fuse: readdir: check for slash in names

commit efeb9e60 upstream.

Userspace can add names containing a slash character to the directory
listing.  Don't allow this as it could cause all sorts of trouble.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fs/fuse/dir.c

@@ -1175,6 +1175,8 @@ static int parse_dirfile(char *buf, size_t nbytes, struct file *file,
 			return -EIO;
 		if (reclen > nbytes)
 			break;
+		if (memchr(dirent->name, '/', dirent->namelen) != NULL)
+			return -EIO;
 
 		over = filldir(dstbuf, dirent->name, dirent->namelen,
 			       file->f_pos, dirent->ino, dirent->type);
@@ -1323,6 +1325,8 @@ static int parse_dirplusfile(char *buf, size_t nbytes, struct file *file,
 			return -EIO;
 		if (reclen > nbytes)
 			break;
+		if (memchr(dirent->name, '/', dirent->namelen) != NULL)
+			return -EIO;
 
 		if (!over) {
 			/* We fill entries into dstbuf only as much as