From c7d09367702e2f4faebc6176d24df72dd5066c3e Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Mon, 19 Dec 2016 16:22:54 -0800 Subject: [PATCH] ima: support restoring multiple template formats 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. Link: http://lkml.kernel.org/r/1480554346-29071-9-git-send-email-zohar@linux.vnet.ibm.com Signed-off-by: Mimi Zohar Acked-by: Dmitry Kasatkin Cc: Thiago Jung Bauermann Cc: "Eric W. Biederman" Cc: Andreas Steffen Cc: Josh Sklar Cc: Dave Young Cc: Vivek Goyal Cc: Baoquan He Cc: Michael Ellerman Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Stewart Smith Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- 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; } -- 2.20.1