Re: [PATCH v2] carl9170: tx: fix an incorrect use of list iterator

From: Kalle Valo
Date: Tue Apr 05 2022 - 05:52:56 EST

Xiaomeng Tong <xiam0nd.tong@xxxxxxxxx> wrote:

> If the previous list_for_each_entry_continue_rcu() don't exit early
> (no goto hit inside the loop), the iterator 'cvif' after the loop
> will be a bogus pointer to an invalid structure object containing
> the HEAD (&ar->vif_list). As a result, the use of 'cvif' after that
> will lead to a invalid memory access (i.e., 'cvif->id': the invalid
> pointer dereference when return back to/after the callsite in the
> carl9170_update_beacon()).
> The original intention should have been to return the valid 'cvif'
> when found in list, NULL otherwise. So just return NULL when no
> entry found, to fix this bug.
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: 1f1d9654e183c ("carl9170: refactor carl9170_update_beacon")
> Signed-off-by: Xiaomeng Tong <xiam0nd.tong@xxxxxxxxx>
> Signed-off-by: Kalle Valo <quic_kvalo@xxxxxxxxxxx>

Christian, is this ok to take?