Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1100 insertions, 0 deletions

diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
new file mode 100644
index 000000000..185666d90
--- /dev/null
+++ b/security/integrity/ima/ima_main.c
@@ -0,0 +1,1100 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Integrity Measurement Architecture
+ *
+ * Copyright (C) 2005,2006,2007,2008 IBM Corporation
+ *
+ * Authors:
+ * Reiner Sailer <sailer@watson.ibm.com>
+ * Serge Hallyn <serue@us.ibm.com>
+ * Kylene Hall <kylene@us.ibm.com>
+ * Mimi Zohar <zohar@us.ibm.com>
+ *
+ * File: ima_main.c
+ *	implements the IMA hooks: ima_bprm_check, ima_file_mmap,
+ *	and ima_file_check.
+ */
+
+#include <linux/module.h>
+#include <linux/file.h>
+#include <linux/binfmts.h>
+#include <linux/kernel_read_file.h>
+#include <linux/mount.h>
+#include <linux/mman.h>
+#include <linux/slab.h>
+#include <linux/xattr.h>
+#include <linux/ima.h>
+#include <linux/iversion.h>
+#include <linux/fs.h>
+#include <linux/iversion.h>
+
+#include "ima.h"
+
+#ifdef CONFIG_IMA_APPRAISE
+int ima_appraise = IMA_APPRAISE_ENFORCE;
+#else
+int ima_appraise;
+#endif
+
+int __ro_after_init ima_hash_algo = HASH_ALGO_SHA1;
+static int hash_setup_done;
+
+static struct notifier_block ima_lsm_policy_notifier = {
+	.notifier_call = ima_lsm_policy_change,
+};
+
+static int __init hash_setup(char *str)
+{
+	struct ima_template_desc *template_desc = ima_template_desc_current();
+	int i;
+
+	if (hash_setup_done)
+		return 1;
+
+	if (strcmp(template_desc->name, IMA_TEMPLATE_IMA_NAME) == 0) {
+		if (strncmp(str, "sha1", 4) == 0) {
+			ima_hash_algo = HASH_ALGO_SHA1;
+		} else if (strncmp(str, "md5", 3) == 0) {
+			ima_hash_algo = HASH_ALGO_MD5;
+		} else {
+			pr_err("invalid hash algorithm \"%s\" for template \"%s\"",
+				str, IMA_TEMPLATE_IMA_NAME);
+			return 1;
+		}
+		goto out;
+	}
+
+	i = match_string(hash_algo_name, HASH_ALGO__LAST, str);
+	if (i < 0) {
+		pr_err("invalid hash algorithm \"%s\"", str);
+		return 1;
+	}
+
+	ima_hash_algo = i;
+out:
+	hash_setup_done = 1;
+	return 1;
+}
+__setup("ima_hash=", hash_setup);
+
+enum hash_algo ima_get_current_hash_algo(void)
+{
+	return ima_hash_algo;
+}
+
+/* Prevent mmap'ing a file execute that is already mmap'ed write */
+static int mmap_violation_check(enum ima_hooks func, struct file *file,
+				char **pathbuf, const char **pathname,
+				char *filename)
+{
+	struct inode *inode;
+	int rc = 0;
+
+	if ((func == MMAP_CHECK) && mapping_writably_mapped(file->f_mapping)) {
+		rc = -ETXTBSY;
+		inode = file_inode(file);
+
+		if (!*pathbuf)	/* ima_rdwr_violation possibly pre-fetched */
+			*pathname = ima_d_path(&file->f_path, pathbuf,
+					       filename);
+		integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, *pathname,
+				    "mmap_file", "mmapped_writers", rc, 0);
+	}
+	return rc;
+}
+
+/*
+ * ima_rdwr_violation_check
+ *
+ * Only invalidate the PCR for measured files:
+ *	- Opening a file for write when already open for read,
+ *	  results in a time of measure, time of use (ToMToU) error.
+ *	- Opening a file for read when already open for write,
+ *	  could result in a file measurement error.
