v4.19.13 snapshot.
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
new file mode 100644
index 0000000..a02c5ac
--- /dev/null
+++ b/security/integrity/ima/ima_api.c
@@ -0,0 +1,377 @@
+/*
+ * Copyright (C) 2008 IBM Corporation
+ *
+ * Author: 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_api.c
+ * Implements must_appraise_or_measure, collect_measurement,
+ * appraise_measurement, store_measurement and store_template.
+ */
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/xattr.h>
+#include <linux/evm.h>
+#include <linux/iversion.h>
+
+#include "ima.h"
+
+/*
+ * ima_free_template_entry - free an existing template entry
+ */
+void ima_free_template_entry(struct ima_template_entry *entry)
+{
+ int i;
+
+ for (i = 0; i < entry->template_desc->num_fields; i++)
+ kfree(entry->template_data[i].data);
+
+ kfree(entry);
+}
+
+/*
+ * ima_alloc_init_template - create and initialize a new template entry
+ */
+int ima_alloc_init_template(struct ima_event_data *event_data,
+ struct ima_template_entry **entry)
+{
+ struct ima_template_desc *template_desc = ima_template_desc_current();
+ int i, result = 0;
+
+ *entry = kzalloc(sizeof(**entry) + template_desc->num_fields *
+ sizeof(struct ima_field_data), GFP_NOFS);
+ if (!*entry)
+ return -ENOMEM;
+
+ (*entry)->template_desc = template_desc;
+ for (i = 0; i < template_desc->num_fields; i++) {
+ struct ima_template_field *field = template_desc->fields[i];
+ u32 len;
+
+ result = field->field_init(event_data,
+ &((*entry)->template_data[i]));
+ if (result != 0)
+ goto out;
+
+ len = (*entry)->template_data[i].len;
+ (*entry)->template_data_len += sizeof(len);
+ (*entry)->template_data_len += len;
+ }
+ return 0;
+out:
+ ima_free_template_entry(*entry);
+ *entry = NULL;
+ return result;
+}
+
+/*
+ * ima_store_template - store ima template measurements
+ *
+ * Calculate the hash of a template entry, add the template entry
+ * to an ordered list of measurement entries maintained inside the kernel,
+ * and also update the aggregate integrity value (maintained inside the
+ * configured TPM PCR) over the hashes of the current list of measurement
+ * entries.
+ *
+ * Applications retrieve the current kernel-held measurement list through
+ * the securityfs entries in /sys/kernel/security/ima. The signed aggregate
+ * TPM PCR (called quote) can be retrieved using a TPM user space library
+ * and is used to validate the measurement list.
+ *
+ * Returns 0 on success, error code otherwise
+ */
+int ima_store_template(struct ima_template_entry *entry,
+ int violation, struct inode *inode,
+ const unsigned char *filename, int pcr)
+{
+ static const char op[] = "add_template_measure";
+ static const char audit_cause[] = "hashing_error";
+ char *template_name = entry->template_desc->name;
+ int result;
+ struct {
+ struct ima_digest_data hdr;
+ char digest[TPM_DIGEST_SIZE];
+ } hash;
+
+ if (!violation) {
+ int num_fields = entry->template_desc->num_fields;
+
+ /* this function uses default algo */
+ hash.hdr.algo = HASH_ALGO_SHA1;
+ result = ima_calc_field_array_hash(&entry->template_data[0],
+ entry->template_desc,
+ num_fields, &hash.hdr);
+ if (result < 0) {
+ integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode,
+ template_name, op,
+ audit_cause, result, 0);
+ return result;
+ }
+ memcpy(entry->digest, hash.hdr.digest, hash.hdr.length);
+ }
+ entry->pcr = pcr;
+ result = ima_add_template_entry(entry, violation, op, inode, filename);
+ return result;
+}
+
+/*
+ * ima_add_violation - add violation to measurement list.
+ *
+ * Violations are flagged in the measurement list with zero hash values.
+ * By extending the PCR with 0xFF's instead of with zeroes, the PCR
+ * value is invalidated.
