ethtool: Ensure new ring parameters are within bounds during SRINGPARAM

Add a sanity check to ensure that all requested ring parameters
are within bounds, which should reduce errors in driver implementation.

Signed-off-by: Eugenia Emantayev <eugenia@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index fff6314..107b122 100644 (file)
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -1693,14 +1693,23 @@ static int ethtool_get_ringparam(struct net_device *dev, void __user *useraddr)
 
 static int ethtool_set_ringparam(struct net_device *dev, void __user *useraddr)
 {
-       struct ethtool_ringparam ringparam;
+       struct ethtool_ringparam ringparam, max = { .cmd = ETHTOOL_GRINGPARAM };
 
-       if (!dev->ethtool_ops->set_ringparam)
+       if (!dev->ethtool_ops->set_ringparam || !dev->ethtool_ops->get_ringparam)
                return -EOPNOTSUPP;
 
        if (copy_from_user(&ringparam, useraddr, sizeof(ringparam)))
                return -EFAULT;
 
+       dev->ethtool_ops->get_ringparam(dev, &max);
+
+       /* ensure new ring parameters are within the maximums */
+       if (ringparam.rx_pending > max.rx_max_pending ||
+           ringparam.rx_mini_pending > max.rx_mini_max_pending ||
+           ringparam.rx_jumbo_pending > max.rx_jumbo_max_pending ||
+           ringparam.tx_pending > max.tx_max_pending)
+               return -EINVAL;
+
        return dev->ethtool_ops->set_ringparam(dev, &ringparam);
 }