[PATCH v8 08/10] ima: support restoring multiple template formats
From: Mimi Zohar <hidden>
Date: 2016-12-01 01:07:09
Also in:
lkml
Subsystem:
extended verification module (evm), integrity measurement architecture (ima), security subsystem, the rest · Maintainers:
Mimi Zohar, Roberto Sassu, Dmitry Kasatkin, Paul Moore, James Morris, "Serge E. Hallyn", Linus Torvalds
The configured IMA measurement list template format can be replaced at runtime on the boot command line, including a custom template format. This patch adds support for restoring a measuremement list containing multiple builtin/custom template formats. Changelog v7: - remove unnecessary "synchronize_rcu" (reported by Dmitry Kasatkin) Signed-off-by: Mimi Zohar <redacted> Acked-by: Dmitry Kasatkin <dmitry.kasatkin@gmail.com> --- security/integrity/ima/ima_template.c | 52 +++++++++++++++++++++++++++++++++-- 1 file changed, 49 insertions(+), 3 deletions(-)
diff --git a/security/integrity/ima/ima_template.c b/security/integrity/ima/ima_template.c
index 6d60a0847b54..16bbb5a80fc8 100644
--- a/security/integrity/ima/ima_template.c
+++ b/security/integrity/ima/ima_template.c@@ -155,9 +155,14 @@ static int template_desc_init_fields(const char *template_fmt, { const char *template_fmt_ptr; struct ima_template_field *found_fields[IMA_TEMPLATE_NUM_FIELDS_MAX]; - int template_num_fields = template_fmt_size(template_fmt); + int template_num_fields; int i, len; + if (num_fields && *num_fields > 0) /* already initialized? */ + return 0; + + template_num_fields = template_fmt_size(template_fmt); + if (template_num_fields > IMA_TEMPLATE_NUM_FIELDS_MAX) { pr_err("format string '%s' contains too many fields\n", template_fmt);
@@ -236,6 +241,34 @@ int __init ima_init_template(void) return result; } +static struct ima_template_desc *restore_template_fmt(char *template_name) +{ + struct ima_template_desc *template_desc = NULL; + int ret; + + ret = template_desc_init_fields(template_name, NULL, NULL); + if (ret < 0) { + pr_err("attempting to initialize the template \"%s\" failed\n", + template_name); + goto out; + } + + template_desc = kzalloc(sizeof(*template_desc), GFP_KERNEL); + if (!template_desc) + goto out; + + template_desc->name = ""; + template_desc->fmt = kstrdup(template_name, GFP_KERNEL); + if (!template_desc->fmt) + goto out; + + spin_lock(&template_list); + list_add_tail_rcu(&template_desc->list, &defined_templates); + spin_unlock(&template_list); +out: + return template_desc; +} + static int ima_restore_template_data(struct ima_template_desc *template_desc, void *template_data, int template_data_size,
@@ -373,10 +406,23 @@ int ima_restore_measurement_list(loff_t size, void *buf) break; } - /* get template format */ template_desc = lookup_template_desc(template_name); if (!template_desc) { - pr_err("template \"%s\" not found\n", template_name); + template_desc = restore_template_fmt(template_name); + if (!template_desc) + break; + } + + /* + * Only the running system's template format is initialized + * on boot. As needed, initialize the other template formats. + */ + ret = template_desc_init_fields(template_desc->fmt, + &(template_desc->fields), + &(template_desc->num_fields)); + if (ret < 0) { + pr_err("attempting to restore the template fmt \"%s\" \ + failed\n", template_desc->fmt); ret = -EINVAL; break; }
--
2.1.0