IB/core: For multicast functions, verify that LIDs are multicast LIDs

commit 8561eae6 upstream.

The Infiniband spec defines "A multicast address is defined by a
MGID and a MLID" (section 10.5).  Currently the MLID value is not
validated.

Add check to verify that the MLID value is in the correct address
range.

Fixes: 0c33aeed ("[IB] Add checks to multicast attach and detach")
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Dasaratharaman Chandramouli <dasaratharaman.chandramouli@intel.com>
Signed-off-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
[bwh: Backported to 3.16: use literal number instead of IB_MULTICAST_LID_BASE]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

drivers/infiniband/core/verbs.c

@@ -1346,7 +1346,9 @@ int ib_attach_mcast(struct ib_qp *qp, union ib_gid *gid, u16 lid)
 
 	if (!qp->device->attach_mcast)
 		return -ENOSYS;
-	if (gid->raw[0] != 0xff || qp->qp_type != IB_QPT_UD)
+	if (gid->raw[0] != 0xff || qp->qp_type != IB_QPT_UD ||
+	    lid < 0xC000 ||
+	    lid == be16_to_cpu(IB_LID_PERMISSIVE))
 		return -EINVAL;
 
 	ret = qp->device->attach_mcast(qp, gid, lid);
@@ -1362,7 +1364,9 @@ int ib_detach_mcast(struct ib_qp *qp, union ib_gid *gid, u16 lid)
 
 	if (!qp->device->detach_mcast)
 		return -ENOSYS;
-	if (gid->raw[0] != 0xff || qp->qp_type != IB_QPT_UD)
+	if (gid->raw[0] != 0xff || qp->qp_type != IB_QPT_UD ||
+	    lid < 0xC000 ||
+	    lid == be16_to_cpu(IB_LID_PERMISSIVE))
 		return -EINVAL;
 
 	ret = qp->device->detach_mcast(qp, gid, lid);