Re: [PATCH 5.15.y ] ksmbd: fix slab-out-of-bounds in smb_strndup_from_utf16()

[Greg KH <gregkh@linuxfoundation.org>]

On Wed, Jan 03, 2024 at 09:29:16AM +0900, Namjae Jeon wrote:
> From: Namjae Jeon <linkinjeon@kernel.org>
> 
> [ Upstream commit d10c77873ba1e9e6b91905018e29e196fd5f863d ]
> 
> If ->NameOffset/Length is bigger than ->CreateContextsOffset/Length,
> ksmbd_check_message doesn't validate request buffer it correctly.
> So slab-out-of-bounds warning from calling smb_strndup_from_utf16()
> in smb2_open() could happen. If ->NameLength is non-zero, Set the larger
> of the two sums (Name and CreateContext size) as the offset and length of
> the data area.
> 
> Reported-by: Yang Chaoming <lometsj@live.com>
> Cc: stable@vger.kernel.org
> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
> Signed-off-by: Steve French <stfrench@microsoft.com>
> ---
>  fs/ksmbd/smb2misc.c | 15 ++++++++++++---
>  1 file changed, 12 insertions(+), 3 deletions(-)

Now queued up, thanks.

greg k-h