net: moxa: fix UAF in moxart_mac_probe

commit c78eaeebe855fd93f2e77142ffd0404a54070d84 upstream.

In case of netdev registration failure the code path will
jump to init_fail label:

init_fail:
	netdev_err(ndev, "init failed\n");
	moxart_mac_free_memory(ndev);
irq_map_fail:
	free_netdev(ndev);
	return ret;

So, there is no need to call free_netdev() before jumping
to error handling path, since it can cause UAF or double-free
bug.

Fixes: 6c821bd9edc9 ("net: Add MOXA ART SoCs ethernet driver")
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/ethernet/moxa/moxart_ether.c b/drivers/net/ethernet/moxa/moxart_ether.c
index 374e691b11da6a8b34c05e2ceca6dd220f6549ab..295b5176bcf1e56cc8ebe01e0afd9f87aba7e58e 100644 (file)
--- a/drivers/net/ethernet/moxa/moxart_ether.c
+++ b/drivers/net/ethernet/moxa/moxart_ether.c
@@ -518,10 +518,8 @@ static int moxart_mac_probe(struct platform_device *pdev)
        SET_NETDEV_DEV(ndev, &pdev->dev);
 
        ret = register_netdev(ndev);
-       if (ret) {
-               free_netdev(ndev);
+       if (ret)
                goto init_fail;
-       }
 
        netdev_dbg(ndev, "%s: IRQ=%d address=%pM\n",
                   __func__, ndev->irq, ndev->dev_addr);