vhost/scsi: potential memory corruption (59c816c1) · Commits · 戴 / test

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>

drivers/vhost/scsi.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -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);

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