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>
Reported-by: syzkaller<syzkaller@xxxxxxxxxxxxxxxx>
Signed-off-by: George Kennedy<george.kennedy@xxxxxxxxxx>
---
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;
--
1.8.3.1