+ *
+ */
+static void ima_rdwr_violation_check(struct file *file,
+				     struct integrity_iint_cache *iint,
+				     int must_measure,
+				     char **pathbuf,
+				     const char **pathname,
+				     char *filename)
+{
+	struct inode *inode = file_inode(file);
+	fmode_t mode = file->f_mode;
+	bool send_tomtou = false, send_writers = false;
+
+	if (mode & FMODE_WRITE) {
+		if (atomic_read(&inode->i_readcount) && IS_IMA(inode)) {
+			if (!iint)
+				iint = integrity_iint_find(inode);
+			/* IMA_MEASURE is set from reader side */
+			if (iint && test_bit(IMA_MUST_MEASURE,
+						&iint->atomic_flags))
+				send_tomtou = true;
+		}
+	} else {
+		if (must_measure)
+			set_bit(IMA_MUST_MEASURE, &iint->atomic_flags);
+		if (inode_is_open_for_write(inode) && must_measure)
+			send_writers = true;
+	}
+
+	if (!send_tomtou && !send_writers)
+		return;
+
+	*pathname = ima_d_path(&file->f_path, pathbuf, filename);
+
+	if (send_tomtou)
+		ima_add_violation(file, *pathname, iint,
+				  "invalid_pcr", "ToMToU");
+	if (send_writers)
+		ima_add_violation(file, *pathname, iint,
+				  "invalid_pcr", "open_writers");
+}
+
+static void ima_check_last_writer(struct integrity_iint_cache *iint,
+				  struct inode *inode, struct file *file)
+{
+	fmode_t mode = file->f_mode;
+	bool update;
+
+	if (!(mode & FMODE_WRITE))
+		return;
+
+	mutex_lock(&iint->mutex);
+	if (atomic_read(&inode->i_writecount) == 1) {
+		update = test_and_clear_bit(IMA_UPDATE_XATTR,
+					    &iint->atomic_flags);
+		if (!IS_I_VERSION(inode) ||
+		    !inode_eq_iversion(inode, iint->version) ||
+		    (iint->flags & IMA_NEW_FILE)) {
+			iint->flags &= ~(IMA_DONE_MASK | IMA_NEW_FILE);
+			iint->measured_pcrs = 0;
+			if (update)
+				ima_update_xattr(iint, file);
+		}
+	}
+	mutex_unlock(&iint->mutex);
+}
+
+/**
+ * ima_file_free - called on __fput()
+ * @file: pointer to file structure being freed
+ *
+ * Flag files that changed, based on i_version
+ */
+void ima_file_free(struct file *file)
+{
+	struct inode *inode = file_inode(file);
+	struct integrity_iint_cache *iint;
+
+	if (!ima_policy_flag || !S_ISREG(inode->i_mode))
+		return;
+
+	iint = integrity_iint_find(inode);
+	if (!iint)
+		return;
+
+	ima_check_last_writer(iint, inode, file);
+}
+
+static int process_measurement(struct file *file, const struct cred *cred,
+			       u32 secid, char *buf, loff_t size, int mask,
+			       enum ima_hooks func)
+{
+	struct inode *backing_inode, *inode = file_inode(file);
+	struct integrity_iint_cache *iint = NULL;
+	struct ima_template_desc *template_desc = NULL;
+	char *pathbuf = NULL;
+	char filename[NAME_MAX];
+	const char *pathname = NULL;
+	int rc = 0, action, must_appraise = 0;
+	int pcr = CONFIG_IMA_MEASURE_PCR_IDX;
+	struct evm_ima_xattr_data *xattr_value = NULL;
+	struct modsig *modsig = NULL;
+	int xattr_len = 0;
+	bool violation_check;
+	enum hash_algo hash_algo;
+	unsigned int allowed_algos = 0;
+
+	if (!ima_policy_flag || !S_ISREG(inode->i_mode))
+		return 0;
+
+	/* Return an IMA_MEASURE, IMA_APPRAISE, IMA_AUDIT action
+	 * bitmask based on the appraise/audit/measurement policy.
+	 * Included is the appraise submask.
+	 */
+	action = ima_get_action(file_mnt_user_ns(file), inode, cred, secid,
+				mask, func, &pcr, &template_desc, NULL,
+				&allowed_algos);
+	violation_check = ((func == FILE_CHECK || func == MMAP_CHECK) &&
+			   (ima_policy_flag & IMA_MEASURE));
+	if (!action && !violation_check)
+		return 0;
+
+	must_appraise = action & IMA_APPRAISE;
+
+	/*  Is the appraise rule hook specific?  */
+	if (action & IMA_FILE_APPRAISE)
+		func = FILE_CHECK;
+
+	inode_lock(inode);
+
+	if (action) {
+		iint = integrity_inode_get(inode);
+		if (!iint)
+			rc = -ENOMEM;
+	}
+
+	if (!rc && violation_check)
+		ima_rdwr_violation_check(file, iint, action & IMA_MEASURE,
+					 &pathbuf, &pathname, filename);
+
+	inode_unlock(inode);
+
+	if (rc)
+		goto out;
+	if (!action)
+		goto out;
+
+	mutex_lock(&iint->mutex);
+
+	if (test_and_clear_bit(IMA_CHANGE_ATTR, &iint->atomic_flags))
+		/* reset appraisal flags if ima_inode_post_setattr was called */
+		iint->flags &= ~(IMA_APPRAISE | IMA_APPRAISED |
+				 IMA_APPRAISE_SUBMASK | IMA_APPRAISED_SUBMASK |
+				 IMA_NONACTION_FLAGS);
+
+	/*
+	 * Re-evaulate the file if either the xattr has changed or the
+	 * kernel has no way of detecting file change on the filesystem.
+	 * (Limited to privileged mounted filesystems.)
