scsi: libfc: Check xid when looking up REC exchanges

We currently can only lookup the local xid, so we need
to reject REC with empty rxid.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/libfc/fc_exch.c b/drivers/scsi/libfc/fc_exch.c
index 44feffa..9921dbb 100644 (file)
--- a/drivers/scsi/libfc/fc_exch.c
+++ b/drivers/scsi/libfc/fc_exch.c
@@ -2005,8 +2005,7 @@ static void fc_exch_els_rec(struct fc_frame *rfp)
        enum fc_els_rjt_reason reason = ELS_RJT_LOGIC;
        enum fc_els_rjt_explan explan;
        u32 sid;
-       u16 rxid;
-       u16 oxid;
+       u16 xid, rxid, oxid;
 
        lport = fr_dev(rfp);
        rp = fc_frame_payload_get(rfp, sizeof(*rp));
@@ -2017,9 +2016,18 @@ static void fc_exch_els_rec(struct fc_frame *rfp)
        rxid = ntohs(rp->rec_rx_id);
        oxid = ntohs(rp->rec_ox_id);
 
-       ep = fc_exch_lookup(lport,
-                           sid == fc_host_port_id(lport->host) ? oxid : rxid);
        explan = ELS_EXPL_OXID_RXID;
+       if (sid == fc_host_port_id(lport->host))
+               xid = oxid;
+       else
+               xid = rxid;
+       if (xid == FC_XID_UNKNOWN) {
+               FC_LPORT_DBG(lport,
+                            "REC request from %x: invalid rxid %x oxid %x\n",
+                            sid, rxid, oxid);
+               goto reject;
+       }
+       ep = fc_exch_lookup(lport, xid);
        if (!ep) {
                FC_LPORT_DBG(lport,
                             "REC request from %x: rxid %x oxid %x not found\n",