Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

Pull security subsystem updates from James Morris:
 "Highlights:

   - Integrity: add local fs integrity verification to detect offline
     attacks
   - Integrity: add digital signature verification
   - Simple stacking of Yama with other LSMs (per LSS discussions)
   - IBM vTPM support on ppc64
   - Add new driver for Infineon I2C TIS TPM
   - Smack: add rule revocation for subject labels"

Fixed conflicts with the user namespace support in kernel/auditsc.c and
security/integrity/ima/ima_policy.c.

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (39 commits)
  Documentation: Update git repository URL for Smack userland tools
  ima: change flags container data type
  Smack: setprocattr memory leak fix
  Smack: implement revoking all rules for a subject label
  Smack: remove task_wait() hook.
  ima: audit log hashes
  ima: generic IMA action flag handling
  ima: rename ima_must_appraise_or_measure
  audit: export audit_log_task_info
  tpm: fix tpm_acpi sparse warning on different address spaces
  samples/seccomp: fix 31 bit build on s390
  ima: digital signature verification support
  ima: add support for different security.ima data types
  ima: add ima_inode_setxattr/removexattr function and calls
  ima: add inode_post_setattr call
  ima: replace iint spinblock with rwlock/read_lock
  ima: allocating iint improvements
  ima: add appraise action keywords and default rules
  ima: integrity appraisal extension
  vfs: move ima_file_free before releasing the file
  ...

