--- zzzz-none-000/linux-3.10.107/fs/autofs4/dev-ioctl.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/fs/autofs4/dev-ioctl.c	2021-02-04 17:41:59.000000000 +0000
@@ -103,6 +103,9 @@
 	if (tmp.size < sizeof(tmp))
 		return ERR_PTR(-EINVAL);
 
+	if (tmp.size > (PATH_MAX + sizeof(tmp)))
+		return ERR_PTR(-ENAMETOOLONG);
+
 	res = memdup_user(in, tmp.size);
 	if (!IS_ERR(res))
 		res->size = tmp.size;
@@ -187,13 +190,14 @@
 	return 0;
 }
 
+/* Find the topmost mount satisfying test() */
 static int find_autofs_mount(const char *pathname,
 			     struct path *res,
 			     int test(struct path *path, void *data),
 			     void *data)
 {
 	struct path path;
-	int err = kern_path(pathname, 0, &path);
+	int err = kern_path_mountpoint(AT_FDCWD, pathname, &path, 0);
 	if (err)
 		return err;
 	err = -ENOENT;
@@ -201,10 +205,9 @@
 		if (path.dentry->d_sb->s_magic == AUTOFS_SUPER_MAGIC) {
 			if (test(&path, data)) {
 				path_get(&path);
-				if (!err) /* already found some */
-					path_put(res);
 				*res = path;
 				err = 0;
+				break;
 			}
 		}
 		if (!follow_up(&path))
@@ -350,6 +353,7 @@
 {
 	int pipefd;
 	int err = 0;
+	struct pid *new_pid = NULL;
 
 	if (param->setpipefd.pipefd == -1)
 		return -EINVAL;
@@ -361,7 +365,17 @@
 		mutex_unlock(&sbi->wq_mutex);
 		return -EBUSY;
 	} else {
-		struct file *pipe = fget(pipefd);
+		struct file *pipe;
+
+		new_pid = get_task_pid(current, PIDTYPE_PGID);
+
+		if (ns_of_pid(new_pid) != ns_of_pid(sbi->oz_pgrp)) {
+			AUTOFS_WARN("Not allowed to change PID namespace");
+			err = -EINVAL;
+			goto out;
+		}
+
+		pipe = fget(pipefd);
 		if (!pipe) {
 			err = -EBADF;
 			goto out;
@@ -371,12 +385,13 @@
 			fput(pipe);
 			goto out;
 		}
-		sbi->oz_pgrp = task_pgrp_nr(current);
+		swap(sbi->oz_pgrp, new_pid);
 		sbi->pipefd = pipefd;
 		sbi->pipe = pipe;
 		sbi->catatonic = 0;
 	}
 out:
+	put_pid(new_pid);
 	mutex_unlock(&sbi->wq_mutex);
 	return err;
 }
@@ -439,7 +454,7 @@
 	ino = autofs4_dentry_ino(path.dentry);
 	if (ino) {
 		err = 0;
-		autofs4_expire_wait(path.dentry);
+		autofs4_expire_wait(path.dentry, 0);
 		spin_lock(&sbi->fs_lock);
 		param->requester.uid = from_kuid_munged(current_user_ns(), ino->uid);
 		param->requester.gid = from_kgid_munged(current_user_ns(), ino->gid);
@@ -490,12 +505,11 @@
  * mount if there is one or 0 if it isn't a mountpoint.
  *
  * If we aren't supplied with a file descriptor then we
- * lookup the nameidata of the path and check if it is the
- * root of a mount. If a type is given we are looking for
- * a particular autofs mount and if we don't find a match
- * we return fail. If the located nameidata path is the
- * root of a mount we return 1 along with the super magic
- * of the mount or 0 otherwise.
+ * lookup the path and check if it is the root of a mount.
+ * If a type is given we are looking for a particular autofs
+ * mount and if we don't find a match we return fail. If the
+ * located path is the root of a mount we return 1 along with
+ * the super magic of the mount or 0 otherwise.
  *
  * In both cases the the device number (as returned by
  * new_encode_dev()) is also returned.
@@ -523,9 +537,11 @@
 
 	if (!fp || param->ioctlfd == -1) {
 		if (autofs_type_any(type))
-			err = kern_path(name, LOOKUP_FOLLOW, &path);
+			err = kern_path_mountpoint(AT_FDCWD,
+						   name, &path, LOOKUP_FOLLOW);
 		else
-			err = find_autofs_mount(name, &path, test_by_type, &type);
+			err = find_autofs_mount(name, &path,
+						test_by_type, &type);
 		if (err)
 			goto out;
 		devid = new_encode_dev(path.dentry->d_sb->s_dev);
@@ -661,12 +677,6 @@
 			goto out;
 		}
 
-		if (!fp->f_op) {
-			err = -ENOTTY;
-			fput(fp);
-			goto out;
-		}
-
 		sbi = autofs_dev_ioctl_sbi(fp);
 		if (!sbi || sbi->magic != AUTOFS_SBI_MAGIC) {
 			err = -EINVAL;
@@ -731,7 +741,7 @@
 MODULE_ALIAS("devname:autofs");
 
 /* Register/deregister misc character device */
-int autofs_dev_ioctl_init(void)
+int __init autofs_dev_ioctl_init(void)
 {
 	int r;