[net-next 03/17] igc: Fix locking issue when retrieving NFC rules

[Jeff Kirsher]

From: Andre Guedes <andre.gue...@intel.com>

Access to NFC rules stored in adapter->nfc_rule_list is protect by
adapter->nfc_rule_lock. The functions igc_ethtool_get_nfc_rule()
and igc_ethtool_get_nfc_rules() are missing to hold the lock while
accessing rule objects.

Signed-off-by: Andre Guedes <andre.gue...@intel.com>
Tested-by: Aaron Brown <aaron.f.br...@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirs...@intel.com>
---
 drivers/net/ethernet/intel/igc/igc_ethtool.c | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/intel/igc/igc_ethtool.c 
b/drivers/net/ethernet/intel/igc/igc_ethtool.c
index 24aa321f64b5..decd29fbfbe2 100644
--- a/drivers/net/ethernet/intel/igc/igc_ethtool.c
+++ b/drivers/net/ethernet/intel/igc/igc_ethtool.c
@@ -939,16 +939,18 @@ static int igc_ethtool_get_nfc_rule(struct igc_adapter 
*adapter,
 
        cmd->data = IGC_MAX_RXNFC_RULES;
 
+       spin_lock(&adapter->nfc_rule_lock);
+
        hlist_for_each_entry(rule, &adapter->nfc_rule_list, nfc_node) {
                if (fsp->location <= rule->location)
                        break;
        }
 
        if (!rule || fsp->location != rule->location)
-               return -EINVAL;
+               goto out;
 
        if (!rule->filter.match_flags)
-               return -EINVAL;
+               goto out;
 
        fsp->flow_type = ETHER_FLOW;
        fsp->ring_cookie = rule->action;
@@ -976,7 +978,12 @@ static int igc_ethtool_get_nfc_rule(struct igc_adapter 
*adapter,
                eth_broadcast_addr(fsp->m_u.ether_spec.h_source);
        }
 
+       spin_unlock(&adapter->nfc_rule_lock);
        return 0;
+
+out:
+       spin_unlock(&adapter->nfc_rule_lock);
+       return -EINVAL;
 }
 
 static int igc_ethtool_get_nfc_rules(struct igc_adapter *adapter,
@@ -988,13 +995,19 @@ static int igc_ethtool_get_nfc_rules(struct igc_adapter 
*adapter,
 
        cmd->data = IGC_MAX_RXNFC_RULES;
 
+       spin_lock(&adapter->nfc_rule_lock);
+
        hlist_for_each_entry(rule, &adapter->nfc_rule_list, nfc_node) {
-               if (cnt == cmd->rule_cnt)
+               if (cnt == cmd->rule_cnt) {
+                       spin_unlock(&adapter->nfc_rule_lock);
                        return -EMSGSIZE;
+               }
                rule_locs[cnt] = rule->location;
                cnt++;
        }
 
+       spin_unlock(&adapter->nfc_rule_lock);
+
        cmd->rule_cnt = cnt;
 
        return 0;
-- 
2.26.2