Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754573AbdGNREk (ORCPT ); Fri, 14 Jul 2017 13:04:40 -0400 Received: from mail-oi0-f43.google.com ([209.85.218.43]:32941 "EHLO mail-oi0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753382AbdGNREi (ORCPT ); Fri, 14 Jul 2017 13:04:38 -0400 MIME-Version: 1.0 In-Reply-To: <20170714165453.112098-1-glider@google.com> References: <20170714165453.112098-1-glider@google.com> From: Neal Cardwell Date: Fri, 14 Jul 2017 13:04:06 -0400 Message-ID: Subject: Re: [PATCH] ipv6: initialize treq->txhash in cookie_v6_check() To: Alexander Potapenko Cc: Dmitry Vyukov , kcc@google.com, Eric Dumazet , David Miller , LKML , Netdev Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 924 Lines: 24 On Fri, Jul 14, 2017 at 12:54 PM, Alexander Potapenko wrote: > KMSAN reported use of uninitialized memory in skb_set_hash_from_sk(), > which originated from the TCP request socket created in > cookie_v6_check(): ... > --- a/net/ipv6/syncookies.c > +++ b/net/ipv6/syncookies.c > @@ -216,6 +216,7 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb) > treq->rcv_isn = ntohl(th->seq) - 1; > treq->snt_isn = cookie; > treq->ts_off = 0; > + treq->txhash = 0; > > /* > * We need to lookup the dst_entry to get the correct window size. I would have thought that the same fix is needed in the corresponding line in cookie_v4_check() in net/ipv4/syncookies.c? (I do not see txhash being initialized for the IPv4 side.) If it's not needed for some reason, then it would be worth a comment in the commit description to explain why not. thanks, neal