On 2021/12/14 0:33, George Kennedy wrote:
> Avoid data corruption by rejecting pass-through commands where
> T_LENGTH is zero (No data is transferred) and the dma direction
> is not DMA_NONE.
>
> Cc:<stable@xxxxxxxxxxxxxxx> # 5.4.y
5.4 only ? What about other LTS versions ? They do not have that bug ?
> Reported-by: syzkaller<syzkaller@xxxxxxxxxxxxxxxx>
> Signed-off-by: George Kennedy<george.kennedy@xxxxxxxxxx>
> ---
> drivers/ata/libata-scsi.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
> index 1b84d55..d428392 100644
> --- a/drivers/ata/libata-scsi.c
> +++ b/drivers/ata/libata-scsi.c
> @@ -2859,6 +2859,12 @@ static unsigned int ata_scsi_pass_thru(struct ata_queued_cmd *qc)
> goto invalid_fld;
> }
>
> + /* if T_LENGTH is zero (No data is transferred), then dir should be DMA_NONE */
> + if ((cdb[2 + cdb_offset] & 3) == 0 && scmd->sc_data_direction != DMA_NONE) {
> + fp = 2 + cdb_offset;
> + goto invalid_fld;
> + }
> +
> if (ata_is_ncq(tf->protocol) && (cdb[2 + cdb_offset] & 0x3) == 0)
> tf->protocol = ATA_PROT_NCQ_NODATA;
>
> -- 1.8.3.1
>
--
Damien Le Moal
Western Digital Research
