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@vger.kernel.org Reported-by: syzkallersyzkaller@googlegroups.com Signed-off-by: George Kennedygeorge.kennedy@oracle.com --- Used the Maintainers suggested fix.

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;