From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH net v2] skbuff: Fix skb checksum flag on skb pull Date: Mon, 04 Jan 2016 23:08:04 -0500 (EST) Message-ID: <20160104.230804.2220774053197810472.davem@davemloft.net> References: <1442951873-4803-1-git-send-email-pshelar@nicira.com> <20150924.140931.1967362456389755405.davem@davemloft.net> <1451498745.8255.35.camel@edumazet-glaptop2.roam.corp.google.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: pshelar@nicira.com, netdev@vger.kernel.org, willemdebruijn.kernel@gmail.com To: eric.dumazet@gmail.com Return-path: Received: from shards.monkeyblade.net ([149.20.54.216]:51442 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753884AbcAEEIH (ORCPT ); Mon, 4 Jan 2016 23:08:07 -0500 In-Reply-To: <1451498745.8255.35.camel@edumazet-glaptop2.roam.corp.google.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Eric Dumazet Date: Wed, 30 Dec 2015 13:05:45 -0500 > On Thu, 2015-09-24 at 14:09 -0700, David Miller wrote: >> From: Pravin B Shelar >> Date: Tue, 22 Sep 2015 12:57:53 -0700 >> >> > VXLAN device can receive skb with checksum partial. But the checksum >> > offset could be in outer header which is pulled on receive. This results >> > in negative checksum offset for the skb. Such skb can cause the assert >> > failure in skb_checksum_help(). Following patch fixes the bug by setting >> > checksum-none while pulling outer header. >> > >> > Following is the kernel panic msg from old kernel hitting the bug. >> ... >> > Reported-by: Anupam Chanda >> > Signed-off-by: Pravin B Shelar >> >> Applied, thanks. > > > It looks like we also should clear skb->csum ? > > __skb_checksum_complete() definitely would be confused by garbage in > skb->csum Pravin, please take a look at this.