From 59c816c1f24df0204e01851431d3bab3eb76719c Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Thu, 5 Feb 2015 10:37:33 +0300 Subject: [PATCH] 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 Signed-off-by: Nicholas Bellinger --- drivers/vhost/scsi.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c index daf10b7fa311..ab4811f749f5 100644 --- a/drivers/vhost/scsi.c +++ b/drivers/vhost/scsi.c @@ -1249,7 +1249,7 @@ vhost_scsi_send_evt(struct vhost_scsi *vs, * 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 @@ vhost_scsi_make_tpg(struct se_wwn *wwn, 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); -- 2.20.1