[PATCH] net: moxa: fix UAF in moxart_mac_probe

[PATCH] net: moxa: fix UAF in moxart_mac_probe

[Pavel Skripkin]

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>
---
 drivers/net/ethernet/moxa/moxart_ether.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/moxa/moxart_ether.c b/drivers/net/ethernet/moxa/moxart_ether.c
index b85733942053..b46bba9f4846 100644
--- a/drivers/net/ethernet/moxa/moxart_ether.c
+++ b/drivers/net/ethernet/moxa/moxart_ether.c
@@ -541,10 +541,8 @@ 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);
-- 
2.32.0

Re: [PATCH] net: moxa: fix UAF in moxart_mac_probe

[patchwork-bot+netdevbpf]

Hello:

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

On Fri,  9 Jul 2021 17:09:53 +0300 you wrote:
> 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;
> 
> [...]

Here is the summary with links:
  - net: moxa: fix UAF in moxart_mac_probe
    https://git.kernel.org/netdev/net/c/c78eaeebe855

You are awesome, thank you!
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