i40e: add check for return from find_first_bit call

The find_first_bit function will return the size passed to search
if the first set bit is not found. This patch adds the check in case
that happens as the return value would be used as the index in an array
and that would have caused the out-of-bounds access.

Detected by CoverityScan, CID 1295969 Out-of-bounds access

Signed-off-by: Lihong Yang <lihong.yang@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

diff --git a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
index 8372790..125dcd1 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
@@ -306,6 +306,10 @@ static void i40e_config_irq_link_list(struct i40e_vf *vf, u16 vsi_id,
        next_q = find_first_bit(&linklistmap,
                                (I40E_MAX_VSI_QP *
                                 I40E_VIRTCHNL_SUPPORTED_QTYPES));
+       if (unlikely(next_q == (I40E_MAX_VSI_QP *
+                               I40E_VIRTCHNL_SUPPORTED_QTYPES)))
+               goto irq_list_done;
+
        vsi_queue_id = next_q / I40E_VIRTCHNL_SUPPORTED_QTYPES;
        qtype = next_q % I40E_VIRTCHNL_SUPPORTED_QTYPES;
        pf_queue_id = i40e_vc_get_pf_queue_id(vf, vsi_id, vsi_queue_id);