Linux-libre 4.3.2-gnu

1 files changed, 216 insertions, 0 deletions

diff --git a/kernel/audit_fsnotify.c b/kernel/audit_fsnotify.c
new file mode 100644
index 000000000..27c6046c2
--- /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);