vhost/scsi: potential memory corruption
This code in vhost_scsi_make_tpg() is confusing because we limit "tpgt"
to UINT_MAX but the data type of "tpg->tport_tpgt" and that is a u16.
I looked at the context and it turns out that in
vhost_scsi_set_endpoint(), "tpg->tport_tpgt" is used as an offset into
the vs_tpg[] array which has VHOST_SCSI_MAX_TARGET (256) elements so
anything higher than 255 then it is invalid. I have made that the limit
now.
In vhost_scsi_send_evt() we mask away values higher than 255, but now
that the limit has changed, we don't need the mask.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index daf10b7..ab4811f 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -1249,7 +1249,7 @@
* lun[4-7] need to be zero according to virtio-scsi spec.
*/
evt->event.lun[0] = 0x01;
- evt->event.lun[1] = tpg->tport_tpgt & 0xFF;
+ evt->event.lun[1] = tpg->tport_tpgt;
if (lun->unpacked_lun >= 256)
evt->event.lun[2] = lun->unpacked_lun >> 8 | 0x40 ;
evt->event.lun[3] = lun->unpacked_lun & 0xFF;
@@ -2120,12 +2120,12 @@
struct vhost_scsi_tport, tport_wwn);
struct vhost_scsi_tpg *tpg;
- unsigned long tpgt;
+ u16 tpgt;
int ret;
if (strstr(name, "tpgt_") != name)
return ERR_PTR(-EINVAL);
- if (kstrtoul(name + 5, 10, &tpgt) || tpgt > UINT_MAX)
+ if (kstrtou16(name + 5, 10, &tpgt) || tpgt >= VHOST_SCSI_MAX_TARGET)
return ERR_PTR(-EINVAL);
tpg = kzalloc(sizeof(struct vhost_scsi_tpg), GFP_KERNEL);