> -----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?
> rc = -EFAULT;
> goto iqinf_exit;
> }
> --
> 2.13.6
