// SPDX-License-Identifier: GPL-2.0-only/* * 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> * * 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/rculist.h>#include <linux/slab.h>#include "ima.h" #define AUDIT_CAUSE_LEN_MAX 32 /* pre-allocated array of tpm_digest structures to extend a PCR */static struct tpm_digest *digests; LIST_HEAD(ima_measurements);	/* list of all measurements */#ifdef CONFIG_IMA_KEXECstatic unsigned long binary_runtime_size;#elsestatic unsigned long binary_runtime_size = ULONG_MAX;#endif /* 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,						       int pcr){	struct ima_queue_entry *qe, *ret = NULL;	unsigned int key;	int rc; 	key = ima_hash_key(digest_value);	rcu_read_lock();	hlist_for_each_entry_rcu(qe, &ima_htable.queue[key], hnext) {		rc = memcmp(qe->entry->digests[ima_hash_algo_idx].digest,			    digest_value, hash_digest_size[ima_hash_algo]);		if ((rc == 0) && (qe->entry->pcr == pcr)) {			ret = qe;			break;		}	}	rcu_read_unlock();	return ret;} /* * Calculate the memory required for serializing a single * binary_runtime_measurement list entry, which contains a * couple of variable length fields (e.g template name and data). */static int get_binary_runtime_size(struct ima_template_entry *entry){	int size = 0; 	size += sizeof(u32);	/* pcr */	size += TPM_DIGEST_SIZE;	size += sizeof(int);	/* template name size field */	size += strlen(entry->template_desc->name);	size += sizeof(entry->template_data_len);	size += entry->template_data_len;	return size;} /* ima_add_template_entry helper function: * - Add template entry to the measurement list and hash table, for *   all entries except those carried across kexec. * * (Called with ima_extend_list_mutex held.) */static int ima_add_digest_entry(struct ima_template_entry *entry,				bool update_htable){	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);	if (update_htable) {		key = ima_hash_key(entry->digests[ima_hash_algo_idx].digest);		hlist_add_head_rcu(&qe->hnext, &ima_htable.queue[key]);	} 	if (binary_runtime_size != ULONG_MAX) {		int size; 		size = get_binary_runtime_size(entry);		binary_runtime_size = (binary_runtime_size < ULONG_MAX - size) ?		     binary_runtime_size + size : ULONG_MAX;	}	return 0;} /* * Return the amount of memory required for serializing the * entire binary_runtime_measurement list, including the ima_kexec_hdr * structure. */unsigned long ima_get_binary_runtime_size(void){	if (binary_runtime_size >= (ULONG_MAX - sizeof(struct ima_kexec_hdr)))		return ULONG_MAX;	else		return binary_runtime_size + sizeof(struct ima_kexec_hdr);}; static int ima_pcr_extend(struct tpm_digest *digests_arg, int pcr){	int result = 0; 	if (!ima_tpm_chip)		return result; 	result = tpm_pcr_extend(ima_tpm_chip, pcr, digests_arg);	if (result != 0)		pr_err("Error Communicating to TPM chip, result: %d\n", result);	return result;} /* * Add template entry to the measurement list and hash table, and * extend the pcr. * * On systems which support carrying the IMA measurement list across * kexec, maintain the total memory size required for serializing the * binary_runtime_measurements. */int ima_add_template_entry(struct ima_template_entry *entry, int violation,			   const char *op, struct inode *inode,			   const unsigned char *filename){	u8 *digest = entry->digests[ima_hash_algo_idx].digest;	struct tpm_digest *digests_arg = entry->digests;	const char *audit_cause = "hash_added";	char tpm_audit_cause[AUDIT_CAUSE_LEN_MAX];	int audit_info = 1;	int result = 0, tpmresult = 0; 	mutex_lock(&ima_extend_list_mutex);	if (!violation) {		if (ima_lookup_digest_entry(digest, entry->pcr)) {			audit_cause = "hash_exists";			result = -EEXIST;			goto out;		}	} 	result = ima_add_digest_entry(entry, 1);	if (result < 0) {		audit_cause = "ENOMEM";		audit_info = 0;		goto out;	} 	if (violation)		/* invalidate pcr */		digests_arg = digests; 	tpmresult = ima_pcr_extend(digests_arg, entry->pcr);	if (tpmresult != 0) {		snprintf(tpm_audit_cause, AUDIT_CAUSE_LEN_MAX, "TPM_error(%d)",			 tpmresult);		audit_cause = tpm_audit_cause;		audit_info = 0;	}out:	mutex_unlock(&ima_extend_list_mutex);	integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode, filename,			    op, audit_cause, result, audit_info);	return result;} int ima_restore_measurement_entry(struct ima_template_entry *entry){	int result = 0; 	mutex_lock(&ima_extend_list_mutex);	result = ima_add_digest_entry(entry, 0);	mutex_unlock(&ima_extend_list_mutex);	return result;} int __init ima_init_digests(void){	u16 digest_size;	u16 crypto_id;	int i; 	if (!ima_tpm_chip)		return 0; 	digests = kcalloc(ima_tpm_chip->nr_allocated_banks, sizeof(*digests),			  GFP_NOFS);	if (!digests)		return -ENOMEM; 	for (i = 0; i < ima_tpm_chip->nr_allocated_banks; i++) {		digests[i].alg_id = ima_tpm_chip->allocated_banks[i].alg_id;		digest_size = ima_tpm_chip->allocated_banks[i].digest_size;		crypto_id = ima_tpm_chip->allocated_banks[i].crypto_id; 		/* for unmapped TPM algorithms digest is still a padded SHA1 */		if (crypto_id == HASH_ALGO__LAST)			digest_size = SHA1_DIGEST_SIZE; 		memset(digests[i].digest, 0xff, digest_size);	} 	return 0;}