Re: [syzbot] [net?] [virt?] [kvm?] KASAN: slab-use-after-free Read in vhost_task_fn

[Michael S. Tsirkin]

On Tue, Apr 30, 2024 at 05:31:47PM +0800, Edward Adam Davis wrote:
> please test uaf in vhost_task_fn
> 
> #syz test https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git bb7a2467e6be
> diff --git a/kernel/vhost_task.c b/kernel/vhost_task.c
> index 48c289947b99..8800f5acc007 100644
> --- a/kernel/vhost_task.c
> +++ b/kernel/vhost_task.c
> @@ -61,8 +61,8 @@ static int vhost_task_fn(void *data)
>  		set_bit(VHOST_TASK_FLAGS_KILLED, &vtsk->flags);
>  		vtsk->handle_sigkill(vtsk->data);
>  	}
> -	complete(&vtsk->exited);
>  	mutex_unlock(&vtsk->exit_mutex);
> +	complete(&vtsk->exited);
>  
>  	do_exit(0);
>  }


OK so if rebased on latest master by linus then this patch is
sufficient. I squashed it in. Edward, thanks a lot for working
on this! I added Suggested-by tag if you like me to add your
S.O.B too I can do this.