On Fri, Apr 12, 2019 at 10:51 PM Tom Talpey <ttalpey@xxxxxxxxxxxxx> wrote:
>
> > -----Original Message-----
> > From: linux-cifs-owner@xxxxxxxxxxxxxxx <linux-cifs-owner@xxxxxxxxxxxxxxx> On
> > Behalf Of Ronnie Sahlberg
> > Sent: Thursday, April 11, 2019 11:06 PM
> > To: linux-cifs <linux-cifs@xxxxxxxxxxxxxxx>
> > Cc: Steve French <smfrench@xxxxxxxxx>; Ronnie Sahlberg
> > <lsahlber@xxxxxxxxxx>
> > Subject: [PATCH] cifs: fix bi-directional fsctl passthrough calls
> >
> > SMB2 Ioctl responses from servers may respond with both the request blob
> > from
> > the client followed by the actual reply blob for ioctls that are bi-directional.
> >
> > In that case we can not assume that the reply blob comes immediately after
> > the
> > ioctl response structure.
> >
> > This fixes FSCTLs such as SMB2:FSCTL_QUERY_ALLOCATED_RANGES
> >
> > Signed-off-by: Ronnie Sahlberg <lsahlber@xxxxxxxxxx>
> > ---
> > fs/cifs/smb2ops.c | 4 +++-
> > 1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
> > index 0b7e2be2a781..768f35ea63cf 100644
> > --- a/fs/cifs/smb2ops.c
> > +++ b/fs/cifs/smb2ops.c
> > @@ -1467,7 +1467,9 @@ smb2_ioctl_query_info(const unsigned int xid,
> > rc = -EFAULT;
> > goto iqinf_exit;
> > }
> > - if (copy_to_user(pqi + 1, &io_rsp[1], qi.input_buffer_length)) {
> > + if (copy_to_user((char *)pqi + sizeof(struct smb_query_info),
> > + (char *)io_rsp + le32_to_cpu(io_rsp-
> > >OutputOffset),
> > + qi.input_buffer_length)) {
>
> Shouldn't this validate that OutputOffset, for a length of input_buffer_length, falls completely within the bounds of the response, before copying?
I think copy_to_user handles that
>
>
> > rc = -EFAULT;
> > goto iqinf_exit;
> > }
> > --
> > 2.13.6
>
