Return-path: Received: from mail-wm0-f51.google.com ([74.125.82.51]:33053 "EHLO mail-wm0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751808AbcDKHwg convert rfc822-to-8bit (ORCPT ); Mon, 11 Apr 2016 03:52:36 -0400 Received: by mail-wm0-f51.google.com with SMTP id f198so133844449wme.0 for ; Mon, 11 Apr 2016 00:52:35 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20160411074438.GA15227@mwanda> References: <20160411074438.GA15227@mwanda> Date: Mon, 11 Apr 2016 09:52:34 +0200 Message-ID: (sfid-20160411_095240_086059_CFD1B0BD) Subject: Re: [patch] ath10k: add some sanity checks From: Michal Kazior To: Dan Carpenter Cc: Kalle Valo , "ath10k@lists.infradead.org" , linux-wireless , kernel-janitors@vger.kernel.org Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: On 11 April 2016 at 09:44, Dan Carpenter wrote: > Smatch complains that since "ev->peer_id" comes from skb->data that > means we can't trust it and have to do a bounds check on it to prevent > an array overflow. > > Fixes: 6942726f7f7b ('ath10k: add fast peer_map lookup') > Signed-off-by: Dan Carpenter > > diff --git a/drivers/net/wireless/ath/ath10k/txrx.c b/drivers/net/wireless/ath/ath10k/txrx.c > index 9369411..fd6ba69 100644 > --- a/drivers/net/wireless/ath/ath10k/txrx.c > +++ b/drivers/net/wireless/ath/ath10k/txrx.c > @@ -190,6 +190,9 @@ void ath10k_peer_map_event(struct ath10k_htt *htt, > struct ath10k *ar = htt->ar; > struct ath10k_peer *peer; > > + if (ev->peer_id >= ATH10K_MAX_NUM_PEER_IDS) > + return; > + This will lead to a timeout in the other part of the code so printing a warning here will make it easier to understand the failure, e.g. ath10k_warn(ar, "received htt peer map event with idx out of bounds: %hu\n", ev->peer_id); > spin_lock_bh(&ar->data_lock); > peer = ath10k_peer_find(ar, ev->vdev_id, ev->addr); > if (!peer) { > @@ -218,6 +221,9 @@ void ath10k_peer_unmap_event(struct ath10k_htt *htt, > struct ath10k *ar = htt->ar; > struct ath10k_peer *peer; > > + if (ev->peer_id >= ATH10K_MAX_NUM_PEER_IDS) > + return; Ditto but s/map/unmap. Anyway, good catch, thanks! Michał