Patch "vhost/scsi: potential memory corruption" has been added to the 3.14-stable tree

This is a note to let you know that I've just added the patch titled

vhost/scsi: potential memory corruption

to the 3.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
vhost-scsi-potential-memory-corruption.patch
and it can be found in the queue-3.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Dan Carpenter <[email protected]>
Date: Thu, 5 Feb 2015 10:37:33 +0300
Subject: vhost/scsi: potential memory corruption

From: Dan Carpenter <[email protected]>

commit 59c816c1f24df0204e01851431d3bab3eb76719c upstream.

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.

---
 drivers/vhost/scsi.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

@@ -1139,7 +1139,7 @@ tcm_vhost_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;

@@ -2004,12 +2004,12 @@ tcm_vhost_make_tpg(struct se_wwn *wwn,
 			struct tcm_vhost_tport, tport_wwn);
 
 	struct tcm_vhost_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 tcm_vhost_tpg), GFP_KERNEL);

Patches currently in stable-queue which might be from [email protected] are

queue-3.14/vhost-scsi-potential-memory-corruption.patch