scsi: iscsi: Verify lengths on passthrough PDUs

commit f9dbdf97a5bd92b1a49cee3d591b55b11fd7a6d5 upstream.

Open-iSCSI sends passthrough PDUs over netlink, but the kernel should be
verifying that the provided PDU header and data lengths fall within the
netlink message to prevent accessing beyond that in memory.

Cc: stable@vger.kernel.org
Reported-by: Adam Nichols <adam@grimm-co.com>
Reviewed-by: Lee Duncan <lduncan@suse.com>
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Chris Leech <cleech@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
index f8cc5949fb065bc29baf71e5346790de5cdc3c31..4f4d2d65a4a7044c5d35402b1796b2255931aa1e 100644 (file)
--- a/drivers/scsi/scsi_transport_iscsi.c
+++ b/drivers/scsi/scsi_transport_iscsi.c
@@ -3525,6 +3525,7 @@ static int
 iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, uint32_t *group)
 {
        int err = 0;
+       u32 pdu_len;
        struct iscsi_uevent *ev = nlmsg_data(nlh);
        struct iscsi_transport *transport = NULL;
        struct iscsi_internal *priv;
@@ -3640,6 +3641,14 @@ iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, uint32_t *group)
                        err = -EINVAL;
                break;
        case ISCSI_UEVENT_SEND_PDU:
+               pdu_len = nlh->nlmsg_len - sizeof(*nlh) - sizeof(*ev);
+
+               if ((ev->u.send_pdu.hdr_size > pdu_len) ||
+                   (ev->u.send_pdu.data_size > (pdu_len - ev->u.send_pdu.hdr_size))) {
+                       err = -EINVAL;
+                       break;
+               }
+
                conn = iscsi_conn_lookup(ev->u.send_pdu.sid, ev->u.send_pdu.cid);
                if (conn)
                        ev->r.retcode = transport->send_pdu(conn,