i40e: Fix a few potential VF dereferences

In some functions we might be doing potential dereference
without a check. This patch puts the check in place for all these
functions. Also fix the "for loops" so that we increment VF at the
right place so that we always do it even if we are short-circuiting
the loop through continue.

Change-ID: Id4276cfb1e841031bb7b6d6790c414242f364a9f
Signed-off-by: Anjali Singhai Jain <anjali.singhai@intel.com>
Tested-by: Jim Young <jamesx.m.young@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c

@@ -1003,11 +1003,19 @@ int i40e_pci_sriov_configure(struct pci_dev *pdev, int num_vfs)
 static int i40e_vc_send_msg_to_vf(struct i40e_vf *vf, u32 v_opcode,
 				  u32 v_retval, u8 *msg, u16 msglen)
 {
-	struct i40e_pf *pf = vf->pf;
-	struct i40e_hw *hw = &pf->hw;
-	int abs_vf_id = vf->vf_id + hw->func_caps.vf_base_id;
+	struct i40e_pf *pf;
+	struct i40e_hw *hw;
+	int abs_vf_id;
 	i40e_status aq_ret;
 
+	/* validate the request */
+	if (!vf || vf->vf_id >= vf->pf->num_alloc_vfs)
+		return -EINVAL;
+
+	pf = vf->pf;
+	hw = &pf->hw;
+	abs_vf_id = vf->vf_id + hw->func_caps.vf_base_id;
+
 	/* single place to detect unsuccessful return values */
 	if (v_retval) {
 		vf->num_invalid_msgs++;
@@ -1928,10 +1936,10 @@ static void i40e_vc_vf_broadcast(struct i40e_pf *pf,
 {
 	struct i40e_hw *hw = &pf->hw;
 	struct i40e_vf *vf = pf->vf;
-	int abs_vf_id;
 	int i;
 
-	for (i = 0; i < pf->num_alloc_vfs; i++) {
+	for (i = 0; i < pf->num_alloc_vfs; i++, vf++) {
+		int abs_vf_id = vf->vf_id + hw->func_caps.vf_base_id;
 		/* Not all vfs are enabled so skip the ones that are not */
 		if (!test_bit(I40E_VF_STAT_INIT, &vf->vf_states) &&
 		    !test_bit(I40E_VF_STAT_ACTIVE, &vf->vf_states))
@@ -1940,10 +1948,8 @@ static void i40e_vc_vf_broadcast(struct i40e_pf *pf,
 		/* Ignore return value on purpose - a given VF may fail, but
 		 * we need to keep going and send to all of them
 		 */
-		abs_vf_id = vf->vf_id + hw->func_caps.vf_base_id;
 		i40e_aq_send_msg_to_vf(hw, abs_vf_id, v_opcode, v_retval,
 				       msg, msglen, NULL);
-		vf++;
 	}
 }
 
@@ -1959,12 +1965,12 @@ void i40e_vc_notify_link_state(struct i40e_pf *pf)
 	struct i40e_hw *hw = &pf->hw;
 	struct i40e_vf *vf = pf->vf;
 	struct i40e_link_status *ls = &pf->hw.phy.link_info;
-	int abs_vf_id = vf->vf_id + hw->func_caps.vf_base_id;
 	int i;
 
 	pfe.event = I40E_VIRTCHNL_EVENT_LINK_CHANGE;
 	pfe.severity = I40E_PF_EVENT_SEVERITY_INFO;
-	for (i = 0; i < pf->num_alloc_vfs; i++) {
+	for (i = 0; i < pf->num_alloc_vfs; i++, vf++) {
+		int abs_vf_id = vf->vf_id + hw->func_caps.vf_base_id;
 		if (vf->link_forced) {
 			pfe.event_data.link_event.link_status = vf->link_up;
 			pfe.event_data.link_event.link_speed =
@@ -1977,8 +1983,6 @@ void i40e_vc_notify_link_state(struct i40e_pf *pf)
 		i40e_aq_send_msg_to_vf(hw, abs_vf_id, I40E_VIRTCHNL_OP_EVENT,
 				       0, (u8 *)&pfe, sizeof(pfe),
 				       NULL);
-		vf++;
-		abs_vf_id = vf->vf_id + hw->func_caps.vf_base_id;
 	}
 }
 
@@ -2009,6 +2013,10 @@ void i40e_vc_notify_vf_reset(struct i40e_vf *vf)
 	struct i40e_virtchnl_pf_event pfe;
 	int abs_vf_id;
 
+	/* validate the request */
+	if (!vf || vf->vf_id >= vf->pf->num_alloc_vfs)
+		return;
+
 	/* verify if the VF is in either init or active before proceeding */
 	if (!test_bit(I40E_VF_STAT_INIT, &vf->vf_states) &&
 	    !test_bit(I40E_VF_STAT_ACTIVE, &vf->vf_states))