Re: [PATCH] staging: r8188eu: fix NULL check for rcu pointer

From: Greg Kroah-Hartman
Date: Tue Jan 31 2023 - 10:12:38 EST


On Tue, Jan 31, 2023 at 10:00:57AM +0100, Martin Kaiser wrote:
> Fix the NULL check for padapter->pnetdev->rx_handler_data.
>
> The current code calls rcu_dereference while it holds the rcu read lock
> and checks the pointer after releasing the lock. An rcu pointer may only be
> used between calls to rcu_read_lock and rcu_read_unlock.
>
> Replace the check with rcu_access_pointer. My understanding is that this
> function returns the value of the pointer and needs no locking. We can
> then check the pointer but we must not dereference it.
>
> Signed-off-by: Martin Kaiser <martin@xxxxxxxxx>

What commit id does this fix?

thanks,

greg k-h