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>
[bwh: Backported to 3.2: drop changes to parse_dirplusfile() which we
 don't have]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Rui Xiang <rui.xiang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 373b25145e011068f589f0a7db1a21215250cb69..9966cae5a9e5bc596ad1f0f958f95515181c057a 100644 (file)
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -1103,6 +1103,8 @@ 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);