From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH RFC net-next] net: Assert napi_gro_cb size against skb->cb[] Date: Fri, 31 Jul 2015 13:44:42 -0700 (PDT) Message-ID: <20150731.134442.1572308169975939249.davem@davemloft.net> References: <1438368669-659-1-git-send-email-f.fainelli@gmail.com> <20150731202403.GB20471@breakpoint.cc> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: f.fainelli@gmail.com, netdev@vger.kernel.org, herbert@gondor.apana.org.au, daniel@iogearbox.net, edumazet@google.com To: fw@strlen.de Return-path: Received: from shards.monkeyblade.net ([149.20.54.216]:50790 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752373AbbGaUoq (ORCPT ); Fri, 31 Jul 2015 16:44:46 -0400 In-Reply-To: <20150731202403.GB20471@breakpoint.cc> Sender: netdev-owner@vger.kernel.org List-ID: From: Florian Westphal Date: Fri, 31 Jul 2015 22:24:03 +0200 > Florian Fainelli wrote: >> On 64-bits hosts, napi_gro_cb is 48 bytes, which is exactly the size of >> skb->cb[], while on 32-bits hosts it is 36 bytes, but if it were to >> grow, we would not be catching a size inflation as we should. >> --- >> net/core/dev.c | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/net/core/dev.c b/net/core/dev.c >> index 4870c3556a5a..20bc82604b75 100644 >> --- a/net/core/dev.c >> +++ b/net/core/dev.c >> @@ -4115,6 +4115,8 @@ static void skb_gro_reset_offset(struct sk_buff *skb) >> const struct skb_shared_info *pinfo = skb_shinfo(skb); >> const skb_frag_t *frag0 = &pinfo->frags[0]; >> >> + BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct napi_gro_cb)); > > commit c3c7c254b2e8cd99b0adf288c2a1bddacd7ba255 > already added a check for this. Indeed.