ima: Define new template fields xattrnames, xattrlengths and xattrvalues

This patch defines the new template fields xattrnames, xattrlengths and
xattrvalues, which contain respectively a list of xattr names (strings,
separated by |), lengths (u32, hex) and values (hex). If an xattr is not
present, the name and length are not displayed in the measurement list.

Reported-by: kernel test robot <lkp@intel.com> (Missing prototype def)
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

3 files changed, 79 insertions, 0 deletions

diff --git a/security/integrity/ima/ima_template.c b/security/integrity/ima/ima_template.c
index 43784f2bf8bd..159a31d2fcdf 100644
--- a/security/integrity/ima/ima_template.c
+++ b/security/integrity/ima/ima_template.c
@@ -53,6 +53,15 @@ static const struct ima_template_field supported_fields[] = {
 	 .field_show = ima_show_template_uint},
 	{.field_id = "imode", .field_init = ima_eventinodemode_init,
 	 .field_show = ima_show_template_uint},
+	{.field_id = "xattrnames",
+	 .field_init = ima_eventinodexattrnames_init,
+	 .field_show = ima_show_template_string},
+	{.field_id = "xattrlengths",
+	 .field_init = ima_eventinodexattrlengths_init,
+	 .field_show = ima_show_template_sig},
+	{.field_id = "xattrvalues",
+	 .field_init = ima_eventinodexattrvalues_init,
+	 .field_show = ima_show_template_sig},
 };
 
 /*
diff --git a/security/integrity/ima/ima_template_lib.c b/security/integrity/ima/ima_template_lib.c
index 3156fb34b1af..518fd50ea48a 100644
--- a/security/integrity/ima/ima_template_lib.c
+++ b/security/integrity/ima/ima_template_lib.c
@@ -11,6 +11,7 @@
 
 #include "ima_template_lib.h"
 #include <linux/xattr.h>
+#include <linux/evm.h>
 
 static bool ima_template_hash_algo_allowed(u8 algo)
 {
@@ -618,3 +619,66 @@ int ima_eventinodemode_init(struct ima_event_data *event_data,
 	return ima_write_template_field_data((char *)&mode, sizeof(mode),
 					     DATA_FMT_UINT, field_data);
 }
+
+static int ima_eventinodexattrs_init_common(struct ima_event_data *event_data,
+					    struct ima_field_data *field_data,
+					    char type)
+{
+	u8 *buffer = NULL;
+	int rc;
+
+	if (!event_data->file)
+		return 0;
+
+	rc = evm_read_protected_xattrs(file_dentry(event_data->file), NULL, 0,
+				       type, ima_canonical_fmt);
+	if (rc < 0)
+		return 0;
+
+	buffer = kmalloc(rc, GFP_KERNEL);
+	if (!buffer)
+		return 0;
+
+	rc = evm_read_protected_xattrs(file_dentry(event_data->file), buffer,
+				       rc, type, ima_canonical_fmt);
+	if (rc < 0) {
+		rc = 0;
+		goto out;
+	}
+
+	rc = ima_write_template_field_data((char *)buffer, rc, DATA_FMT_HEX,
+					   field_data);
+out:
+	kfree(buffer);
+	return rc;
+}
+
+/*
+ *  ima_eventinodexattrnames_init - include a list of xattr names as part of the
+ *  template data
+ */
+int ima_eventinodexattrnames_init(struct ima_event_data *event_data,
+				  struct ima_field_data *field_data)
+{
+	return ima_eventinodexattrs_init_common(event_data, field_data, 'n');
+}
+
+/*
+ *  ima_eventinodexattrlengths_init - include a list of xattr lengths as part of
+ *  the template data
+ */
+int ima_eventinodexattrlengths_init(struct ima_event_data *event_data,
+				    struct ima_field_data *field_data)
+{
+	return ima_eventinodexattrs_init_common(event_data, field_data, 'l');
+}
+
+/*
+ *  ima_eventinodexattrvalues_init - include a list of xattr values as part of
+ *  the template data
+ */
+int ima_eventinodexattrvalues_init(struct ima_event_data *event_data,
+				   struct ima_field_data *field_data)
+{
+	return ima_eventinodexattrs_init_common(event_data, field_data, 'v');
+}
diff --git a/security/integrity/ima/ima_template_lib.h b/security/integrity/ima/ima_template_lib.h
index 6509af4a97ee..c71f1de95753 100644
--- a/security/integrity/ima/ima_template_lib.h
+++ b/security/integrity/ima/ima_template_lib.h
@@ -56,4 +56,10 @@ int ima_eventinodegid_init(struct ima_event_data *event_data,
 			   struct ima_field_data *field_data);
 int ima_eventinodemode_init(struct ima_event_data *event_data,
 			    struct ima_field_data *field_data);
+int ima_eventinodexattrnames_init(struct ima_event_data *event_data,
+				  struct ima_field_data *field_data);
+int ima_eventinodexattrlengths_init(struct ima_event_data *event_data,
+				    struct ima_field_data *field_data);
+int ima_eventinodexattrvalues_init(struct ima_event_data *event_data,
+				   struct ima_field_data *field_data);
 #endif /* __LINUX_IMA_TEMPLATE_LIB_H */