IB/hfi1: Improve TID validity checking

Correct and improve validity checking of user supplied TIDs.
A tidctrl value of 0 is invalid.  Verify that the final
index is in range, not an intermediate value.
Signed-off-by: Dean Luick <dean.luick@cornelisnetworks.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Link: https://lore.kernel.org/r/167329105916.1472990.9915542468337924727.stgit@awfm-02.cornelisnetworks.comSigned-off-by: Leon Romanovsky <leon@kernel.org>

drivers/infiniband/hw/hfi1/user_exp_rcv.c

@@ -741,20 +741,20 @@ static int unprogram_rcvarray(struct hfi1_filedata *fd, u32 tidinfo,
 	struct hfi1_ctxtdata *uctxt = fd->uctxt;
 	struct hfi1_devdata *dd = uctxt->dd;
 	struct tid_rb_node *node;
-	u8 tidctrl = EXP_TID_GET(tidinfo, CTRL);
+	u32 tidctrl = EXP_TID_GET(tidinfo, CTRL);
 	u32 tididx = EXP_TID_GET(tidinfo, IDX) << 1, rcventry;
 
-	if (tididx >= uctxt->expected_count) {
-		dd_dev_err(dd, "Invalid RcvArray entry (%u) index for ctxt %u\n",
-			   tididx, uctxt->ctxt);
-		return -EINVAL;
-	}
-
-	if (tidctrl == 0x3)
+	if (tidctrl == 0x3 || tidctrl == 0x0)
 		return -EINVAL;
 
 	rcventry = tididx + (tidctrl - 1);
 
+	if (rcventry >= uctxt->expected_count) {
+		dd_dev_err(dd, "Invalid RcvArray entry (%u) index for ctxt %u\n",
+			   rcventry, uctxt->ctxt);
+		return -EINVAL;
+	}
+
 	node = fd->entry_to_rb[rcventry];
 	if (!node || node->rcventry != (uctxt->expected_base + rcventry))
 		return -EBADF;