[PATCH] net: ethernet: aeroflex: fix UAF in greth_of_remove

[PATCH] net: ethernet: aeroflex: fix UAF in greth_of_remove

[Pavel Skripkin]

static int greth_of_remove(struct platform_device *of_dev)
{
...
	struct greth_private *greth = netdev_priv(ndev);
...
	unregister_netdev(ndev);
	free_netdev(ndev);

	of_iounmap(&of_dev->resource[0], greth->regs, resource_size(&of_dev->resource[0]));
...
}

greth is netdev private data, but it is used
after free_netdev(). It can cause use-after-free when accessing greth
pointer. So, fix it by moving free_netdev() after of_iounmap()
call.

Fixes: d4c41139df6e ("net: Add Aeroflex Gaisler 10/100/1G Ethernet MAC driver")
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
---
 drivers/net/ethernet/aeroflex/greth.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/aeroflex/greth.c b/drivers/net/ethernet/aeroflex/greth.c
index d77fafbc1530..c560ad06f0be 100644
--- a/drivers/net/ethernet/aeroflex/greth.c
+++ b/drivers/net/ethernet/aeroflex/greth.c
@@ -1539,10 +1539,11 @@ static int greth_of_remove(struct platform_device *of_dev)
 	mdiobus_unregister(greth->mdio);
 
 	unregister_netdev(ndev);
-	free_netdev(ndev);
 
 	of_iounmap(&of_dev->resource[0], greth->regs, resource_size(&of_dev->resource[0]));
 
+	free_netdev(ndev);
+
 	return 0;
 }
 
-- 
2.32.0

Re: [PATCH] net: ethernet: aeroflex: fix UAF in greth_of_remove

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (refs/heads/master):

On Fri, 18 Jun 2021 17:57:31 +0300 you wrote:
> static int greth_of_remove(struct platform_device *of_dev)
> {
> ...
> 	struct greth_private *greth = netdev_priv(ndev);
> ...
> 	unregister_netdev(ndev);
> 	free_netdev(ndev);
> 
> [...]

Here is the summary with links:
  - net: ethernet: aeroflex: fix UAF in greth_of_remove
    https://git.kernel.org/netdev/net/c/e3a5de6d81d8

You are awesome, thank you!
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