From c2426d2ad5027397342107b7ff094aa9b234acb8 Mon Sep 17 00:00:00 2001 From: Roberto Sassu Date: Mon, 13 Oct 2014 14:08:42 +0200 Subject: ima: added support for new kernel cmdline parameter ima_template_fmt This patch allows users to provide a custom template format through the new kernel command line parameter 'ima_template_fmt'. If the supplied format is not valid, IMA uses the default template descriptor. Changelog: - v3: - added check for 'fields' and 'num_fields' in template_desc_init_fields() (suggested by Mimi Zohar) - v2: - using template_desc_init_fields() to validate a format string (Roberto Sassu) - updated documentation by stating that only the chosen template descriptor is initialized (Roberto Sassu) - v1: - simplified code of ima_template_fmt_setup() (Roberto Sassu, suggested by Mimi Zohar) Signed-off-by: Roberto Sassu Signed-off-by: Mimi Zohar --- security/integrity/ima/ima_template.c | 39 ++++++++++++++++++++++++++++++----- 1 file changed, 34 insertions(+), 5 deletions(-) (limited to 'security/integrity') diff --git a/security/integrity/ima/ima_template.c b/security/integrity/ima/ima_template.c index 65117ba06809..0b7404ebfa80 100644 --- a/security/integrity/ima/ima_template.c +++ b/security/integrity/ima/ima_template.c @@ -24,6 +24,7 @@ static struct ima_template_desc defined_templates[] = { {.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 = "", .fmt = ""}, /* placeholder for a custom format */ }; static struct ima_template_field supported_fields[] = { @@ -41,12 +42,18 @@ static struct ima_template_field supported_fields[] = { 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); static int __init ima_template_setup(char *str) { struct ima_template_desc *template_desc; int template_len = strlen(str); + if (ima_template) + return 1; + /* * Verify that a template with the supplied name exists. * If not, use CONFIG_IMA_DEFAULT_TEMPLATE. @@ -73,6 +80,25 @@ static int __init ima_template_setup(char *str) } __setup("ima_template=", ima_template_setup); +static int __init ima_template_fmt_setup(char *str) +{ + int num_templates = ARRAY_SIZE(defined_templates); + + if (ima_template) + return 1; + + if (template_desc_init_fields(str, NULL, NULL) < 0) { + pr_err("format string '%s' not valid, using template %s\n", + str, CONFIG_IMA_DEFAULT_TEMPLATE); + return 1; + } + + defined_templates[num_templates - 1].fmt = str; + ima_template = defined_templates + num_templates - 1; + return 1; +} +__setup("ima_template_fmt=", ima_template_fmt_setup); + static struct ima_template_desc *lookup_template_desc(const char *name) { int i; @@ -146,12 +172,15 @@ static int template_desc_init_fields(const char *template_fmt, } } - *fields = kmalloc_array(i, sizeof(*fields), GFP_KERNEL); - if (*fields == NULL) - return -ENOMEM; + if (fields && num_fields) { + *fields = kmalloc_array(i, sizeof(*fields), GFP_KERNEL); + if (*fields == NULL) + return -ENOMEM; + + memcpy(*fields, found_fields, i * sizeof(*fields)); + *num_fields = i; + } - memcpy(*fields, found_fields, i * sizeof(*fields)); - *num_fields = i; return 0; } -- cgit v1.2.3-59-g8ed1b