[PATCH 4.9 35/71] net: ethernet: fix potential use-after-free in ec_bhf_remove
From: Sasha Levin <sashal@kernel.org>
Date: 2021-06-28 15:19:35
Also in:
lkml
Subsystem:
beckhoff cx5020 ethercat master driver, networking drivers, the rest · Maintainers:
Dariusz Marcinkiewicz, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Pavel Skripkin <redacted>
[ Upstream commit 9cca0c2d70149160407bda9a9446ce0c29b6e6c6 ]
static void ec_bhf_remove(struct pci_dev *dev)
{
...
struct ec_bhf_priv *priv = netdev_priv(net_dev);
unregister_netdev(net_dev);
free_netdev(net_dev);
pci_iounmap(dev, priv->dma_io);
pci_iounmap(dev, priv->io);
...
}
priv is netdev private data, but it is used
after free_netdev(). It can cause use-after-free when accessing priv
pointer. So, fix it by moving free_netdev() after pci_iounmap()
calls.
Fixes: 6af55ff52b02 ("Driver for Beckhoff CX5020 EtherCAT master module.")
Signed-off-by: Pavel Skripkin <redacted>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/ec_bhf.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/ec_bhf.c b/drivers/net/ethernet/ec_bhf.c
index f7b42483921c..0ade0c6d81ee 100644
--- a/drivers/net/ethernet/ec_bhf.c
+++ b/drivers/net/ethernet/ec_bhf.c@@ -589,10 +589,12 @@ static void ec_bhf_remove(struct pci_dev *dev) struct ec_bhf_priv *priv = netdev_priv(net_dev); unregister_netdev(net_dev); - free_netdev(net_dev); pci_iounmap(dev, priv->dma_io); pci_iounmap(dev, priv->io); + + free_netdev(net_dev); + pci_release_regions(dev); pci_clear_master(dev); pci_disable_device(dev);
--
2.30.2