On 2021/12/14 23:45, 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>
George,
FYI, you should not send patches that need backporting to
stable@xxxxxxxxxxxxxxx. The above Cc: tag will do that automatically.
> Reported-by: syzkaller<syzkaller@xxxxxxxxxxxxxxxx>
> Signed-off-by: George Kennedy<george.kennedy@xxxxxxxxxx>
> ---
> Used the Maintainers suggested fix.
The usual way of writing this is something like:
Changes from v1:
* Blah
This way, if you need a v3, v4, etc, you can keep the previous changes
description and add new ones on top.
>
> drivers/ata/libata-scsi.c | 15 +++++++++++++--
> 1 file changed, 13 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
> index 1b84d55..313e947 100644
> --- a/drivers/ata/libata-scsi.c
> +++ b/drivers/ata/libata-scsi.c
> @@ -2859,8 +2859,19 @@ static unsigned int ata_scsi_pass_thru(struct ata_queued_cmd *qc)
> goto invalid_fld;
> }
>
> - if (ata_is_ncq(tf->protocol) && (cdb[2 + cdb_offset] & 0x3) == 0)
> - tf->protocol = ATA_PROT_NCQ_NODATA;
> + if ((cdb[2 + cdb_offset] & 0x3) == 0) {
> + /*
> + * When T_LENGTH is zero (No data is transferred), dir should
> + * be DMA_NONE.
> + */
> + if (scmd->sc_data_direction != DMA_NONE) {
> + fp = 2 + cdb_offset;
> + goto invalid_fld;
> + }
> +
> + if (ata_is_ncq(tf->protocol))
> + tf->protocol = ATA_PROT_NCQ_NODATA;
> + }
>
> /* enable LBA */
> tf->flags |= ATA_TFLAG_LBA;
This look OK to me. Will apply.
--
Damien Le Moal
Western Digital Research
