Subject: Re: [PATCH] drivers/net/ethernet/neterion/vxge: Fix a use-after-free bug in vxge-main.c

From: Jakub Kicinski <[email-masked]>
Date: Mon, 20 Jun 2022 08:56:49 -0700

On Sun, 19 Jun 2022 11:00:13 +0000 [email-masked]
wrote:
> Hello:
> 
> This patch was applied to netdev/net.git (master)
> by David S. Miller <[email-masked]>:
> 
> On Sun, 19 Jun 2022 22:14:54 +0800 you wrote:
> > The pointer vdev points to a memory region adjacent to a net_device
> > structure ndev, which is a field of hldev. At line 4740, the invocation
> > to vxge_device_unregister unregisters device hldev, and it also releases
> > the memory region pointed by vdev->bar0. At line 4743, the freed memory
> > region is referenced (i.e., iounmap(vdev->bar0)), resulting in a
> > use-after-free vulnerability. We can fix the bug by calling iounmap
> > before vxge_device_unregister.
> > 
> > [...]  
> 
> Here is the summary with links:
>   - drivers/net/ethernet/neterion/vxge: Fix a use-after-free bug in vxge-main.c
>     https://git.kernel.org/netdev/net/c/8fc74d18639a
> 
> You are awesome, thank you!

😭😭😭

Jon, if you care about this driver staying upstream please send 
a correct fix (on top of this change since it's already merged).