From 0260643ce8047d2a58f76222d09f161149622465 Mon Sep 17 00:00:00 2001 From: Eric Richter Date: Wed, 1 Jun 2016 13:14:01 -0500 Subject: [PATCH] ima: add policy support for extending different pcrs This patch defines a new IMA measurement policy rule option "pcr=", which allows extending different PCRs on a per rule basis. For example, the system independent files could extend the default IMA Kconfig specified PCR, while the system dependent files could extend a different PCR. The following is an example of this usage with an SELinux policy; the rule would extend PCR 11 with system configuration files: measure func=FILE_CHECK mask=MAY_READ obj_type=system_conf_t pcr=11 Changelog v3: - FIELD_SIZEOF returns bytes, not bits. Fixed INVALID_PCR Signed-off-by: Eric Richter Signed-off-by: Mimi Zohar --- security/integrity/ima/ima_policy.c | 29 ++++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-) diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 0f887a564a29..3d35fbe3be0b 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -32,6 +32,7 @@ #define IMA_FSUUID 0x0020 #define IMA_INMASK 0x0040 #define IMA_EUID 0x0080 +#define IMA_PCR 0x0100 #define UNKNOWN 0 #define MEASURE 0x0001 /* same as IMA_MEASURE */ @@ -40,6 +41,9 @@ #define DONT_APPRAISE 0x0008 #define AUDIT 0x0040 +#define INVALID_PCR(a) (((a) < 0) || \ + (a) >= (FIELD_SIZEOF(struct integrity_iint_cache, measured_pcrs) * 8)) + int ima_policy_flag; static int temp_ima_appraise; @@ -60,6 +64,7 @@ struct ima_rule_entry { u8 fsuuid[16]; kuid_t uid; kuid_t fowner; + int pcr; struct { void *rule; /* LSM file metadata specific */ void *args_p; /* audit value */ @@ -478,7 +483,8 @@ enum { Opt_subj_user, Opt_subj_role, Opt_subj_type, Opt_func, Opt_mask, Opt_fsmagic, Opt_fsuuid, Opt_uid, Opt_euid, Opt_fowner, - Opt_appraise_type, Opt_permit_directio + Opt_appraise_type, Opt_permit_directio, + Opt_pcr }; static match_table_t policy_tokens = { @@ -502,6 +508,7 @@ static match_table_t policy_tokens = { {Opt_fowner, "fowner=%s"}, {Opt_appraise_type, "appraise_type=%s"}, {Opt_permit_directio, "permit_directio"}, + {Opt_pcr, "pcr=%s"}, {Opt_err, NULL} }; @@ -773,6 +780,20 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) break; case Opt_permit_directio: entry->flags |= IMA_PERMIT_DIRECTIO; + break; + case Opt_pcr: + if (entry->action != MEASURE) { + result = -EINVAL; + break; + } + ima_log_string(ab, "pcr", args[0].from); + + result = kstrtoint(args[0].from, 10, &entry->pcr); + if (result || INVALID_PCR(entry->pcr)) + result = -EINVAL; + else + entry->flags |= IMA_PCR; + break; case Opt_err: ima_log_string(ab, "UNKNOWN", p); @@ -1011,6 +1032,12 @@ int ima_policy_show(struct seq_file *m, void *v) seq_puts(m, " "); } + if (entry->flags & IMA_PCR) { + snprintf(tbuf, sizeof(tbuf), "%d", entry->pcr); + seq_printf(m, pt(Opt_pcr), tbuf); + seq_puts(m, " "); + } + if (entry->flags & IMA_FSUUID) { seq_printf(m, "fsuuid=%pU", entry->fsuuid); seq_puts(m, " "); -- 2.20.1