1 files changed, 140 insertions, 0 deletions

diff --git a/security/integrity/ima/ima_queue.c b/security/integrity/ima/ima_queue.c
new file mode 100644
index 000000000000..7ec94314ac0c
--- /dev/null
+++ b/security/integrity/ima/ima_queue.c
@@ -0,0 +1,140 @@
+/*
+ * Copyright (C) 2005,2006,2007,2008 IBM Corporation
+ *
+ * Authors:
+ * Serge Hallyn <serue@us.ibm.com>
+ * Reiner Sailer <sailer@watson.ibm.com>
+ * Mimi Zohar <zohar@us.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, version 2 of the
+ * License.
+ *
+ * File: ima_queue.c
+ *       Implements queues that store template measurements and
+ *       maintains aggregate over the stored measurements
+ *       in the pre-configured TPM PCR (if available).
+ *       The measurement list is append-only. No entry is
+ *       ever removed or changed during the boot-cycle.
+ */
+#include <linux/module.h>
+#include <linux/rculist.h>
+#include "ima.h"
+
+LIST_HEAD(ima_measurements);    /* list of all measurements */
+
+/* key: inode (before secure-hashing a file) */
+struct ima_h_table ima_htable = {
+        .len = ATOMIC_LONG_INIT(0),
+        .violations = ATOMIC_LONG_INIT(0),
+        .queue[0 ... IMA_MEASURE_HTABLE_SIZE - 1] = HLIST_HEAD_INIT
+};
+
+/* mutex protects atomicity of extending measurement list
+ * and extending the TPM PCR aggregate. Since tpm_extend can take
+ * long (and the tpm driver uses a mutex), we can't use the spinlock.
+ */
+static DEFINE_MUTEX(ima_extend_list_mutex);
+
+/* lookup up the digest value in the hash table, and return the entry */
+static struct ima_queue_entry *ima_lookup_digest_entry(u8 *digest_value)
+{
+        struct ima_queue_entry *qe, *ret = NULL;
+        unsigned int key;
+        struct hlist_node *pos;
+        int rc;
+
+        key = ima_hash_key(digest_value);
+        rcu_read_lock();
+        hlist_for_each_entry_rcu(qe, pos, &ima_htable.queue[key], hnext) {
+                rc = memcmp(qe->entry->digest, digest_value, IMA_DIGEST_SIZE);
+                if (rc == 0) {
+                        ret = qe;
+                        break;
+                }
+        }
+        rcu_read_unlock();
+        return ret;
+}
+
+/* ima_add_template_entry helper function:
+ * - Add template entry to measurement list and hash table.
+ *
+ * (Called with ima_extend_list_mutex held.)
+ */
+static int ima_add_digest_entry(struct ima_template_entry *entry)
+{
+        struct ima_queue_entry *qe;
+        unsigned int key;
+
+        qe = kmalloc(sizeof(*qe), GFP_KERNEL);
+        if (qe == NULL) {
+                pr_err("OUT OF MEMORY ERROR creating queue entry.\n");
+                return -ENOMEM;
+        }
+        qe->entry = entry;
+
+        INIT_LIST_HEAD(&qe->later);
+        list_add_tail_rcu(&qe->later, &ima_measurements);
+
+        atomic_long_inc(&ima_htable.len);
+        key = ima_hash_key(entry->digest);
+        hlist_add_head_rcu(&qe->hnext, &ima_htable.queue[key]);
+        return 0;
+}
+
+static int ima_pcr_extend(const u8 *hash)
+{
+        int result = 0;
+
+        if (!ima_used_chip)
+                return result;
+
+        result = tpm_pcr_extend(TPM_ANY_NUM, CONFIG_IMA_MEASURE_PCR_IDX, hash);
+        if (result != 0)
+                pr_err("Error Communicating to TPM chip\n");
+        return result;
+}
+
+/* Add template entry to the measurement list and hash table,
+ * and extend the pcr.
+ */
+int ima_add_template_entry(struct ima_template_entry *entry, int violation,
+                           const char *op, struct inode *inode)
+{
+        u8 digest[IMA_DIGEST_SIZE];
+        const char *audit_cause = "hash_added";
+        int audit_info = 1;
+        int result = 0;
+
+        mutex_lock(&ima_extend_list_mutex);
+        if (!violation) {
+                memcpy(digest, entry->digest, sizeof digest);
+                if (ima_lookup_digest_entry(digest)) {
+                        audit_cause = "hash_exists";
+                        goto out;
+                }
+        }
+
+        result = ima_add_digest_entry(entry);
+        if (result < 0) {
+                audit_cause = "ENOMEM";
+                audit_info = 0;
+                goto out;
+        }
+
+        if (violation)          /* invalidate pcr */
+                memset(digest, 0xff, sizeof digest);
+
+        result = ima_pcr_extend(digest);
+        if (result != 0) {
+                audit_cause = "TPM error";
+                audit_info = 0;
+        }
+out:
+        mutex_unlock(&ima_extend_list_mutex);
+        integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode, entry->template_name,
+                            op, audit_cause, result, audit_info);
+        return result;
+}