qlcnic: potential dereference null pointer of rx_queue->page_ring

The return value of kcalloc() needs to be checked.
To avoid dereference of null pointer in case of the failure of alloc.
Therefore, it might be better to change the return type of
qlcnic_sriov_alloc_vlans() and return -ENOMEM when alloc fails and
return 0 the others.
Also, qlcnic_sriov_set_guest_vlan_mode() and __qlcnic_pci_sriov_enable()
should deal with the return value of qlcnic_sriov_alloc_vlans().

Fixes: 154d0c8 ("qlcnic: VLAN enhancement for 84XX adapters")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/qlogic/qlcnic/qlcnic_sriov.h

@@ -201,7 +201,7 @@ int qlcnic_sriov_get_vf_vport_info(struct qlcnic_adapter *,
 				   struct qlcnic_info *, u16);
 int qlcnic_sriov_cfg_vf_guest_vlan(struct qlcnic_adapter *, u16, u8);
 void qlcnic_sriov_free_vlans(struct qlcnic_adapter *);
-void qlcnic_sriov_alloc_vlans(struct qlcnic_adapter *);
+int qlcnic_sriov_alloc_vlans(struct qlcnic_adapter *);
 bool qlcnic_sriov_check_any_vlan(struct qlcnic_vf_info *);
 void qlcnic_sriov_del_vlan_id(struct qlcnic_sriov *,
 			      struct qlcnic_vf_info *, u16);

drivers/net/ethernet/qlogic/qlcnic/qlcnic_sriov_common.c

@@ -432,7 +432,7 @@ static int qlcnic_sriov_set_guest_vlan_mode(struct qlcnic_adapter *adapter,
 					    struct qlcnic_cmd_args *cmd)
 {
 	struct qlcnic_sriov *sriov = adapter->ahw->sriov;
-	int i, num_vlans;
+	int i, num_vlans, ret;
 	u16 *vlans;
 
 	if (sriov->allowed_vlans)
@@ -443,7 +443,9 @@ static int qlcnic_sriov_set_guest_vlan_mode(struct qlcnic_adapter *adapter,
 	dev_info(&adapter->pdev->dev, "Number of allowed Guest VLANs = %d\n",
 		 sriov->num_allowed_vlans);
 
-	qlcnic_sriov_alloc_vlans(adapter);
+	ret = qlcnic_sriov_alloc_vlans(adapter);
+	if (ret)
+		return ret;
 
 	if (!sriov->any_vlan)
 		return 0;
@@ -2154,7 +2156,7 @@ static int qlcnic_sriov_vf_resume(struct qlcnic_adapter *adapter)
 	return err;
 }
 
-void qlcnic_sriov_alloc_vlans(struct qlcnic_adapter *adapter)
+int qlcnic_sriov_alloc_vlans(struct qlcnic_adapter *adapter)
 {
 	struct qlcnic_sriov *sriov = adapter->ahw->sriov;
 	struct qlcnic_vf_info *vf;
@@ -2164,7 +2166,11 @@ void qlcnic_sriov_alloc_vlans(struct qlcnic_adapter *adapter)
 		vf = &sriov->vf_info[i];
 		vf->sriov_vlans = kcalloc(sriov->num_allowed_vlans,
 					  sizeof(*vf->sriov_vlans), GFP_KERNEL);
+		if (!vf->sriov_vlans)
+			return -ENOMEM;
 	}
+
+	return 0;
 }
 
 void qlcnic_sriov_free_vlans(struct qlcnic_adapter *adapter)

drivers/net/ethernet/qlogic/qlcnic/qlcnic_sriov_pf.c

@@ -597,7 +597,9 @@ static int __qlcnic_pci_sriov_enable(struct qlcnic_adapter *adapter,
 	if (err)
 		goto del_flr_queue;
 
-	qlcnic_sriov_alloc_vlans(adapter);
+	err = qlcnic_sriov_alloc_vlans(adapter);
+	if (err)
+		goto del_flr_queue;
 
 	return err;