[PATCH 11/20] ethernet: ucc_geth: fix use-after-free in ucc_geth_remove()

From: Rasmus Villemoes
Date: Sat Dec 05 2020 - 14:21:18 EST


ugeth is the netdiv_priv() part of the netdevice. Accessing the memory
pointed to by ugeth (such as done by ucc_geth_memclean() and the two
of_node_puts) after free_netdev() is thus use-after-free.

Signed-off-by: Rasmus Villemoes <rasmus.villemoes@xxxxxxxxx>
---
drivers/net/ethernet/freescale/ucc_geth.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/freescale/ucc_geth.c b/drivers/net/ethernet/freescale/ucc_geth.c
index b132fcfc7c17..ba911d05d36d 100644
--- a/drivers/net/ethernet/freescale/ucc_geth.c
+++ b/drivers/net/ethernet/freescale/ucc_geth.c
@@ -3895,13 +3895,13 @@ static int ucc_geth_remove(struct platform_device* ofdev)
struct ucc_geth_private *ugeth = netdev_priv(dev);
struct device_node *np = ofdev->dev.of_node;

- unregister_netdev(dev);
- free_netdev(dev);
ucc_geth_memclean(ugeth);
if (of_phy_is_fixed_link(np))
of_phy_deregister_fixed_link(np);
of_node_put(ugeth->ug_info->tbi_node);
of_node_put(ugeth->ug_info->phy_node);
+ unregister_netdev(dev);
+ free_netdev(dev);

return 0;
}
--
2.23.0