+	 */
+	if (test_and_clear_bit(IMA_CHANGE_XATTR, &iint->atomic_flags) ||
+	    ((inode->i_sb->s_iflags & SB_I_IMA_UNVERIFIABLE_SIGNATURE) &&
+	     !(inode->i_sb->s_iflags & SB_I_UNTRUSTED_MOUNTER) &&
+	     !(action & IMA_FAIL_UNVERIFIABLE_SIGS))) {
+		iint->flags &= ~IMA_DONE_MASK;
+		iint->measured_pcrs = 0;
+	}
+
+	/* Detect and re-evaluate changes made to the backing file. */
+	backing_inode = d_real_inode(file_dentry(file));
+	if (backing_inode != inode &&
+	    (action & IMA_DO_MASK) && (iint->flags & IMA_DONE_MASK)) {
+		if (!IS_I_VERSION(backing_inode) ||
+		    backing_inode->i_sb->s_dev != iint->real_dev ||
+		    backing_inode->i_ino != iint->real_ino ||
+		    !inode_eq_iversion(backing_inode, iint->version)) {
+			iint->flags &= ~IMA_DONE_MASK;
+			iint->measured_pcrs = 0;
+		}
+	}
+
+	/* Determine if already appraised/measured based on bitmask
+	 * (IMA_MEASURE, IMA_MEASURED, IMA_XXXX_APPRAISE, IMA_XXXX_APPRAISED,
+	 *  IMA_AUDIT, IMA_AUDITED)
+	 */
+	iint->flags |= action;
+	action &= IMA_DO_MASK;
+	action &= ~((iint->flags & (IMA_DONE_MASK ^ IMA_MEASURED)) >> 1);
+
+	/* If target pcr is already measured, unset IMA_MEASURE action */
+	if ((action & IMA_MEASURE) && (iint->measured_pcrs & (0x1 << pcr)))
+		action ^= IMA_MEASURE;
+
+	/* HASH sets the digital signature and update flags, nothing else */
+	if ((action & IMA_HASH) &&
+	    !(test_bit(IMA_DIGSIG, &iint->atomic_flags))) {
+		xattr_len = ima_read_xattr(file_dentry(file), &xattr_value);
+		if ((xattr_value && xattr_len > 2) &&
+		    (xattr_value->type == EVM_IMA_XATTR_DIGSIG))
+			set_bit(IMA_DIGSIG, &iint->atomic_flags);
+		iint->flags |= IMA_HASHED;
+		action ^= IMA_HASH;
+		set_bit(IMA_UPDATE_XATTR, &iint->atomic_flags);
+	}
+
+	/* Nothing to do, just return existing appraised status */
+	if (!action) {
+		if (must_appraise) {
+			rc = mmap_violation_check(func, file, &pathbuf,
+						  &pathname, filename);
+			if (!rc)
+				rc = ima_get_cache_status(iint, func);
+		}
+		goto out_locked;
+	}
+
+	if ((action & IMA_APPRAISE_SUBMASK) ||
+	    strcmp(template_desc->name, IMA_TEMPLATE_IMA_NAME) != 0) {
+		/* read 'security.ima' */
+		xattr_len = ima_read_xattr(file_dentry(file), &xattr_value);
+
+		/*
+		 * Read the appended modsig if allowed by the policy, and allow
+		 * an additional measurement list entry, if needed, based on the
+		 * template format and whether the file was already measured.
+		 */
+		if (iint->flags & IMA_MODSIG_ALLOWED) {
+			rc = ima_read_modsig(func, buf, size, &modsig);
+
+			if (!rc && ima_template_has_modsig(template_desc) &&
+			    iint->flags & IMA_MEASURED)
+				action |= IMA_MEASURE;
+		}
+	}
+
+	hash_algo = ima_get_hash_algo(xattr_value, xattr_len);
+
+	rc = ima_collect_measurement(iint, file, buf, size, hash_algo, modsig);
+	if (rc != 0 && rc != -EBADF && rc != -EINVAL)
+		goto out_locked;
+
+	if (!pathbuf)	/* ima_rdwr_violation possibly pre-fetched */
+		pathname = ima_d_path(&file->f_path, &pathbuf, filename);
+
+	if (action & IMA_MEASURE)
+		ima_store_measurement(iint, file, pathname,
+				      xattr_value, xattr_len, modsig, pcr,
+				      template_desc);
+	if (rc == 0 && (action & IMA_APPRAISE_SUBMASK)) {
+		rc = ima_check_blacklist(iint, modsig, pcr);
+		if (rc != -EPERM) {
+			inode_lock(inode);
+			rc = ima_appraise_measurement(func, iint, file,
+						      pathname, xattr_value,
+						      xattr_len, modsig);
+			inode_unlock(inode);
+		}
+		if (!rc)
+			rc = mmap_violation_check(func, file, &pathbuf,
+						  &pathname, filename);
+	}
+	if (action & IMA_AUDIT)
+		ima_audit_measurement(iint, pathname);
+
+	if ((file->f_flags & O_DIRECT) && (iint->flags & IMA_PERMIT_DIRECTIO))
+		rc = 0;
+
+	/* Ensure the digest was generated using an allowed algorithm */
+	if (rc == 0 && must_appraise && allowed_algos != 0 &&
+	    (allowed_algos & (1U << hash_algo)) == 0) {
+		rc = -EACCES;
+
+		integrity_audit_msg(AUDIT_INTEGRITY_DATA, file_inode(file),
+				    pathname, "collect_data",
+				    "denied-hash-algorithm", rc, 0);
+	}
+out_locked:
+	if ((mask & MAY_WRITE) && test_bit(IMA_DIGSIG, &iint->atomic_flags) &&
+	     !(iint->flags & IMA_NEW_FILE))
+		rc = -EACCES;
+	mutex_unlock(&iint->mutex);
+	kfree(xattr_value);
+	ima_free_modsig(modsig);
+out:
+	if (pathbuf)
+		__putname(pathbuf);
+	if (must_appraise) {
+		if (rc && (ima_appraise & IMA_APPRAISE_ENFORCE))
+			return -EACCES;
+		if (file->f_mode & FMODE_WRITE)
+			set_bit(IMA_UPDATE_XATTR, &iint->atomic_flags);
+	}
+	return 0;
+}
+
+/**
+ * ima_file_mmap - based on policy, collect/store measurement.
