ethernet: ucc_geth: fix use-after-free in ucc_geth_remove()

stable inclusion
from stable-5.10.7
commit 116395a26d957f559e3ef386d2b1bd22d5a9151b
bugzilla: 47429

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

[ Upstream commit e925e0cd ]

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: 80a9fad8 ("ucc_geth: fix module removal")
Signed-off-by: NRasmus Villemoes <rasmus.villemoes@prevas.dk>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: NXie XiuQi <xiexiuqi@huawei.com>

drivers/net/ethernet/freescale/ucc_geth.c

@@ -3934,12 +3934,12 @@ static int ucc_geth_remove(struct platform_device* ofdev)
 	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;
 }