ksmbd: return end of file for reads past a named stream's data

A READ on a non-empty named stream at or beyond its end fails with
STATUS_INVALID_PARAMETER. ksmbd_vfs_stream_read() returns -EINVAL when
the offset is not below the stream length, and smb2_read() maps -EINVAL
to that status.

smb2_read() already turns a zero-byte read into STATUS_END_OF_FILE, the
status a regular file returns at its end, and an empty stream already
takes that path. Return 0 instead of -EINVAL so that non-empty streams
do the same. Clients that read a stream until end of file otherwise get
an error once they have read all of its data.

The buffered copychunk path converts a zero-byte source read to -EIO,
as it does for a regular file that shrinks during copying.

Fixes: 2ae1a6cc4302 ("cifsd: fix potential read overflow in ksmbd_vfs_stream_read()")
Cc: stable@vger.kernel.org
Signed-off-by: DaeMyung Kang <charsyam@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>

0 files changed, 0 insertions, 0 deletions