+ * @file: pointer to the file to be measured (May be NULL)
+ * @reqprot: protection requested by the application
+ * @prot: protection that will be applied by the kernel
+ * @flags: operational flags
+ *
+ * Measure files being mmapped executable based on the ima_must_measure()
+ * policy decision.
+ *
+ * On success return 0.  On integrity appraisal error, assuming the file
+ * is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
+ */
+int ima_file_mmap(struct file *file, unsigned long reqprot,
+		  unsigned long prot, unsigned long flags)
+{
+	u32 secid;
+
+	if (file && (prot & PROT_EXEC)) {
+		security_current_getsecid_subj(&secid);
+		return process_measurement(file, current_cred(), secid, NULL,
+					   0, MAY_EXEC, MMAP_CHECK);
+	}
+
+	return 0;
+}
+
+/**
+ * ima_file_mprotect - based on policy, limit mprotect change
+ * @vma: vm_area_struct protection is set to
+ * @prot: contains the protection that will be applied by the kernel.
+ *
+ * Files can be mmap'ed read/write and later changed to execute to circumvent
+ * IMA's mmap appraisal policy rules.  Due to locking issues (mmap semaphore
+ * would be taken before i_mutex), files can not be measured or appraised at
+ * this point.  Eliminate this integrity gap by denying the mprotect
+ * PROT_EXECUTE change, if an mmap appraise policy rule exists.
+ *
+ * On mprotect change success, return 0.  On failure, return -EACESS.
+ */
+int ima_file_mprotect(struct vm_area_struct *vma, unsigned long prot)
+{
+	struct ima_template_desc *template = NULL;
+	struct file *file;
+	char filename[NAME_MAX];
+	char *pathbuf = NULL;
+	const char *pathname = NULL;
+	struct inode *inode;
+	int result = 0;
+	int action;
+	u32 secid;
+	int pcr;
+
+	/* Is mprotect making an mmap'ed file executable? */
+	if (!(ima_policy_flag & IMA_APPRAISE) || !vma->vm_file ||
+	    !(prot & PROT_EXEC) || (vma->vm_flags & VM_EXEC))
+		return 0;
+
+	security_current_getsecid_subj(&secid);
+	inode = file_inode(vma->vm_file);
+	action = ima_get_action(file_mnt_user_ns(vma->vm_file), inode,
+				current_cred(), secid, MAY_EXEC, MMAP_CHECK,
+				&pcr, &template, NULL, NULL);
+
+	/* Is the mmap'ed file in policy? */
+	if (!(action & (IMA_MEASURE | IMA_APPRAISE_SUBMASK)))
+		return 0;
+
+	if (action & IMA_APPRAISE_SUBMASK)
+		result = -EPERM;
+
+	file = vma->vm_file;
+	pathname = ima_d_path(&file->f_path, &pathbuf, filename);
+	integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, pathname,
+			    "collect_data", "failed-mprotect", result, 0);
+	if (pathbuf)
+		__putname(pathbuf);
+
+	return result;
+}
+
+/**
+ * ima_bprm_check - based on policy, collect/store measurement.
+ * @bprm: contains the linux_binprm structure
+ *
+ * The OS protects against an executable file, already open for write,
+ * from being executed in deny_write_access() and an executable file,
+ * already open for execute, from being modified in get_write_access().
+ * So we can be certain that what we verify and measure here is actually
+ * what is being executed.
+ *
+ * On success return 0.  On integrity appraisal error, assuming the file
+ * is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
+ */
+int ima_bprm_check(struct linux_binprm *bprm)
+{
+	int ret;
+	u32 secid;
+
+	security_current_getsecid_subj(&secid);
+	ret = process_measurement(bprm->file, current_cred(), secid, NULL, 0,
+				  MAY_EXEC, BPRM_CHECK);
+	if (ret)
+		return ret;
+
+	security_cred_getsecid(bprm->cred, &secid);
+	return process_measurement(bprm->file, bprm->cred, secid, NULL, 0,
+				   MAY_EXEC, CREDS_CHECK);
+}
+
+/**
+ * ima_file_check - based on policy, collect/store measurement.
+ * @file: pointer to the file to be measured
+ * @mask: contains MAY_READ, MAY_WRITE, MAY_EXEC or MAY_APPEND
+ *
+ * Measure files based on the ima_must_measure() policy decision.