+ */
+void ima_add_violation(struct file *file, const unsigned char *filename,
+ struct integrity_iint_cache *iint,
+ const char *op, const char *cause)
+{
+ struct ima_template_entry *entry;
+ struct inode *inode = file_inode(file);
+ struct ima_event_data event_data = {iint, file, filename, NULL, 0,
+ cause};
+ int violation = 1;
+ int result;
+
+ /* can overflow, only indicator */
+ atomic_long_inc(&ima_htable.violations);
+
+ result = ima_alloc_init_template(&event_data, &entry);
+ if (result < 0) {
+ result = -ENOMEM;
+ goto err_out;
+ }
+ result = ima_store_template(entry, violation, inode,
+ filename, CONFIG_IMA_MEASURE_PCR_IDX);
+ if (result < 0)
+ ima_free_template_entry(entry);
+err_out:
+ integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode, filename,
+ op, cause, result, 0);
+}
+
+/**
+ * ima_get_action - appraise & measure decision based on policy.
+ * @inode: pointer to inode to measure
+ * @cred: pointer to credentials structure to validate
+ * @secid: secid of the task being validated
+ * @mask: contains the permission mask (MAY_READ, MAY_WRITE, MAY_EXEC,
+ * MAY_APPEND)
+ * @func: caller identifier
+ * @pcr: pointer filled in if matched measure policy sets pcr=
+ *
+ * The policy is defined in terms of keypairs:
+ * subj=, obj=, type=, func=, mask=, fsmagic=
+ * subj,obj, and type: are LSM specific.
+ * func: FILE_CHECK | BPRM_CHECK | CREDS_CHECK | MMAP_CHECK | MODULE_CHECK
+ * mask: contains the permission mask
+ * fsmagic: hex value
+ *
+ * Returns IMA_MEASURE, IMA_APPRAISE mask.
+ *
+ */
+int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid,
+ int mask, enum ima_hooks func, int *pcr)
+{
+ int flags = IMA_MEASURE | IMA_AUDIT | IMA_APPRAISE | IMA_HASH;
+
+ flags &= ima_policy_flag;
+
+ return ima_match_policy(inode, cred, secid, func, mask, flags, pcr);
+}
+
+/*
+ * ima_collect_measurement - collect file measurement
+ *
+ * Calculate the file hash, if it doesn't already exist,
+ * storing the measurement and i_version in the iint.
+ *
+ * Must be called with iint->mutex held.
+ *
+ * Return 0 on success, error code otherwise
+ */
+int ima_collect_measurement(struct integrity_iint_cache *iint,
+ struct file *file, void *buf, loff_t size,
+ enum hash_algo algo)
+{
+ const char *audit_cause = "failed";
+ struct inode *inode = file_inode(file);
+ const char *filename = file->f_path.dentry->d_name.name;
+ int result = 0;
+ int length;
+ void *tmpbuf;
+ u64 i_version;
+ struct {
+ struct ima_digest_data hdr;
+ char digest[IMA_MAX_DIGEST_SIZE];
+ } hash;
+
+ if (iint->flags & IMA_COLLECTED)
+ goto out;
+
+ /*
+ * Dectecting file change is based on i_version. On filesystems
+ * which do not support i_version, support is limited to an initial
+ * measurement/appraisal/audit.
+ */
+ i_version = inode_query_iversion(inode);
+ hash.hdr.algo = algo;
+
+ /* Initialize hash digest to 0's in case of failure */
+ memset(&hash.digest, 0, sizeof(hash.digest));
+
+ if (buf)
+ result = ima_calc_buffer_hash(buf, size, &hash.hdr);
+ else
+ result = ima_calc_file_hash(file, &hash.hdr);
+
+ if (result && result != -EBADF && result != -EINVAL)
+ goto out;
+
+ length = sizeof(hash.hdr) + hash.hdr.length;
+ tmpbuf = krealloc(iint->ima_hash, length, GFP_NOFS);
+ if (!tmpbuf) {
+ result = -ENOMEM;
+ goto out;
+ }
+
+ iint->ima_hash = tmpbuf;
+ memcpy(iint->ima_hash, &hash, length);
+ iint->version = i_version;
+
+ /* Possibly temporary failure due to type of read (eg. O_DIRECT) */
+ if (!result)
+ iint->flags |= IMA_COLLECTED;
+out:
+ if (result) {
+ if (file->f_flags & O_DIRECT)
+ audit_cause = "failed(directio)";
+
+ integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode,
+ filename, "collect_data", audit_cause,
+ result, 0);
+ }
+ return result;
+}
+
+/*
+ * ima_store_measurement - store file measurement
+ *
+ * Create an "ima" template and then store the template by calling
+ * ima_store_template.
