From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dan Carpenter , Nicholas Bellinger , Wang Long Subject: [PATCH 3.10 32/56] vhost/scsi: potential memory corruption Date: Tue, 29 Sep 2015 15:47:20 +0200 Message-Id: <20150929134701.802407277@linuxfoundation.org> In-Reply-To: <20150929134700.376714360@linuxfoundation.org> References: <20150929134700.376714360@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dan Carpenter 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. Signed-off-by: Dan Carpenter Signed-off-by: Nicholas Bellinger [ The affected function was renamed to vhost_scsi_make_tpg before the vulnerability was announced, I ported it to 3.10 stable and changed the code in function tcm_vhost_make_tpg] Signed-off-by: Wang Long Signed-off-by: Greg Kroah-Hartman --- drivers/vhost/scsi.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/drivers/vhost/scsi.c +++ b/drivers/vhost/scsi.c @@ -1088,7 +1088,7 @@ static void tcm_vhost_send_evt(struct vh * 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; @@ -1894,12 +1894,12 @@ static struct se_portal_group *tcm_vhost 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);