+ *
+ * On success return 0.  On integrity appraisal error, assuming the file
+ * is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
+ */
+int ima_file_check(struct file *file, int mask)
+{
+	u32 secid;
+
+	security_current_getsecid_subj(&secid);
+	return process_measurement(file, current_cred(), secid, NULL, 0,
+				   mask & (MAY_READ | MAY_WRITE | MAY_EXEC |
+					   MAY_APPEND), FILE_CHECK);
+}
+EXPORT_SYMBOL_GPL(ima_file_check);
+
+static int __ima_inode_hash(struct inode *inode, struct file *file, char *buf,
+			    size_t buf_size)
+{
+	struct integrity_iint_cache *iint = NULL, tmp_iint;
+	int rc, hash_algo;
+
+	if (ima_policy_flag) {
+		iint = integrity_iint_find(inode);
+		if (iint)
+			mutex_lock(&iint->mutex);
+	}
+
+	if ((!iint || !(iint->flags & IMA_COLLECTED)) && file) {
+		if (iint)
+			mutex_unlock(&iint->mutex);
+
+		memset(&tmp_iint, 0, sizeof(tmp_iint));
+		tmp_iint.inode = inode;
+		mutex_init(&tmp_iint.mutex);
+
+		rc = ima_collect_measurement(&tmp_iint, file, NULL, 0,
+					     ima_hash_algo, NULL);
+		if (rc < 0) {
+			/* ima_hash could be allocated in case of failure. */
+			if (rc != -ENOMEM)
+				kfree(tmp_iint.ima_hash);
+
+			return -EOPNOTSUPP;
+		}
+
+		iint = &tmp_iint;
+		mutex_lock(&iint->mutex);
+	}
+
+	if (!iint)
+		return -EOPNOTSUPP;
+
+	/*
+	 * ima_file_hash can be called when ima_collect_measurement has still
+	 * not been called, we might not always have a hash.
+	 */
+	if (!iint->ima_hash) {
+		mutex_unlock(&iint->mutex);
+		return -EOPNOTSUPP;
+	}
+
+	if (buf) {
+		size_t copied_size;
+
+		copied_size = min_t(size_t, iint->ima_hash->length, buf_size);
+		memcpy(buf, iint->ima_hash->digest, copied_size);
+	}
+	hash_algo = iint->ima_hash->algo;
+	mutex_unlock(&iint->mutex);
+
+	if (iint == &tmp_iint)
+		kfree(iint->ima_hash);
+
+	return hash_algo;
+}
+
+/**
+ * ima_file_hash - return a measurement of the file
+ * @file: pointer to the file
+ * @buf: buffer in which to store the hash
+ * @buf_size: length of the buffer
+ *
+ * On success, return the hash algorithm (as defined in the enum hash_algo).
+ * If buf is not NULL, this function also outputs the hash into buf.
+ * If the hash is larger than buf_size, then only buf_size bytes will be copied.
+ * It generally just makes sense to pass a buffer capable of holding the largest
+ * possible hash: IMA_MAX_DIGEST_SIZE.
+ * The file hash returned is based on the entire file, including the appended
+ * signature.
+ *
+ * If the measurement cannot be performed, return -EOPNOTSUPP.
+ * If the parameters are incorrect, return -EINVAL.
+ */
+int ima_file_hash(struct file *file, char *buf, size_t buf_size)
+{
+	if (!file)
+		return -EINVAL;
+
+	return __ima_inode_hash(file_inode(file), file, buf, buf_size);
+}
+EXPORT_SYMBOL_GPL(ima_file_hash);
+
+/**
+ * ima_inode_hash - return the stored measurement if the inode has been hashed
+ * and is in the iint cache.
+ * @inode: pointer to the inode
+ * @buf: buffer in which to store the hash
+ * @buf_size: length of the buffer
+ *
+ * On success, return the hash algorithm (as defined in the enum hash_algo).
+ * If buf is not NULL, this function also outputs the hash into buf.
+ * If the hash is larger than buf_size, then only buf_size bytes will be copied.
+ * It generally just makes sense to pass a buffer capable of holding the largest
+ * possible hash: IMA_MAX_DIGEST_SIZE.
+ * The hash returned is based on the entire contents, including the appended
+ * signature.
+ *
+ * If IMA is disabled or if no measurement is available, return -EOPNOTSUPP.
+ * If the parameters are incorrect, return -EINVAL.
+ */
+int ima_inode_hash(struct inode *inode, char *buf, size_t buf_size)
+{
+	if (!inode)
+		return -EINVAL;
+
+	return __ima_inode_hash(inode, NULL, buf, buf_size);
+}
+EXPORT_SYMBOL_GPL(ima_inode_hash);
+
+/**
+ * ima_post_create_tmpfile - mark newly created tmpfile as new
+ * @mnt_userns: user namespace of the mount the inode was found from
+ * @inode: inode of the newly created tmpfile
+ *
+ * No measuring, appraising or auditing of newly created tmpfiles is needed.
+ * Skip calling process_measurement(), but indicate which newly, created
+ * tmpfiles are in policy.
