From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755124Ab2EaGUj (ORCPT ); Thu, 31 May 2012 02:20:39 -0400 Received: from mail-bk0-f46.google.com ([209.85.214.46]:60844 "EHLO mail-bk0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752556Ab2EaGUh (ORCPT ); Thu, 31 May 2012 02:20:37 -0400 Subject: Re: [PATCH] net: sock: validate data_len before allocating skb in sock_alloc_send_pskb() From: Eric Dumazet To: Jason Wang Cc: "Michael S. Tsirkin" , David Miller , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org In-Reply-To: <4FC70BA8.5060200@redhat.com> References: <20120530054702.6146.8503.stgit@amd-6168-8-1.englab.nay.redhat.com> <1338360383.2760.84.camel@edumazet-glaptop> <20120530.030205.1337682162603770949.davem@davemloft.net> <4FC708EE.2020908@redhat.com> <20120531060201.GA13158@redhat.com> <4FC70BA8.5060200@redhat.com> Content-Type: text/plain; charset="UTF-8" Date: Thu, 31 May 2012 08:20:32 +0200 Message-ID: <1338445232.2760.1171.camel@edumazet-glaptop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2012-05-31 at 14:11 +0800, Jason Wang wrote: > Not affected, only code duplication. It's no harm the check the data_len > again for packet sockets, so better to unify the code and fix the issue > in one place? As a matter of fact, we currently allocate order-0 pages, but it could be nice trying to use order-1 or order-2 pages, on arches where PAGE_SIZE is so small (4096 bytes) So lets do this test in sock_alloc_send_pskb() to allow future changes. af_unix is kind of special, because it tries to lower risk of high order linear allocation failures. And for small sizes, it wants linear skbs to have no performance regression (prior kernels were allocating linear skbs)