[PATCH 4.14 07/57] ethernet: ucc_geth: fix use-after-free in ucc_geth_remove()

Greg Kroah-Hartman
2021-01-11T14:01:01Z

From: Rasmus Villemoes <rasmus.villemoes@prevas.dk>

[ Upstream commit e925e0cd2a705aaacb0b907bb3691fcac3a973a4 ]

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.

Fixes: 80a9fad8e89a ("ucc_geth: fix module removal")
Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/ethernet/freescale/ucc_geth.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/ethernet/freescale/ucc_geth.c
+++ b/drivers/net/ethernet/freescale/ucc_geth.c
@@ -3939,12 +3939,12 @@ static int ucc_geth_remove(struct platfo
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);
+ free_netdev(dev);

return 0;
}