+ */
+void ima_post_create_tmpfile(struct user_namespace *mnt_userns,
+			     struct inode *inode)
+{
+	struct integrity_iint_cache *iint;
+	int must_appraise;
+
+	if (!ima_policy_flag || !S_ISREG(inode->i_mode))
+		return;
+
+	must_appraise = ima_must_appraise(mnt_userns, inode, MAY_ACCESS,
+					  FILE_CHECK);
+	if (!must_appraise)
+		return;
+
+	/* Nothing to do if we can't allocate memory */
+	iint = integrity_inode_get(inode);
+	if (!iint)
+		return;
+
+	/* needed for writing the security xattrs */
+	set_bit(IMA_UPDATE_XATTR, &iint->atomic_flags);
+	iint->ima_file_status = INTEGRITY_PASS;
+}
+
+/**
+ * ima_post_path_mknod - mark as a new inode
+ * @mnt_userns: user namespace of the mount the inode was found from
+ * @dentry: newly created dentry
+ *
+ * Mark files created via the mknodat syscall as new, so that the
+ * file data can be written later.
+ */
+void ima_post_path_mknod(struct user_namespace *mnt_userns,
+			 struct dentry *dentry)
+{
+	struct integrity_iint_cache *iint;
+	struct inode *inode = dentry->d_inode;
+	int must_appraise;
+
+	if (!ima_policy_flag || !S_ISREG(inode->i_mode))
+		return;
+
+	must_appraise = ima_must_appraise(mnt_userns, inode, MAY_ACCESS,
+					  FILE_CHECK);
+	if (!must_appraise)
+		return;
+
+	/* Nothing to do if we can't allocate memory */
+	iint = integrity_inode_get(inode);
+	if (!iint)
+		return;
+
+	/* needed for re-opening empty files */
+	iint->flags |= IMA_NEW_FILE;
+}
+
+/**
+ * ima_read_file - pre-measure/appraise hook decision based on policy
+ * @file: pointer to the file to be measured/appraised/audit
+ * @read_id: caller identifier
+ * @contents: whether a subsequent call will be made to ima_post_read_file()
+ *
+ * Permit reading a file based on policy. The policy rules are written
+ * in terms of the policy identifier.  Appraising the integrity of
+ * a file requires a file descriptor.
+ *
+ * For permission return 0, otherwise return -EACCES.
+ */
+int ima_read_file(struct file *file, enum kernel_read_file_id read_id,
+		  bool contents)
+{
+	enum ima_hooks func;
+	u32 secid;
+
+	/*
+	 * Do devices using pre-allocated memory run the risk of the
+	 * firmware being accessible to the device prior to the completion
+	 * of IMA's signature verification any more than when using two
+	 * buffers? It may be desirable to include the buffer address
+	 * in this API and walk all the dma_map_single() mappings to check.
+	 */
+
+	/*
+	 * There will be a call made to ima_post_read_file() with
+	 * a filled buffer, so we don't need to perform an extra
+	 * read early here.
+	 */
+	if (contents)
+		return 0;
+
+	/* Read entire file for all partial reads. */
+	func = read_idmap[read_id] ?: FILE_CHECK;
+	security_current_getsecid_subj(&secid);
+	return process_measurement(file, current_cred(), secid, NULL,
+				   0, MAY_READ, func);
+}
+
+const int read_idmap[READING_MAX_ID] = {
+	[READING_FIRMWARE] = FIRMWARE_CHECK,
+	[READING_MODULE] = MODULE_CHECK,
+	[READING_KEXEC_IMAGE] = KEXEC_KERNEL_CHECK,
+	[READING_KEXEC_INITRAMFS] = KEXEC_INITRAMFS_CHECK,
+	[READING_POLICY] = POLICY_CHECK
+};
+
+/**
+ * ima_post_read_file - in memory collect/appraise/audit measurement
+ * @file: pointer to the file to be measured/appraised/audit
+ * @buf: pointer to in memory file contents
+ * @size: size of in memory file contents
+ * @read_id: caller identifier
+ *
+ * Measure/appraise/audit in memory file based on policy.  Policy rules
+ * are written in terms of a policy identifier.
+ *
+ * On success return 0.  On integrity appraisal error, assuming the file
+ * is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
+ */
+int ima_post_read_file(struct file *file, void *buf, loff_t size,
+		       enum kernel_read_file_id read_id)
+{
+	enum ima_hooks func;
+	u32 secid;
+
+	/* permit signed certs */
+	if (!file && read_id == READING_X509_CERTIFICATE)
+		return 0;
+
+	if (!file || !buf || size == 0) { /* should never happen */
+		if (ima_appraise & IMA_APPRAISE_ENFORCE)
+			return -EACCES;
+		return 0;
+	}
+
+	func = read_idmap[read_id] ?: FILE_CHECK;
+	security_current_getsecid_subj(&secid);
+	return process_measurement(file, current_cred(), secid, buf, size,
+				   MAY_READ, func);
+}
+
+/**
+ * ima_load_data - appraise decision based on policy
+ * @id: kernel load data caller identifier
+ * @contents: whether the full contents will be available in a later
+ *	      call to ima_post_load_data().
+ *
+ * Callers of this LSM hook can not measure, appraise, or audit the
+ * data provided by userspace.  Enforce policy rules requiring a file
+ * signature (eg. kexec'ed kernel image).
+ *
+ * For permission return 0, otherwise return -EACCES.
