Exemplo n.º 1
0
static int process_measurement(struct file *file, const char *filename,
			       int mask, int function)
{
	struct inode *inode = file_inode(file);
	struct integrity_iint_cache *iint;
	struct ima_template_desc *template_desc = ima_template_desc_current();
	char *pathbuf = NULL;
	const char *pathname = NULL;
	int rc = -ENOMEM, action, must_appraise, _func;
	struct evm_ima_xattr_data *xattr_value = NULL, **xattr_ptr = NULL;
	int xattr_len = 0;

	if (!ima_initialized || !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(inode, mask, function);
	if (!action)
		return 0;

	must_appraise = action & IMA_APPRAISE;

	/*  Is the appraise rule hook specific?  */
	_func = (action & IMA_FILE_APPRAISE) ? FILE_CHECK : function;

	mutex_lock(&inode->i_mutex);

	iint = integrity_inode_get(inode);
	if (!iint)
		goto out;

	/* 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) >> 1);

	/* Nothing to do, just return existing appraised status */
	if (!action) {
		if (must_appraise)
			rc = ima_get_cache_status(iint, _func);
		goto out_digsig;
	}

	if (strcmp(template_desc->name, IMA_TEMPLATE_IMA_NAME) == 0) {
		if (action & IMA_APPRAISE_SUBMASK)
			xattr_ptr = &xattr_value;
	} else
		xattr_ptr = &xattr_value;

	rc = ima_collect_measurement(iint, file, xattr_ptr, &xattr_len);
	if (rc != 0) {
		if (file->f_flags & O_DIRECT)
			rc = (iint->flags & IMA_PERMIT_DIRECTIO) ? 0 : -EACCES;
		goto out_digsig;
	}

	pathname = !filename ? ima_d_path(&file->f_path, &pathbuf) : filename;
	if (!pathname)
		pathname = (const char *)file->f_dentry->d_name.name;

	if (action & IMA_MEASURE)
		ima_store_measurement(iint, file, pathname,
				      xattr_value, xattr_len);
	if (action & IMA_APPRAISE_SUBMASK)
		rc = ima_appraise_measurement(_func, iint, file, pathname,
					      xattr_value, xattr_len);
	if (action & IMA_AUDIT)
		ima_audit_measurement(iint, pathname);
	kfree(pathbuf);
out_digsig:
	if ((mask & MAY_WRITE) && (iint->flags & IMA_DIGSIG))
		rc = -EACCES;
out:
	mutex_unlock(&inode->i_mutex);
	kfree(xattr_value);
	if ((rc && must_appraise) && (ima_appraise & IMA_APPRAISE_ENFORCE))
		return -EACCES;
	return 0;
}
Exemplo n.º 2
0
static int process_measurement(struct file *file, int mask, int function,
			       int opened)
{
	struct inode *inode = file_inode(file);
	struct integrity_iint_cache *iint = NULL;
	struct ima_template_desc *template_desc;
	char *pathbuf = NULL;
	const char *pathname = NULL;
	int rc = -ENOMEM, action, must_appraise;
	struct evm_ima_xattr_data *xattr_value = NULL, **xattr_ptr = NULL;
	int xattr_len = 0;
	bool violation_check;

	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(inode, mask, function);
	violation_check = ((function == FILE_CHECK || function == 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)
		function = FILE_CHECK;

	mutex_lock(&inode->i_mutex);

	if (action) {
		iint = integrity_inode_get(inode);
		if (!iint)
			goto out;
	}

	if (violation_check) {
		ima_rdwr_violation_check(file, iint, action & IMA_MEASURE,
					 &pathbuf, &pathname);
		if (!action) {
			rc = 0;
			goto out_free;
		}
	}

	/* 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) >> 1);

	/* Nothing to do, just return existing appraised status */
	if (!action) {
		if (must_appraise)
			rc = ima_get_cache_status(iint, function);
		goto out_digsig;
	}

	template_desc = ima_template_desc_current();
	if ((action & IMA_APPRAISE_SUBMASK) ||
		    strcmp(template_desc->name, IMA_TEMPLATE_IMA_NAME) != 0)
		xattr_ptr = &xattr_value;

	rc = ima_collect_measurement(iint, file, xattr_ptr, &xattr_len);
	if (rc != 0) {
		if (file->f_flags & O_DIRECT)
			rc = (iint->flags & IMA_PERMIT_DIRECTIO) ? 0 : -EACCES;
		goto out_digsig;
	}

	if (!pathname)	/* ima_rdwr_violation possibly pre-fetched */
		pathname = ima_d_path(&file->f_path, &pathbuf);

	if (action & IMA_MEASURE)
		ima_store_measurement(iint, file, pathname,
				      xattr_value, xattr_len);
	if (action & IMA_APPRAISE_SUBMASK)
		rc = ima_appraise_measurement(function, iint, file, pathname,
					      xattr_value, xattr_len, opened);
	if (action & IMA_AUDIT)
		ima_audit_measurement(iint, pathname);

out_digsig:
	if ((mask & MAY_WRITE) && (iint->flags & IMA_DIGSIG))
		rc = -EACCES;
	kfree(xattr_value);
out_free:
	if (pathbuf)
		__putname(pathbuf);
out:
	mutex_unlock(&inode->i_mutex);
	if ((rc && must_appraise) && (ima_appraise & IMA_APPRAISE_ENFORCE))
		return -EACCES;
	return 0;
}
Exemplo n.º 3
0
static int process_measurement(struct file *file, const struct cred *cred,
			       u32 secid, char *buf, loff_t size, int mask,
			       enum ima_hooks func, int opened)
{
	struct inode *inode = file_inode(file);
	struct integrity_iint_cache *iint = NULL;
	struct ima_template_desc *template_desc;
	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;
	int xattr_len = 0;
	bool violation_check;
	enum hash_algo hash_algo;

	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(inode, cred, secid, mask, func, &pcr);
	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_ACTION_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;
	}

	/* 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 = ima_get_cache_status(iint, func);
		goto out_locked;
	}

	template_desc = ima_template_desc_current();
	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);

	hash_algo = ima_get_hash_algo(xattr_value, xattr_len);

	rc = ima_collect_measurement(iint, file, buf, size, hash_algo);
	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, pcr);
	if (rc == 0 && (action & IMA_APPRAISE_SUBMASK)) {
		inode_lock(inode);
		rc = ima_appraise_measurement(func, iint, file, pathname,
					      xattr_value, xattr_len, opened);
		inode_unlock(inode);
	}
	if (action & IMA_AUDIT)
		ima_audit_measurement(iint, pathname);

	if ((file->f_flags & O_DIRECT) && (iint->flags & IMA_PERMIT_DIRECTIO))
		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);
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;
}