+ *
+ * We only get here if the inode has not already been measured,
+ * but the measurement could already exist:
+ * - multiple copies of the same file on either the same or
+ * different filesystems.
+ * - the inode was previously flushed as well as the iint info,
+ * containing the hashing info.
+ *
+ * Must be called with iint->mutex held.
+ */
+void ima_store_measurement(struct integrity_iint_cache *iint,
+ struct file *file, const unsigned char *filename,
+ struct evm_ima_xattr_data *xattr_value,
+ int xattr_len, int pcr)
+{
+ static const char op[] = "add_template_measure";
+ static const char audit_cause[] = "ENOMEM";
+ int result = -ENOMEM;
+ struct inode *inode = file_inode(file);
+ struct ima_template_entry *entry;
+ struct ima_event_data event_data = {iint, file, filename, xattr_value,
+ xattr_len, NULL};
+ int violation = 0;
+
+ if (iint->measured_pcrs & (0x1 << pcr))
+ return;
+
+ result = ima_alloc_init_template(&event_data, &entry);
+ if (result < 0) {
+ integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode, filename,
+ op, audit_cause, result, 0);
+ return;
+ }
+
+ result = ima_store_template(entry, violation, inode, filename, pcr);
+ if ((!result || result == -EEXIST) && !(file->f_flags & O_DIRECT)) {
+ iint->flags |= IMA_MEASURED;
+ iint->measured_pcrs |= (0x1 << pcr);
+ }
+ if (result < 0)
+ ima_free_template_entry(entry);
+}
+
+void ima_audit_measurement(struct integrity_iint_cache *iint,
+ const unsigned char *filename)
+{
+ struct audit_buffer *ab;
+ char *hash;
+ const char *algo_name = hash_algo_name[iint->ima_hash->algo];
+ int i;
+
+ if (iint->flags & IMA_AUDITED)
+ return;
+
+ hash = kzalloc((iint->ima_hash->length * 2) + 1, GFP_KERNEL);
+ if (!hash)
+ return;
+
+ for (i = 0; i < iint->ima_hash->length; i++)
+ hex_byte_pack(hash + (i * 2), iint->ima_hash->digest[i]);
+ hash[i * 2] = '\0';
+
+ ab = audit_log_start(audit_context(), GFP_KERNEL,
+ AUDIT_INTEGRITY_RULE);
+ if (!ab)
+ goto out;
+
+ audit_log_format(ab, "file=");
+ audit_log_untrustedstring(ab, filename);
+ audit_log_format(ab, " hash=\"%s:%s\"", algo_name, hash);
+
+ audit_log_task_info(ab, current);
+ audit_log_end(ab);
+
+ iint->flags |= IMA_AUDITED;
+out:
+ kfree(hash);
+ return;
+}
+
+/*
+ * ima_d_path - return a pointer to the full pathname
+ *
+ * Attempt to return a pointer to the full pathname for use in the
+ * IMA measurement list, IMA audit records, and auditing logs.
+ *
+ * On failure, return a pointer to a copy of the filename, not dname.
+ * Returning a pointer to dname, could result in using the pointer
+ * after the memory has been freed.
+ */
+const char *ima_d_path(const struct path *path, char **pathbuf, char *namebuf)
+{
+ char *pathname = NULL;
+
+ *pathbuf = __getname();
+ if (*pathbuf) {
+ pathname = d_absolute_path(path, *pathbuf, PATH_MAX);
+ if (IS_ERR(pathname)) {
+ __putname(*pathbuf);
+ *pathbuf = NULL;
+ pathname = NULL;
+ }
+ }
+
+ if (!pathname) {
+ strlcpy(namebuf, path->dentry->d_name.name, NAME_MAX);
+ pathname = namebuf;
+ }
+
+ return pathname;
+}