+ */
+int ima_load_data(enum kernel_load_data_id id, bool contents)
+{
+	bool ima_enforce, sig_enforce;
+
+	ima_enforce =
+		(ima_appraise & IMA_APPRAISE_ENFORCE) == IMA_APPRAISE_ENFORCE;
+
+	switch (id) {
+	case LOADING_KEXEC_IMAGE:
+		if (IS_ENABLED(CONFIG_KEXEC_SIG)
+		    && arch_ima_get_secureboot()) {
+			pr_err("impossible to appraise a kernel image without a file descriptor; try using kexec_file_load syscall.\n");
+			return -EACCES;
+		}
+
+		if (ima_enforce && (ima_appraise & IMA_APPRAISE_KEXEC)) {
+			pr_err("impossible to appraise a kernel image without a file descriptor; try using kexec_file_load syscall.\n");
+			return -EACCES;	/* INTEGRITY_UNKNOWN */
+		}
+		break;
+	case LOADING_FIRMWARE:
+		if (ima_enforce && (ima_appraise & IMA_APPRAISE_FIRMWARE) && !contents) {
+			pr_err("Prevent firmware sysfs fallback loading.\n");
+			return -EACCES;	/* INTEGRITY_UNKNOWN */
+		}
+		break;
+	case LOADING_MODULE:
+		sig_enforce = is_module_sig_enforced();
+
+		if (ima_enforce && (!sig_enforce
+				    && (ima_appraise & IMA_APPRAISE_MODULES))) {
+			pr_err("impossible to appraise a module without a file descriptor. sig_enforce kernel parameter might help\n");
+			return -EACCES;	/* INTEGRITY_UNKNOWN */
+		}
+		break;
+	default:
+		break;
+	}
+	return 0;
+}
+
+/**
+ * ima_post_load_data - appraise decision based on policy
+ * @buf: pointer to in memory file contents
+ * @size: size of in memory file contents
+ * @load_id: kernel load data caller identifier
+ * @description: @load_id-specific description of contents
+ *
+ * Measure/appraise/audit in memory buffer based on policy.  Policy rules
+ * are written in terms of a policy identifier.
+ *
+ * On success return 0.  On integrity appraisal error, assuming the file
+ * is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
+ */
+int ima_post_load_data(char *buf, loff_t size,
+		       enum kernel_load_data_id load_id,
+		       char *description)
+{
+	if (load_id == LOADING_FIRMWARE) {
+		if ((ima_appraise & IMA_APPRAISE_FIRMWARE) &&
+		    (ima_appraise & IMA_APPRAISE_ENFORCE)) {
+			pr_err("Prevent firmware loading_store.\n");
+			return -EACCES; /* INTEGRITY_UNKNOWN */
+		}
+		return 0;
+	}
+
+	return 0;
+}
+
+/**
+ * process_buffer_measurement - Measure the buffer or the buffer data hash
+ * @mnt_userns:	user namespace of the mount the inode was found from
+ * @inode: inode associated with the object being measured (NULL for KEY_CHECK)
+ * @buf: pointer to the buffer that needs to be added to the log.
+ * @size: size of buffer(in bytes).
+ * @eventname: event name to be used for the buffer entry.
+ * @func: IMA hook
+ * @pcr: pcr to extend the measurement
+ * @func_data: func specific data, may be NULL
+ * @buf_hash: measure buffer data hash
+ * @digest: buffer digest will be written to
+ * @digest_len: buffer length
+ *
+ * Based on policy, either the buffer data or buffer data hash is measured
+ *
+ * Return: 0 if the buffer has been successfully measured, 1 if the digest
+ * has been written to the passed location but not added to a measurement entry,
+ * a negative value otherwise.
+ */
+int process_buffer_measurement(struct user_namespace *mnt_userns,
+			       struct inode *inode, const void *buf, int size,
+			       const char *eventname, enum ima_hooks func,
+			       int pcr, const char *func_data,
+			       bool buf_hash, u8 *digest, size_t digest_len)
+{
+	int ret = 0;
+	const char *audit_cause = "ENOMEM";
+	struct ima_template_entry *entry = NULL;
+	struct integrity_iint_cache iint = {};
+	struct ima_event_data event_data = {.iint = &iint,
+					    .filename = eventname,
+					    .buf = buf,
+					    .buf_len = size};
+	struct ima_template_desc *template;
+	struct ima_max_digest_data hash;
+	char digest_hash[IMA_MAX_DIGEST_SIZE];
+	int digest_hash_len = hash_digest_size[ima_hash_algo];
+	int violation = 0;
+	int action = 0;
+	u32 secid;
+
+	if (digest && digest_len < digest_hash_len)
+		return -EINVAL;
+
+	if (!ima_policy_flag && !digest)
+		return -ENOENT;
+
+	template = ima_template_desc_buf();
+	if (!template) {
+		ret = -EINVAL;
+		audit_cause = "ima_template_desc_buf";
+		goto out;
+	}
+
+	/*
+	 * Both LSM hooks and auxilary based buffer measurements are
+	 * based on policy.  To avoid code duplication, differentiate
+	 * between the LSM hooks and auxilary buffer measurements,
+	 * retrieving the policy rule information only for the LSM hook
+	 * buffer measurements.
