bonding: bond_slave_info_query() fix

bond_slave_info_query() should keep a read lock while accessing slave info,
or risk accessing stale data and corruption.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Jay Vosburgh <fubar@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 16 deletions

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 63369b6b14d4..67515b78ff91 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -2213,33 +2213,24 @@ static int bond_slave_info_query(struct net_device *bond_dev, struct ifslave *in
 {
         struct bonding *bond = netdev_priv(bond_dev);
         struct slave *slave;
-        int i, found = 0;
-
-        if (info->slave_id < 0) {
-                return -ENODEV;
-        }
+        int i, res = -ENODEV;
 
         read_lock(&bond->lock);
 
         bond_for_each_slave(bond, slave, i) {
                 if (i == (int)info->slave_id) {
-                        found = 1;
+                        res = 0;
+                        strcpy(info->slave_name, slave->dev->name);
+                        info->link = slave->link;
+                        info->state = slave->state;
+                        info->link_failure_count = slave->link_failure_count;
                         break;
                 }
         }
 
         read_unlock(&bond->lock);
 
-        if (found) {
-                strcpy(info->slave_name, slave->dev->name);
-                info->link = slave->link;
-                info->state = slave->state;
-                info->link_failure_count = slave->link_failure_count;
-        } else {
-                return -ENODEV;
-        }
-
-        return 0;
+        return res;
 }
 
 /*-------------------------------- Monitoring -------------------------------*/