fuse: readdir: check for slash in names

commit efeb9e60d48f7778fdcad4a0f3ad9ea9b19e5dfd 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>

1 files changed, 4 insertions, 0 deletions

diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index a30c60d5ce4f..e67b13de2ebc 100644
--- a/fs/fuse/dir.c
+++ b/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