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.

Reported-by: syzkaller syzkaller@googlegroups.com Signed-off-by: George Kennedy george.kennedy@oracle.com --- 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;