[PATCH 3.18 067/120] e1000: ensure to free old tx/rx rings in set_ringparam()

[Greg Kroah-Hartman]

3.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Bo Chen <chenbo@xxxxxxx>

[ Upstream commit ee400a3f1bfe7004a3e14b81c38ccc5583c26295 ]

In 'e1000_set_ringparam()', the tx_ring and rx_ring are updated with new value
and the old tx/rx rings are freed only when the device is up. There are resource
leaks on old tx/rx rings when the device is not up. This bug is reported by COD,
a tool for testing kernel module binaries I am building.

This patch fixes the bug by always calling 'kfree()' on old tx/rx rings in
'e1000_set_ringparam()'.

Signed-off-by: Bo Chen <chenbo@xxxxxxx>
Reviewed-by: Alexander Duyck <alexander.h.duyck@xxxxxxxxx>
Tested-by: Aaron Brown <aaron.f.brown@xxxxxxxxx>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@xxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/ethernet/intel/e1000/e1000_ethtool.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/net/ethernet/intel/e1000/e1000_ethtool.c
+++ b/drivers/net/ethernet/intel/e1000/e1000_ethtool.c
@@ -646,14 +646,14 @@ static int e1000_set_ringparam(struct ne
 		adapter->tx_ring = tx_old;
 		e1000_free_all_rx_resources(adapter);
 		e1000_free_all_tx_resources(adapter);
-		kfree(tx_old);
-		kfree(rx_old);
 		adapter->rx_ring = rxdr;
 		adapter->tx_ring = txdr;
 		err = e1000_up(adapter);
 		if (err)
 			goto err_setup;
 	}
+	kfree(tx_old);
+	kfree(rx_old);
 
 	clear_bit(__E1000_RESETTING, &adapter->flags);
 	return 0;