != NULL &&
+	for (i = 0; (c = strsep(&template_fmt_copy, "|")) != NULL &&
 	     i < template_num_fields; i++) {
 		struct ima_template_field *f = lookup_template_field(c);
 
@@ -133,10 +138,12 @@ static int template_desc_init_fields(char *template_fmt,
 		(*fields)[i] = f;
 	}
 	*num_fields = i;
-	return 0;
 out:
-	kfree(*fields);
-	*fields = NULL;
+	if (result < 0) {
+		kfree(*fields);
+		*fields = NULL;
+	}
+	kfree(template_fmt_copy);
 	return result;
 }
 
diff --git a/security/integrity/ima/ima_template_lib.c b/security/integrity/ima/ima_template_lib.c
index 6d66ad6ed265f..c38adcc910fbb 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: