Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit

Pull audit update from Paul Moore:
 "This is one of the larger audit patchsets in recent history,
  consisting of eight patches and almost 400 lines of changes.

  The bulk of the patchset is the new "audit by executable"
  functionality which allows admins to set an audit watch based on the
  executable on disk.  Prior to this, admins could only track an
  application by PID, which has some obvious limitations.

  Beyond the new functionality we also have some refcnt fixes and a few
  minor cleanups"

* 'upstream' of git://git.infradead.org/users/pcmoore/audit:
  fixup: audit: implement audit by executable
  audit: implement audit by executable
  audit: clean simple fsnotify implementation
  audit: use macros for unset inode and device values
  audit: make audit_del_rule() more robust
  audit: fix uninitialized variable in audit_add_rule()
  audit: eliminate unnecessary extra layer of watch parent references
  audit: eliminate unnecessary extra layer of watch references

1 files changed, 216 insertions, 0 deletions

diff --git a/kernel/audit_fsnotify.c b/kernel/audit_fsnotify.c
new file mode 100644
index 000000000000..27c6046c2c3d
--- /dev/null
+++ b/kernel/audit_fsnotify.c
@@ -0,0 +1,216 @@
+/* audit_fsnotify.c -- tracking inodes
+ *
+ * Copyright 2003-2009,2014-2015 Red Hat, Inc.
+ * Copyright 2005 Hewlett-Packard Development Company, L.P.
+ * Copyright 2005 IBM Corporation
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/audit.h>
+#include <linux/kthread.h>
+#include <linux/mutex.h>
+#include <linux/fs.h>
+#include <linux/fsnotify_backend.h>
+#include <linux/namei.h>
+#include <linux/netlink.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/security.h>
+#include "audit.h"
+
+/*
+ * this mark lives on the parent directory of the inode in question.
+ * but dev, ino, and path are about the child
+ */
+struct audit_fsnotify_mark {
+	dev_t dev;		/* associated superblock device */
+	unsigned long ino;	/* associated inode number */
+	char *path;		/* insertion path */
+	struct fsnotify_mark mark; /* fsnotify mark on the inode */
+	struct audit_krule *rule;
+};
+
+/* fsnotify handle. */
+static struct fsnotify_group *audit_fsnotify_group;
+
+/* fsnotify events we care about. */
+#define AUDIT_FS_EVENTS (FS_MOVE | FS_CREATE | FS_DELETE | FS_DELETE_SELF |\
+			 FS_MOVE_SELF | FS_EVENT_ON_CHILD)
+
+static void audit_fsnotify_mark_free(struct audit_fsnotify_mark *audit_mark)
+{
+	kfree(audit_mark->path);
+	kfree(audit_mark);
+}
+
+static void audit_fsnotify_free_mark(struct fsnotify_mark *mark)
+{
+	struct audit_fsnotify_mark *audit_mark;
+
+	audit_mark = container_of(mark, struct audit_fsnotify_mark, mark);
+	audit_fsnotify_mark_free(audit_mark);
+}
+
+char *audit_mark_path(struct audit_fsnotify_mark *mark)
+{
+	return mark->path;
+}
+
+int audit_mark_compare(struct audit_fsnotify_mark *mark, unsigned long ino, dev_t dev)
+{
+	if (mark->ino == AUDIT_INO_UNSET)
+		return 0;
+	return (mark->ino == ino) && (mark->dev == dev);
+}
+
+static void audit_update_mark(struct audit_fsnotify_mark *audit_mark,
+			     struct inode *inode)
+{
+	audit_mark->dev = inode ? inode->i_sb->s_dev : AUDIT_DEV_UNSET;
+	audit_mark->ino = inode ? inode->i_ino : AUDIT_INO_UNSET;
+}
+
+struct audit_fsnotify_mark *audit_alloc_mark(struct audit_krule *krule, char *pathname, int len)
+{
+	struct audit_fsnotify_mark *audit_mark;
+	struct path path;
+	struct dentry *dentry;
+	struct inode *inode;
+	int ret;
+
+	if (pathname[0] != '/' || pathname[len-1] == '/')
+		return ERR_PTR(-EINVAL);
+
+	dentry = kern_path_locked(pathname, &path);
+	if (IS_ERR(dentry))
+		return (void *)dentry; /* returning an error */
+	inode = path.dentry->d_inode;
+	mutex_unlock(&inode->i_mutex);
+
+	audit_mark = kzalloc(sizeof(*audit_mark), GFP_KERNEL);
+	if (unlikely(!audit_mark)) {
+		audit_mark = ERR_PTR(-ENOMEM);
+		goto out;
+	}
+
+	fsnotify_init_mark(&audit_mark->mark, audit_fsnotify_free_mark);
+	audit_mark->mark.mask = AUDIT_FS_EVENTS;
+	audit_mark->path = pathname;
+	audit_update_mark(audit_mark, dentry->d_inode);
+	audit_mark->rule = krule;
+
+	ret = fsnotify_add_mark(&audit_mark->mark, audit_fsnotify_group, inode, NULL, true);
+	if (ret < 0) {
+		audit_fsnotify_mark_free(audit_mark);
+		audit_mark = ERR_PTR(ret);
+	}
+out:
+	dput(dentry);
+	path_put(&path);
+	return audit_mark;
+}
+
+static void audit_mark_log_rule_change(struct audit_fsnotify_mark *audit_mark, char *op)
+{
+	struct audit_buffer *ab;
+	struct audit_krule *rule = audit_mark->rule;
+
+	if (!audit_enabled)
+		return;
+	ab = audit_log_start(NULL, GFP_NOFS, AUDIT_CONFIG_CHANGE);
+	if (unlikely(!ab))
+		return;
+	audit_log_format(ab, "auid=%u ses=%u op=",
+			 from_kuid(&init_user_ns, audit_get_loginuid(current)),
+			 audit_get_sessionid(current));
+	audit_log_string(ab, op);
+	audit_log_format(ab, " path=");
+	audit_log_untrustedstring(ab, audit_mark->path);
+	audit_log_key(ab, rule->filterkey);
+	audit_log_format(ab, " list=%d res=1", rule->listnr);
+	audit_log_end(ab);
+}
+
+void audit_remove_mark(struct audit_fsnotify_mark *audit_mark)
+{
+	fsnotify_destroy_mark(&audit_mark->mark, audit_fsnotify_group);
+	fsnotify_put_mark(&audit_mark->mark);
+}
+
+void audit_remove_mark_rule(struct audit_krule *krule)
+{
+	struct audit_fsnotify_mark *mark = krule->exe;
+
+	audit_remove_mark(mark);
+}
+
+static void audit_autoremove_mark_rule(struct audit_fsnotify_mark *audit_mark)
+{
+	struct audit_krule *rule = audit_mark->rule;
+	struct audit_entry *entry = container_of(rule, struct audit_entry, rule);
+
+	audit_mark_log_rule_change(audit_mark, "autoremove_rule");
+	audit_del_rule(entry);
+}
+
+/* Update mark data in audit rules based on fsnotify events. */
+static int audit_mark_handle_event(struct fsnotify_group *group,
+				    struct inode *to_tell,
+				    struct fsnotify_mark *inode_mark,
+				    struct fsnotify_mark *vfsmount_mark,
+				    u32 mask, void *data, int data_type,
+				    const unsigned char *dname, u32 cookie)
+{
+	struct audit_fsnotify_mark *audit_mark;
+	struct inode *inode = NULL;
+
+	audit_mark = container_of(inode_mark, struct audit_fsnotify_mark, mark);
+
+	BUG_ON(group != audit_fsnotify_group);
+
+	switch (data_type) {
+	case (FSNOTIFY_EVENT_PATH):
+		inode = ((struct path *)data)->dentry->d_inode;
+		break;
+	case (FSNOTIFY_EVENT_INODE):
+		inode = (struct inode *)data;
+		break;
+	default:
+		BUG();
+		return 0;
+	};
+
+	if (mask & (FS_CREATE|FS_MOVED_TO|FS_DELETE|FS_MOVED_FROM)) {
+		if (audit_compare_dname_path(dname, audit_mark->path, AUDIT_NAME_FULL))
+			return 0;
+		audit_update_mark(audit_mark, inode);
+	} else if (mask & (FS_DELETE_SELF|FS_UNMOUNT|FS_MOVE_SELF))
+		audit_autoremove_mark_rule(audit_mark);
+
+	return 0;
+}
+
+static const struct fsnotify_ops audit_mark_fsnotify_ops = {
+	.handle_event =	audit_mark_handle_event,
+};
+
+static int __init audit_fsnotify_init(void)
+{
+	audit_fsnotify_group = fsnotify_alloc_group(&audit_mark_fsnotify_ops);
+	if (IS_ERR(audit_fsnotify_group)) {
+		audit_fsnotify_group = NULL;
+		audit_panic("cannot create audit fsnotify group");
+	}
+	return 0;
+}
+device_initcall(audit_fsnotify_init);