1 files changed, 263 insertions, 0 deletions

diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
new file mode 100644
index 00000000000..0aa43bde441
--- /dev/null
+++ b/security/integrity/ima/ima_appraise.c
@@ -0,0 +1,263 @@
+/*
+ * Copyright (C) 2011 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.
+ */
+#include <linux/module.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/xattr.h>
+#include <linux/magic.h>
+#include <linux/ima.h>
+#include <linux/evm.h>
+
+#include "ima.h"
+
+static int __init default_appraise_setup(char *str)
+{
+	if (strncmp(str, "off", 3) == 0)
+		ima_appraise = 0;
+	else if (strncmp(str, "fix", 3) == 0)
+		ima_appraise = IMA_APPRAISE_FIX;
+	return 1;
+}
+
+__setup("ima_appraise=", default_appraise_setup);
+
+/*
+ * ima_must_appraise - set appraise flag
+ *
+ * Return 1 to appraise
+ */
+int ima_must_appraise(struct inode *inode, enum ima_hooks func, int mask)
+{
+	if (!ima_appraise)
+		return 0;
+
+	return ima_match_policy(inode, func, mask, IMA_APPRAISE);
+}
+
+static void ima_fix_xattr(struct dentry *dentry,
+			  struct integrity_iint_cache *iint)
+{
+	iint->ima_xattr.type = IMA_XATTR_DIGEST;
+	__vfs_setxattr_noperm(dentry, XATTR_NAME_IMA, (u8 *)&iint->ima_xattr,
+			      sizeof iint->ima_xattr, 0);
+}
+
+/*
+ * ima_appraise_measurement - appraise file measurement
+ *
+ * Call evm_verifyxattr() to verify the integrity of 'security.ima'.
+ * Assuming success, compare the xattr hash with the collected measurement.
+ *
+ * Return 0 on success, error code otherwise
+ */
+int ima_appraise_measurement(struct integrity_iint_cache *iint,
+			     struct file *file, const unsigned char *filename)
+{
+	struct dentry *dentry = file->f_dentry;
+	struct inode *inode = dentry->d_inode;
+	struct evm_ima_xattr_data *xattr_value = NULL;
+	enum integrity_status status = INTEGRITY_UNKNOWN;
+	const char *op = "appraise_data";
+	char *cause = "unknown";
+	int rc;
+
+	if (!ima_appraise)
+		return 0;
+	if (!inode->i_op->getxattr)
+		return INTEGRITY_UNKNOWN;
+
+	if (iint->flags & IMA_APPRAISED)
+		return iint->ima_status;
+
+	rc = vfs_getxattr_alloc(dentry, XATTR_NAME_IMA, (char **)&xattr_value,
+				0, GFP_NOFS);
+	if (rc <= 0) {
+		if (rc && rc != -ENODATA)
+			goto out;
+
+		cause = "missing-hash";
+		status =
+		    (inode->i_size == 0) ? INTEGRITY_PASS : INTEGRITY_NOLABEL;
+		goto out;
+	}
+
+	status = evm_verifyxattr(dentry, XATTR_NAME_IMA, xattr_value, rc, iint);
+	if ((status != INTEGRITY_PASS) && (status != INTEGRITY_UNKNOWN)) {
+		if ((status == INTEGRITY_NOLABEL)
+		    || (status == INTEGRITY_NOXATTRS))
+			cause = "missing-HMAC";
+		else if (status == INTEGRITY_FAIL)
+			cause = "invalid-HMAC";
+		goto out;
+	}
+
+	switch (xattr_value->type) {
+	case IMA_XATTR_DIGEST:
+		rc = memcmp(xattr_value->digest, iint->ima_xattr.digest,
+			    IMA_DIGEST_SIZE);
+		if (rc) {
+			cause = "invalid-hash";
+			status = INTEGRITY_FAIL;
+			print_hex_dump_bytes("security.ima: ", DUMP_PREFIX_NONE,
+					     xattr_value, sizeof(*xattr_value));
+			print_hex_dump_bytes("collected: ", DUMP_PREFIX_NONE,
+					     (u8 *)&iint->ima_xattr,
+					     sizeof iint->ima_xattr);
+			break;
+		}
+		status = INTEGRITY_PASS;
+		break;
+	case EVM_IMA_XATTR_DIGSIG:
+		iint->flags |= IMA_DIGSIG;
+		rc = integrity_digsig_verify(INTEGRITY_KEYRING_IMA,
+					     xattr_value->digest, rc - 1,
+					     iint->ima_xattr.digest,
+					     IMA_DIGEST_SIZE);
+		if (rc == -EOPNOTSUPP) {
+			status = INTEGRITY_UNKNOWN;
+		} else if (rc) {
+			cause = "invalid-signature";
+			status = INTEGRITY_FAIL;
+		} else {
+			status = INTEGRITY_PASS;
+		}
+		break;
+	default:
+		status = INTEGRITY_UNKNOWN;
+		cause = "unknown-ima-data";
+		break;
+	}
+
+out:
+	if (status != INTEGRITY_PASS) {
+		if ((ima_appraise & IMA_APPRAISE_FIX) &&
+		    (!xattr_value ||
+		     xattr_value->type != EVM_IMA_XATTR_DIGSIG)) {
+			ima_fix_xattr(dentry, iint);
+			status = INTEGRITY_PASS;
+		}
+		integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, filename,
+				    op, cause, rc, 0);
+	} else {
+		iint->flags |= IMA_APPRAISED;
+	}
+	iint->ima_status = status;
+	kfree(xattr_value);
+	return status;
+}
+
+/*
+ * ima_update_xattr - update 'security.ima' hash value
+ */
+void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file)
+{
+	struct dentry *dentry = file->f_dentry;
+	int rc = 0;
+
+	/* do not collect and update hash for digital signatures */
+	if (iint->flags & IMA_DIGSIG)
+		return;
+
+	rc = ima_collect_measurement(iint, file);
+	if (rc < 0)
+		return;
+
+	ima_fix_xattr(dentry, iint);
+}
+
+/**
+ * ima_inode_post_setattr - reflect file metadata changes
+ * @dentry: pointer to the affected dentry
+ *
+ * Changes to a dentry's metadata might result in needing to appraise.
+ *
+ * This function is called from notify_change(), which expects the caller
+ * to lock the inode's i_mutex.
+ */
+void ima_inode_post_setattr(struct dentry *dentry)
+{
+	struct inode *inode = dentry->d_inode;
+	struct integrity_iint_cache *iint;
+	int must_appraise, rc;
+
+	if (!ima_initialized || !ima_appraise || !S_ISREG(inode->i_mode)
+	    || !inode->i_op->removexattr)
+		return;
+
+	must_appraise = ima_must_appraise(inode, MAY_ACCESS, POST_SETATTR);
+	iint = integrity_iint_find(inode);
+	if (iint) {
+		if (must_appraise)
+			iint->flags |= IMA_APPRAISE;
+		else
+			iint->flags &= ~(IMA_APPRAISE | IMA_APPRAISED);
+	}
+	if (!must_appraise)
+		rc = inode->i_op->removexattr(dentry, XATTR_NAME_IMA);
+	return;
+}
+
+/*
+ * ima_protect_xattr - protect 'security.ima'
+ *
+ * Ensure that not just anyone can modify or remove 'security.ima'.
+ */
+static int ima_protect_xattr(struct dentry *dentry, const char *xattr_name,
+			     const void *xattr_value, size_t xattr_value_len)
+{
+	if (strcmp(xattr_name, XATTR_NAME_IMA) == 0) {
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+		return 1;
+	}
+	return 0;
+}
+
+static void ima_reset_appraise_flags(struct inode *inode)
+{
+	struct integrity_iint_cache *iint;
+
+	if (!ima_initialized || !ima_appraise || !S_ISREG(inode->i_mode))
+		return;
+
+	iint = integrity_iint_find(inode);
+	if (!iint)
+		return;
+
+	iint->flags &= ~IMA_DONE_MASK;
+	return;
+}
+
+int ima_inode_setxattr(struct dentry *dentry, const char *xattr_name,
+		       const void *xattr_value, size_t xattr_value_len)
+{
+	int result;
+
+	result = ima_protect_xattr(dentry, xattr_name, xattr_value,
+				   xattr_value_len);
+	if (result == 1) {
+		ima_reset_appraise_flags(dentry->d_inode);
+		result = 0;
+	}
+	return result;
+}
+
+int ima_inode_removexattr(struct dentry *dentry, const char *xattr_name)
+{
+	int result;
+
+	result = ima_protect_xattr(dentry, xattr_name, NULL, 0);
+	if (result == 1) {
+		ima_reset_appraise_flags(dentry->d_inode);
+		result = 0;
+	}
+	return result;
+}