+	 */
+	if (func) {
+		security_current_getsecid_subj(&secid);
+		action = ima_get_action(mnt_userns, inode, current_cred(),
+					secid, 0, func, &pcr, &template,
+					func_data, NULL);
+		if (!(action & IMA_MEASURE) && !digest)
+			return -ENOENT;
+	}
+
+	if (!pcr)
+		pcr = CONFIG_IMA_MEASURE_PCR_IDX;
+
+	iint.ima_hash = &hash.hdr;
+	iint.ima_hash->algo = ima_hash_algo;
+	iint.ima_hash->length = hash_digest_size[ima_hash_algo];
+
+	ret = ima_calc_buffer_hash(buf, size, iint.ima_hash);
+	if (ret < 0) {
+		audit_cause = "hashing_error";
+		goto out;
+	}
+
+	if (buf_hash) {
+		memcpy(digest_hash, hash.hdr.digest, digest_hash_len);
+
+		ret = ima_calc_buffer_hash(digest_hash, digest_hash_len,
+					   iint.ima_hash);
+		if (ret < 0) {
+			audit_cause = "hashing_error";
+			goto out;
+		}
+
+		event_data.buf = digest_hash;
+		event_data.buf_len = digest_hash_len;
+	}
+
+	if (digest)
+		memcpy(digest, iint.ima_hash->digest, digest_hash_len);
+
+	if (!ima_policy_flag || (func && !(action & IMA_MEASURE)))
+		return 1;
+
+	ret = ima_alloc_init_template(&event_data, &entry, template);
+	if (ret < 0) {
+		audit_cause = "alloc_entry";
+		goto out;
+	}
+
+	ret = ima_store_template(entry, violation, NULL, event_data.buf, pcr);
+	if (ret < 0) {
+		audit_cause = "store_entry";
+		ima_free_template_entry(entry);
+	}
+
+out:
+	if (ret < 0)
+		integrity_audit_message(AUDIT_INTEGRITY_PCR, NULL, eventname,
+					func_measure_str(func),
+					audit_cause, ret, 0, ret);
+
+	return ret;
+}
+
+/**
+ * ima_kexec_cmdline - measure kexec cmdline boot args
+ * @kernel_fd: file descriptor of the kexec kernel being loaded
+ * @buf: pointer to buffer
+ * @size: size of buffer
+ *
+ * Buffers can only be measured, not appraised.
+ */
+void ima_kexec_cmdline(int kernel_fd, const void *buf, int size)
+{
+	struct fd f;
+
+	if (!buf || !size)
+		return;
+
+	f = fdget(kernel_fd);
+	if (!f.file)
+		return;
+
+	process_buffer_measurement(file_mnt_user_ns(f.file), file_inode(f.file),
+				   buf, size, "kexec-cmdline", KEXEC_CMDLINE, 0,
+				   NULL, false, NULL, 0);
+	fdput(f);
+}
+
+/**
+ * ima_measure_critical_data - measure kernel integrity critical data
+ * @event_label: unique event label for grouping and limiting critical data
+ * @event_name: event name for the record in the IMA measurement list
+ * @buf: pointer to buffer data
+ * @buf_len: length of buffer data (in bytes)
+ * @hash: measure buffer data hash
+ * @digest: buffer digest will be written to
+ * @digest_len: buffer length
+ *
+ * Measure data critical to the integrity of the kernel into the IMA log
+ * and extend the pcr.  Examples of critical data could be various data
+ * structures, policies, and states stored in kernel memory that can
+ * impact the integrity of the system.
+ *
+ * Return: 0 if the buffer has been successfully measured, 1 if the digest
+ * has been written to the passed location but not added to a measurement entry,
+ * a negative value otherwise.
+ */
+int ima_measure_critical_data(const char *event_label,
+			      const char *event_name,
+			      const void *buf, size_t buf_len,
+			      bool hash, u8 *digest, size_t digest_len)
+{
+	if (!event_name || !event_label || !buf || !buf_len)
+		return -ENOPARAM;
+
+	return process_buffer_measurement(&init_user_ns, NULL, buf, buf_len,
+					  event_name, CRITICAL_DATA, 0,
+					  event_label, hash, digest,
+					  digest_len);
+}
+EXPORT_SYMBOL_GPL(ima_measure_critical_data);
+
+static int __init init_ima(void)
+{
+	int error;
+
+	ima_appraise_parse_cmdline();
+	ima_init_template_list();
+	hash_setup(CONFIG_IMA_DEFAULT_HASH);
+	error = ima_init();
+
+	if (error && strcmp(hash_algo_name[ima_hash_algo],
+			    CONFIG_IMA_DEFAULT_HASH) != 0) {
+		pr_info("Allocating %s failed, going to use default hash algorithm %s\n",
+			hash_algo_name[ima_hash_algo], CONFIG_IMA_DEFAULT_HASH);
+		hash_setup_done = 0;
+		hash_setup(CONFIG_IMA_DEFAULT_HASH);
+		error = ima_init();
+	}
+
+	if (error)
+		return error;
+
+	error = register_blocking_lsm_notifier(&ima_lsm_policy_notifier);
+	if (error)
+		pr_warn("Couldn't register LSM notifier, error %d\n", error);
+
+	if (!error)
+		ima_update_policy_flags();
+
+	return error;
+}
+
+late_initcall(init_ima);	/* Start IMA after the TPM is available */