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@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
