fuse: readdir: check for slash in names

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>
Cc: stable@vger.kernel.org

1 files changed, 4 insertions, 0 deletions

diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index c8334f75c8c9..8fec28ff4a0d 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -1174,6 +1174,8 @@ 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;
 
                 if (!dir_emit(ctx, dirent->name, dirent->namelen,
                                dirent->ino, dirent->type))
@@ -1320,6 +1322,8 @@ 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