v4.19.13 snapshot.
diff --git a/security/apparmor/path.c b/security/apparmor/path.c
new file mode 100644
index 0000000..9d5de1d
--- /dev/null
+++ b/security/apparmor/path.c
@@ -0,0 +1,221 @@
+/*
+ * AppArmor security module
+ *
+ * This file contains AppArmor function for pathnames
+ *
+ * Copyright (C) 1998-2008 Novell/SUSE
+ * Copyright 2009-2010 Canonical Ltd.
+ *
+ * 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/magic.h>
+#include <linux/mount.h>
+#include <linux/namei.h>
+#include <linux/nsproxy.h>
+#include <linux/path.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/fs_struct.h>
+
+#include "include/apparmor.h"
+#include "include/path.h"
+#include "include/policy.h"
+
+/* modified from dcache.c */
+static int prepend(char **buffer, int buflen, const char *str, int namelen)
+{
+ buflen -= namelen;
+ if (buflen < 0)
+ return -ENAMETOOLONG;
+ *buffer -= namelen;
+ memcpy(*buffer, str, namelen);
+ return 0;
+}
+
+#define CHROOT_NSCONNECT (PATH_CHROOT_REL | PATH_CHROOT_NSCONNECT)
+
+/* If the path is not connected to the expected root,
+ * check if it is a sysctl and handle specially else remove any
+ * leading / that __d_path may have returned.
+ * Unless
+ * specifically directed to connect the path,
+ * OR
+ * if in a chroot and doing chroot relative paths and the path
+ * resolves to the namespace root (would be connected outside
+ * of chroot) and specifically directed to connect paths to
+ * namespace root.
+ */
+static int disconnect(const struct path *path, char *buf, char **name,
+ int flags, const char *disconnected)
+{
+ int error = 0;
+
+ if (!(flags & PATH_CONNECT_PATH) &&
+ !(((flags & CHROOT_NSCONNECT) == CHROOT_NSCONNECT) &&
+ our_mnt(path->mnt))) {
+ /* disconnected path, don't return pathname starting
+ * with '/'
+ */
+ error = -EACCES;
+ if (**name == '/')
+ *name = *name + 1;
+ } else {
+ if (**name != '/')
+ /* CONNECT_PATH with missing root */
+ error = prepend(name, *name - buf, "/", 1);
+ if (!error && disconnected)
+ error = prepend(name, *name - buf, disconnected,
+ strlen(disconnected));
+ }
+
+ return error;
+}
+
+/**
+ * d_namespace_path - lookup a name associated with a given path
+ * @path: path to lookup (NOT NULL)
+ * @buf: buffer to store path to (NOT NULL)
+ * @name: Returns - pointer for start of path name with in @buf (NOT NULL)
+ * @flags: flags controlling path lookup
+ * @disconnected: string to prefix to disconnected paths
+ *
+ * Handle path name lookup.
+ *
+ * Returns: %0 else error code if path lookup fails
+ * When no error the path name is returned in @name which points to
+ * to a position in @buf
+ */
+static int d_namespace_path(const struct path *path, char *buf, char **name,
+ int flags, const char *disconnected)
+{
+ char *res;
+ int error = 0;
+ int connected = 1;
+ int isdir = (flags & PATH_IS_DIR) ? 1 : 0;
+ int buflen = aa_g_path_max - isdir;
+
+ if (path->mnt->mnt_flags & MNT_INTERNAL) {
+ /* it's not mounted anywhere */
+ res = dentry_path(path->dentry, buf, buflen);
+ *name = res;
+ if (IS_ERR(res)) {
+ *name = buf;
+ return PTR_ERR(res);
+ }
+ if (path->dentry->d_sb->s_magic == PROC_SUPER_MAGIC &&
+ strncmp(*name, "/sys/", 5) == 0) {
+ /* TODO: convert over to using a per namespace
+ * control instead of hard coded /proc
+ */
+ error = prepend(name, *name - buf, "/proc", 5);
+ goto out;
+ } else
+ error = disconnect(path, buf, name, flags,
+ disconnected);
+ goto out;
+ }
+
+ /* resolve paths relative to chroot?*/
+ if (flags & PATH_CHROOT_REL) {
+ struct path root;
+ get_fs_root(current->fs, &root);
+ res = __d_path(path, &root, buf, buflen);
+ path_put(&root);
+ } else {
+ res = d_absolute_path(path, buf, buflen);
+ if (!our_mnt(path->mnt))
+ connected = 0;
+ }
+
+ /* handle error conditions - and still allow a partial path to
+ * be returned.
+ */
+ if (!res || IS_ERR(res)) {
+ if (PTR_ERR(res) == -ENAMETOOLONG) {
+ error = -ENAMETOOLONG;
+ *name = buf;
+ goto out;
+ }
+ connected = 0;
+ res = dentry_path_raw(path->dentry, buf, buflen);
+ if (IS_ERR(res)) {
+ error = PTR_ERR(res);
+ *name = buf;
+ goto out;
+ };
+ } else if (!our_mnt(path->mnt))
+ connected = 0;
+
+ *name = res;
+
+ if (!connected)
+ error = disconnect(path, buf, name, flags, disconnected);
+
+ /* Handle two cases:
+ * 1. A deleted dentry && profile is not allowing mediation of deleted
+ * 2. On some filesystems, newly allocated dentries appear to the
+ * security_path hooks as a deleted dentry except without an inode
+ * allocated.
+ */
+ if (d_unlinked(path->dentry) && d_is_positive(path->dentry) &&
+ !(flags & (PATH_MEDIATE_DELETED | PATH_DELEGATE_DELETED))) {
+ error = -ENOENT;
+ goto out;
+ }
+
+out:
+ /*
+ * Append "/" to the pathname. The root directory is a special
+ * case; it already ends in slash.
+ */
+ if (!error && isdir && ((*name)[1] != '\0' || (*name)[0] != '/'))
+ strcpy(&buf[aa_g_path_max - 2], "/");
+
+ return error;
+}
+
+/**
+ * aa_path_name - get the pathname to a buffer ensure dir / is appended
+ * @path: path the file (NOT NULL)
+ * @flags: flags controlling path name generation
+ * @buffer: buffer to put name in (NOT NULL)
+ * @name: Returns - the generated path name if !error (NOT NULL)
+ * @info: Returns - information on why the path lookup failed (MAYBE NULL)
+ * @disconnected: string to prepend to disconnected paths
+ *
+ * @name is a pointer to the beginning of the pathname (which usually differs
+ * from the beginning of the buffer), or NULL. If there is an error @name
+ * may contain a partial or invalid name that can be used for audit purposes,
+ * but it can not be used for mediation.
+ *
+ * We need PATH_IS_DIR to indicate whether the file is a directory or not
+ * because the file may not yet exist, and so we cannot check the inode's
+ * file type.
+ *
+ * Returns: %0 else error code if could retrieve name
+ */
+int aa_path_name(const struct path *path, int flags, char *buffer,
+ const char **name, const char **info, const char *disconnected)
+{
+ char *str = NULL;
+ int error = d_namespace_path(path, buffer, &str, flags, disconnected);
+
+ if (info && error) {
+ if (error == -ENOENT)
+ *info = "Failed name lookup - deleted entry";
+ else if (error == -EACCES)
+ *info = "Failed name lookup - disconnected path";
+ else if (error == -ENAMETOOLONG)
+ *info = "Failed name lookup - name too long";
+ else
+ *info = "Failed name lookup";
+ }
+
+ *name = str;
+
+ return error;
+}