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author | David S. Miller <davem@davemloft.net> | 2009-03-26 15:23:24 -0700 |
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committer | David S. Miller <davem@davemloft.net> | 2009-03-26 15:23:24 -0700 |
commit | 08abe18af1f78ee80c3c3a5ac47c3e0ae0beadf6 (patch) | |
tree | 2be39bf8942edca1bcec735145e144a682ca9cd3 /security/integrity/ima/ima_queue.c | |
parent | f0de70f8bb56952f6e016a65a8a8d006918f5bf6 (diff) | |
parent | 0384e2959127a56d0640505d004d8dd92f9c29f5 (diff) |
Merge branch 'master' of /home/davem/src/GIT/linux-2.6/
Conflicts:
drivers/net/wimax/i2400m/usb-notif.c
Diffstat (limited to 'security/integrity/ima/ima_queue.c')
-rw-r--r-- | security/integrity/ima/ima_queue.c | 140 |
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 00000000000..7ec94314ac0 --- /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; +} |